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? semiconductor components industries, llc, 2005 january, 2005 ? rev. 0 1 publication order number ncv7510/d ncv7510 flexmos programmable peak and hold pwm mosfet predriver the ncv7510 high side mosfet predriver is a fully programmable automotive grade product for driving solenoids or other unipolar actuators. the product is optimized for common?rail diesel fuel injection applications and includes an additional synchronous clamp mosfet predriver. peak and hold currents, peak dwell time and other features are programmable via the device's spi port. load current is continuously sampled and compared to the programmable 7?bit peak/hold dac values while the load self?modulates to maintain the desired currents at each of the peak and hold points. passive fault diagnostics monitor and protect the mosfets when a fault is detected. fault data is available via spi and an open?drain fault output provides immediate fault notification to a host controller. the flexmos family of products offers application scalability through choice of external mosfets. features ? 4 mhz 16?bit spi communication ? 3.3 / 5.0 v compatible inputs ? bootstrap for high side mosfet ? synchronous clamp drive ? cross conduction suppression ? self?protection ? overcurrent and overvoltage ? antisaturation ? fault diagnostics ? short to battery/gnd ? open circuit / shorted load ? overvoltage ? open?drain fault output ? programmable ? peak / hold current pwm thresholds ? overcurrent and overvoltage ? antisaturation thresholds ? peak dwell time ? ncv prefix for automotive and other applications requiring site and control changes benefits ? scalable by choice of mosfets ? reduced load power consumption ? low host controller overhead ? low standby current device package shipping 2 ordering information NCV7510DW so?20l 37 units/rail NCV7510DWr2 so?20l 1000 tape & reel 1 20 http://onsemi.com so?20l dw suffix case 751d marking diagram pin connections 2for information on tape and reel specifications, including part orientation and tape sizes, please refer to our tape and reel packaging specification brochure, brd8011/d. http://onsemi.com 20 1 ncv7510 awlyyww a = assembly location wl = wafer lot yy = year ww = work week drn gate src clamp pgnd sns+ sns? dgnd control sclk so loop fault si ocp 120 ena pclk csb v b v dd
ncv7510 http://onsemi.com 2 clamp drive src clamp gate ocp fet drive control sense amp 16?bit spi csb sclk so si pclk fault diagnostics vref control fault por ovsd drn ena hysteretic mux control gate drive 4x sns+ sns? 8?bit timer over current antisat detection 7?bit dac pgnd dgnd loop figure 1. block diagram v dd v dd v b
ncv7510 http://onsemi.com 3 drn gate src clamp pgnd sns+ sns? dgnd vdd vb control sclk so loop fault si ocp ena pclk csb ncv7510 m1 ntd32n06 m2 ntd32n06 rg + c bulk2 rb ra rpu +5v c boot rlim bat spi host controller filter d1 d2 d3 d5 d6 + c bulk1 injector 3 injector 2 injector 1 injector 4 rsns ntd32n06 ntd32n06 ntd32n06 ntd32n06 d4 mmbz9v1 rs m6 m5 m4 m3 figure 2. application diagram
ncv7510 http://onsemi.com 4 package pin descriptions package pin# pin symbol function 1 ena logic input for enable. 2 control logic input for pwm cycle control. 3 pclk logic input for clock or logic level control of dwell timer. 4 csb logic input for active low chip select. 5 sclk spi clock input. 6 si spi serial data input. 7 so spi serial data output. 8 loop control loop state output. 9 fault open?drain fault output. 10 ocp overcurrent program input. 11 v dd logic supply voltage input; clamp predriver voltage. 12 dgnd supply return; device substrate. 13 sns? current sense negative input. 14 sns+ current sense positive input. 15 pgnd high current supply return; clamp antisaturation reference node. 16 clamp clamp mosfet gate drive output. 17 src hs and clamp mosfet antisaturation diagnostic input. 18 gate hs mosfet gate drive output. 19 drn hs mosfet drain antisaturation / overvoltage diagnostic input. 20 v b bootstrapped gate predriver voltage. drn gate src clamp pgnd sns+ sns? dgnd control sclk so loop fault si ocp 120 ena pclk csb v b v dd
ncv7510 http://onsemi.com 5 pin function descriptions ena: cmos input with hysteresis logically anded with the control input to command the predriver outputs. this input has an active pulldown current source. control: cmos input with hysteresis logically anded with the ena input to command the predriver outputs. this input has an active pulldown current source. pclk: buffered cmos input with hysteresis. this input controls which dac register pair is selected for load current comparison. the input is programmed via auxiliary register ($01) bit d 3 to respond to a clock signal (aux d 3 =0 default at por) or a logic level (aux d 3 =1.) the pin presents a 12 pf maximum load to the controller. csb: cmos input with hysteresis. this input is the active?low chip select input that enables serial data transfer between the host controller and the device. this input has an active pullup current source. sclk: buffered cmos input with hysteresis. this input is the synchronizing clock input for serial data transfer between the micro controller and the device. the pin presents a 12 pf maximum load to the controller. si: buffered cmos input with hysteresis. this pin is the data input to the device's spi shift register. serial data received at this input is transferred from the host controller to the shift register under the control of the csb and sclk inputs. the pin presents a 12 pf maximum load to the controller. this input has an active pulldown current source. so: the cmos compatible line driver at this pin is the data output from the device's spi shift register. serial data transmitted at this output is transferred from the shift register to the host controller under the control of the csb and sclk inputs. the pin is capable of driving 200 pf at 4 mhz and is hi?z when the csb input is high. loop: the cmos compatible driver at this pin reflects the state of the control loop. a logic low indicates that load current is less than the programmed dac reference. fault: an open?drain low voltage nmos output at this pin provides immediate fault indication to a connected host controller. an external resistor is normally connected between this pin and v dd . dgnd: device substrate voltage and v dd return path for mixed signal functions. this pin is the circuit common reference point. ocp: this analog comparator input supplies a reference voltage to the device's overcurrent fault detection. when the voltage at this pin is less than 4.5 v, the applied voltage is the overcurrent reference voltage. when the voltage is greater than 4.5 v, an internal 3.0 v overcurrent reference is used. the voltage at this pin must not exceed v dd . applying approximately v dd + 1.4 v will place the ncv7510 in test mode and suspend normal operation. the user is advised to avoid activating the test mode. v dd : +5.0 vpower supply input. the voltage at this pin initiates power?on reset, supplies power to internal mixed?signal functions and supplies gate charge to the external clamp mosfet. a low esr external bulk capacitor connected between v dd and pgnd is recommended to supply transient gate charge. several internal reference voltages are derived from v dd . sns?: the inverting input to the analog current sense amplifier. this input should be kelvin connected directly to the external current sense resistor's negative terminal. sns+: the noninverting input to the analog current sense amplifier. this input should be kelvin connected directly to the external current sense resistor's positive terminal. pgnd: return path for the gate and clamp predriver transient currents and the lower input to the clamp antisaturation detection comparator. this pin should be star?connected to the clamp mosfet's source and the external v dd bulk charge capacitor's negative terminal. clamp: external clamp mosfet predrive output. this output switches the clamp mosfet's gate between v dd and pgnd. src: lower input to the gate antisaturation detection comparator and upper input to the clamp antisaturation detector. gate: external hs mosfet predrive output. this output switches the hs mosfet's gate between v b and pgnd. drn: upper input to the gate antisaturation detection comparator, overvoltage detection input, and powerup interlock input. this pin should be connected directly to the hs mosfet's drain terminal. vb: bootstrap or boost input voltage. this input supplies gate charge to the external hs mosfet.
ncv7510 http://onsemi.com 6 maximum ratings ( voltages are with respect to device substrate.) rating symbol value unit dc supply voltage (note 1) vdrn ?0.3 to 45 v v dd ?0.3 to 7.0 v vdrn peak transient voltage (note 2) vdrn (pk) 45 v vb pin voltage v b ?2.0 to 50 v gate pin voltage v gate ?2.0 to 50 v vb to gate differential voltage v b ? v gate 50 v src pin voltage v src ?2.0 to 45 v logic level input/output voltage (so, si, sclk, csb, ena, control, pclk, fault, loop) v i/o ?0.3 to 7.0 v sense amplifier input voltage v sns+ ?0.3 to 45 v v sns? ?0.3 to 7.0 v overcurrent comparator input voltage v ocp ?0.3 to 7.0 v junction temperature tj 150 c storage temperature range t stg ?65 to 150 c peak reflow soldering temperature: lead?free (60 to 150 seconds at 217 c) (note 3) 265 peak c maximum ratings are those values beyond which device damage can occur. maximum ratings applied to the device are individual str ess limit values (not normal operating conditions) and are not valid simultaneously. if these limits are exceeded, device functional operation i s not implied, damage may occur and reliability may be affected. 1. reverse vdrn protection must be included in the application circuit. 2. vdrn transient voltage suppression must be included in the application circuit. 3. for additional information, see or download on semiconductor's soldering and mounting techniques reference manual, solderrm/d , and application note and8003/d. attributes characteristic value unit esd capability (all pins) human body model charged device model > 3.0 > 1.0 kv kv moisture sensitivity (note 3) msl 1 package thermal resistance junctiontoambient, r ja junctiontocase, r jc 55 9.0 c/w c/w
ncv7510 http://onsemi.com 7 electrical characteristics (5 v < v drn < 26 v, 4.75 v < v dd < 5.25 v, ?40 c < t j < 125 c, unless otherwise specified.) (note 4 ) characteristic conditions min typ max unit drn input input current v drn = 12.8 v, v dd = 0 v v drn = 26 v, v dd =5.25 v ? 0.5 5.0 2.0 a ma power?on lockout threshold v dd = 0 v, gate predriver locked out 0.7 1.5 v over?voltage lockout gate predriver disabled, clamp predriver active auxiliary register bit 6 = 1 28 32 36 v over?voltage hysteresis 0.1 0.8 2.0 v v b input input bias current v b = 24 v 0.7 1.5 ma v dd supply operating current v drn = 14 v 3.5 7.0 ma power?on reset threshold predrivers disabled, v dd rising 3.0 3.5 4.4 v power?on reset hysteresis ? 0.25 ? v digital i/o v in high ena, control, si, sclk, csb, pclk 2.2 v v in low ena, control, si, sclk, csb, pclk 0.8 v v in hysteresis ena, control, si, sclk, csb, pclk 0.6 1.2 v input pulldown current ena, control, si: v in = v dd 25 a input pullup current csb: v in = 0 v ?25 a so low voltage i sink = 1 ma 0.4 v so high voltage i source = 1 ma v dd ? 1.0 v loop low voltage i sink = 0.1 ma 0.5 v loop high voltage i source = 0.1 ma v dd ? 1.0 v loop output response delay (see figure 3) t loop(hl) ; c loop = 50 pf t loop(lh) ; c loop = 50 pf 0.5 0.5 1.2 1.2 s s fault low voltage fault active, i fault = 0.5 ma 0.1 0.5 v pclk input input capacitance (note 5) 12 pf clock frequency auxiliary register bit 3 = 0 (note 5) 0 20 mhz dac reference select delay auxiliary register bit 3 = 1 (note 5) 3.0 s
ncv7510 http://onsemi.com 8 electrical characteristics (continued) (5 v < vdrn < 26 v, 4.75 v < v dd < 5.25 v, ?40 c < t j < 125 c, unless otherwise specified.) (note 4 ) characteristic conditions min typ max unit gate and clamp predrivers gate output r ds(on) high v b = 7.3 v, v b ?v gate = 0.5 v 20 50 gate output r ds(on) low v b = 7.3 v, v gate = 0.5 v 20 50 gate output delay (see figure 4) t p(lh) ; ena or control high to gate high c gate =2 nf 0.8 1.6 s t p(hl) ; ena or control low to gate low c gate =2 nf 0.3 0.6 s gate response delay (see figure 4) t dly(gr) ;sns+ falling to gate rising v dd =5.0 v, vdrn=10 v, v b =20 v, v src following v gate , v dac =20% fs, c gate =2 nf 0.4 1.6 s t dly(gf) ;sns+ rising to gate falling v dd =5.0 v, vdrn=10 v, v b =20 v, v src following v gate , v dac =80% fs, c gate =2 nf 0.4 1.6 s gate output low hold time (see figure 5) v dd = 5.0 v, c gate =2 nf 5.0 10 15 s gate output pulldown (hi?z) 20 60 150 k clamp output r ds(on) high v dd = 5.0 v, v dd ?v clamp = 0.5 v 20 50 clamp output r ds(on) low v dd = 5.0 v, v clamp = 0.5 v 20 50 clamp output pulldown 50 200 500 k clamp output delay ena or control input low to clamp output low; (note 5) 3.0 s current sense amplifier input bias current sns+, sns? = 0 v (each input) ?5.0 ? a input common mode range v (sns+,sns?) =750 mv ?0.3 1.0 v current sense conversion (v dd = 5.0 v) d/a resolution referred to sns+, sns? inputs 4.70 4.92 5.20 mv full scale value referred to sns+, sns? inputs 575 625 675 mv differential non?linearity ? 0.75 lsb dac offset dac code = 0 ?5.0 ? 5.0 mv trip point accuracy dac code = 32 10 (25% fs) 12.5 ? 12.5 mv dac code = 66 10 (50% fs) 12.5 ? 12.5 mv dac code = 95 10 (75% fs) 12.5 ? 12.5 mv dac response delay (see figure 6) t dac ; csb rising to loop state change dac code = 127 10 (full scale) c gate = 2 nf (note 5) ? 500 ns
ncv7510 http://onsemi.com 9 electrical characteristics (continued) (5 v < vdrn < 26 v, 4.75 v < v dd < 5.25 v, ?40 c < t j < 125 c, unless otherwise specified.) (note 4 ) characteristic conditions min typ max unit overcurrent comparator input bias current v ocp = 3.0 v 0.26 3.0 a linear input voltage range 1.0 3.0 v mode select threshold v dd = 5.0 v 4.2 4.5 4.8 v internal overcurrent reference v ocp = v dd = 5.0 v 2.7 3.0 3.3 v detection blanking time (see figure 7) time to fault output low 1.25 2.5 5.0 s antisaturation detect gate mosfet auxiliary register bit 5 = 0, vdrn?v src auxiliary register bit 5 = 1, vdrn?v src 0.96 1.92 1.20 2.40 1.44 2.88 v v clamp mosfet auxiliary register bit 4 = 0, v src ?v pgnd auxiliary register bit 4 = 1, v src ?v pgnd 0.2 0.4 0.4 0.8 0.6 1.2 v v src input bias current v src = 14 v, v gate = 14 v v src = 0 v, v gate = 0 v ?10 0.44 4.0 a a detection blanking time (see figure 8) time to fault output low; gate or clamp 5.0 10 20 s serial peripheral interface (vdrn = 14 v, v dd = 5.0 v, c so = 200 pf) (figure 9) sclk clock period 250 ns maximum input capacitance sl, sclk; (note 5) 12 pf sclk high time f sclk = 4.0 mhz, sclk = 2.0 v to 2.0 v 125 ns sclk low time f sclk = 4.0 mhz. sclk = 0.8 v to 0.8 v 125 ns sl setup time sl = 0.8 v/2.0 v to sclk = 2.0 v f sclk = 4.0 mhz (note 5) 25 ns sl hold time sclk = 2.0 v to sl = 0.8 v/2.0 v f sclk = 4.0 mhz (note 5) 25 ns so rise time (10% v so to 90% v dd ) c so = 200 pf (note 5) 25 50 ns so fall time (90% v so to 10% v dd ) c so = 200 pf (note 5) 50 ns csb setup time csb = 0.8 v to sclk = 2.0 v (note 5) 60 ns csb hold time sclk = 0.8 v to csb = 2.0 v (note 5) 75 ns so delay time sclk = 0.8 v to so data valid f sclk = 4.0 mhz (note 5) 65 125 ns transfer delay time csb rising edge to next falling edge. (note 5) 1.0 s 4. designed to meet these characteristics over the stated voltage and temperature recommended operating ranges, though may not b e 100% parametrically tested in production. 5. guaranteed by design.
ncv7510 http://onsemi.com 10 timing waveforms 50% t loop(hl) sns+ loop v dac(fs) 50% dd t loop(lh) figure 3. loop output response delay 80% 20% 50% t p(lh) t p(hl) control gate 80% 20% 50% t dly(gr) sns+ gate v dac(fs) dd t dly(gf) figure 4. gate output delay 80% t hld sns+ gate v dac(fs) hi?z v pgnd control figure 5. gate output low hold time (gate switched by control or sns+) 50% t dac csb loop 50% si (dac code = sns+ figure 6. dac response delay t ocb gate & clamp 50% sns+ fault v ocp (reference only) figure 7. overcurrent detection blanking time t asb gate & clamp v drn 50% v pgnd src fault v (drn?src) v (src?pgnd) (gate mosfet) (clamp mosfet) (reference only) figure 8. antisaturation detection blanking time v v b v b v v b v dd v dd v dd v dac(fs) v dac(zero ) v dd v dd full scale or zero) (dac code = zero or full scale)
ncv7510 http://onsemi.com 11 csb setup csb sclk si so msb in lsb in msb out lsb out see note transfer delay 1 bits 14...1 bits 14...1 16 so delay si setup si hold csb hold so rise,fall 90% v dd 10% v dd note: not defined but usually msb of data just received. figure 9. spi timing
ncv7510 http://onsemi.com 12 basic operating description introduction the ncv7510 is designed for use as a predriver for solenoids or other inductive loads requiring a apeak and holdo function. it contains all the necessary circuitry for programming various attributes of the peak and hold events. these attributes include the current levels of the peak (or pull?in) event, the current levels of the hold event and the dwell time of the pull?in event (see figure 10 w aveforms). the attribute values are written into appropriate registers in the ncv7510 via a 16?bit spi interface. the peak and hold event is directly initiated and determined by the inputs to the ena and control pins. by applying a logic high level to these inputs, the user has precise control over how long the solenoid will be activated. the dwell time base for the pull?in event is provided to the ic's pclk input by the user, and may be programmed by a register bit to either be derived from a clock signal or be level controlled. when driven by a clock signal, the drive mode will automatically change from the peak to the hold event when the dwell time expires. when level controlled, the drive mode will change according to the logic state of the pclk input. bringing the ena or control input low before the dwell time expires will terminate the peak event and turn off the predrivers. figure 10 shows the general behavior of the ncv7510. programmable peak programmable hold programmable pull?in time control input solenoid current clamp predrive gate predrive dwell timer figure 10. idealized waveforms
ncv7510 http://onsemi.com 13 basic operating description (continued) hysteretic control the ncv7510 employs hysteretic control to achieve the programmed peak and hold currents. the ic measures the load current via an external sense resistor (see functional block diagram on page 2 and application diagram on page 3). this voltage is applied to a differential amplifier's sns+ and sns? inputs. the amplified signal is then compared to the programmed peak and hold reference levels generated from the 7?bit d/a converter. (refer to figure 11) during the peak event, the load current is compared to the programmed values in the peak high and peak low registers for the duration of the programmed dwell time. the hysteretic controller will switch between the programmed peak high and peak low values at a pwm rate determined by the load supply voltage, the load characteristics, the peak and valley current levels, and the response times of the ncv7510 and external mosfets. when the dwell time has been reached, the controller will select the programmed values in the hold high and hold low registers and the load current will then be compared to these values. the hysteretic pwm rate for the hold event is dependent on the same factors as the peak event. when the ena and control inputs are brought high, the dwell timer is initialized and the mosfet drive control circuit selects the gate predrive output, activating the high side mosfet and allowing current to increase in the load. when the peak high current level is reached, the mosfet drive control circuit will turn off the gate predrive and then turn on the clamp predrive. with the high side mosfet turned off, current in the load will begin to decrease. when the peak low current level is reached, the mosfet drive control circuit will turn off the clamp predrive and then turn on the gate predrive. the peak event may be terminated before the end of the programmed dwell time by bringing either the ena or control input low. otherwise, the peak high/low cycle repeats for the duration of the peak dwell time. once the peak dwell time has been reached, the hysteretic mux control circuit will switch from the peak high and peak low registers and now use the hold high and hold low registers. operation in this mode is quite the same as described above for the peak event, except that the programmed hold currents are now used to reduce power dissipation in the load. the complete peak and hold event is terminated when ena or control is brought low. 16?bit spi 7?bit peak high 7?bit peak low 7?bit hold high 7?bit hold low 7?bit auxiliary 8?bit dwell 7?bit dac registers down counter mux prescaler predriver 5?bit fault pclk r sns v bat v b sense amp overcurrent comparator peak/hold comparator r a r b v dd l v dd 3v ref ocp 4.5v ocp select 20 mux gate clamp c1 c2 c3 a1 figure 11. hysteretic mux control block diagram
ncv7510 http://onsemi.com 14 detailed operating description power up/down control the ncv7510 powerup control prevents spurious output operation by interlocking the v bat and v dd power supplies. at the system level, it is assumed that the v bat voltage is available before the v dd voltage. the power?on reset (por) interlock circuit derives an output disable signal from the v bat voltage at the drn input and causes the gate and clamp outputs to be kept at the pgnd potential. application of the v dd power supply allows the outputs to subsequently be enabled when the v dd voltage exceeds the por threshold. all internal registers are then initialized to their default states, fault data is cleared and the gate and clamp outputs are held low (external mosfet v gs approximately 0 v.) when the v dd voltage falls below the por threshold during power down, the gate and clamp outputs are driven and held low until v bat falls below about 1.2 volts. spi communication the ncv7510 is a 16?bit spi slave device. fault data is simultaneously sent from the device's so pin while command data is received at the si pin under synchronous control of the master's sclk signal. no parity or buffer under/over run detection circuitry is employed; therefore a valid csb frame must contain exactly 16 sclk cycles for each csb highlowhigh transition. the host initiates communication when the csb input is driven low. present fault data is latched in the device's spi shift register when csb goes low. fault data, sent msb first at the so output, changes on the falling edge of sclk and is guaranteed valid before the next rising edge of sclk. the data at the si input is received msb first and must be valid before the rising edge of sclk. the 16 bits received at the si input before csb is driven high will be translated as the current command. spi communication between the host and the ncv7510 may either be parallel via individual csb addressing or daisy?chained through other devices using a compatible spi protocol. command and register structure the 16?bit command data received by the ncv7510 is decoded into 8?bit address and 8?bit data words. the upper byte, beginning with the received msb, is bit?wise decoded to address one of six internal registers and the lower byte is decoded into program data for the addressed register. a dummy address ($00) can also be sent to retrieve fault data. note that the register addresses are not fully decoded. sending an address combining more than one address bit will result in the same data being sent to more than one register. bits a 7 and a 6 select internal test modes and should always be set to 0. figure 12 describes the general 16?bit spi word format and valid register addresses. each register is next described in detail. d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $01 aux d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $02 hdlo d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $04 hdhi d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $08 pklo d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $10 pkhi d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $20 dwell msb lsb a 7 a 6 a 5 a 4 a 3 a 2 a 1 a 0 d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 address data figure 12. 16?bit spi word format and valid register addresses auxiliary register [$01] the aux register is used to program several diagnostic features and the behavior of the dwell timer under control of the pclk input and the dwell timer register. this register is initialized to $00 at por. bit definitions are shown for this register in figure 13. d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $01 aux dwell time pre?scale pclk input mode clamp anti?sat threshold gate anti?sat threshold overvoltage enable figure 13. aux register bit definitions bit d 7 selects an internal test mode and should always be set to 0. bit d 6 controls interruption of load current by the overvoltage detection function. at por, the overvoltage interrupt function is disabled. programming d 6 =1 enables overvoltage interrupt and will cause the fault output to respond to an overvoltage event. overvoltage events are reported via the spi shift register regardless of the state of aux d 6 .
ncv7510 http://onsemi.com 15 detailed operating description (continued) bits d 5 and d 4 program the respective antisaturation detection thresholds for the gate (high side) and clamp mosfets. at por, the gate threshold is nominally set to 1.2 v and the clamp to 0.4 v. programming the respective bits to 1 nominally sets the gate threshold to 2.4 v and the clamp to 0.8 v. bit d 3 selects the functional mode for the pclk input. at por, d 3 =0 and the pclk input is configured to accept a clock signal as the time base for an internal programmable dwell timer. the dwell timer determines when to change modes from peak to hold. setting d 3 =1 configures the pclk input to accept a logic?level input which then directly controls the selection of the peak or hold mode. when d 3 =1, pclk=0 selects the peak mode and pclk=1 selects the hold mode. bits d 2 ?d 0 program the dwell timer prescaler to divide the incoming clock signal at the pclk input when aux bit d 3 =0. refer to the dwell timer register description for additional programming details. peak/hold dac registers [$10,$08,$04,$02] the peak and hold registers program the dac reference pairs for the peak and hold load currents. each 8?bit register uses only the 7 lower bits, and bit 8 must always be set to 0. at por, the registers are set to $00. the pkhi ($10) and pklo ($08) register pair contents are the dac reference values used during the peak mode of the control cycle. the hdhi ($04) and hdlo ($02) register pair contents are the dac reference values used during the hold mode of the control cycle. the peak or hold mode is determined by the state of the internal dwell timer or the logic level at the pclk input. refer to the aux register and dwell timer register descriptions for additional details. the register values for the load currents can be determined with the following equation: val 10 i l r sns 4.92 mv lsbs (eq. 1) where i l is the desired load current, r sns is the current sense resistor, and 4.92 mv is the nominal d/a resolution. the maximum value of load current that can be programmed for a given r sns resistor can be found by: i l(max) 625 mv r sns (eq. 2) where 625 mv is the nominal d/a full?scale value. dwell time register [$20] the 8?bit dwell timer register value determines when the programmed dac reference pairs change from the peak mode to the hold mode. dwell timer operation is also dependant upon the value of aux register bits d 3 ?d 0 (refer to the auxiliary register description.) figure 14 shows a detailed block diagram of the dwell timer. 8?bit down counter 20 3?bit prescale divider pclk peak dwell time (10 m s time base) $01 d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 $20 d 7 d 6 d 5 d 4 d 3 d 2 d 1 d 0 4?20mhz clock figure 14. dwell timer block diagram when aux d 3 =0, the dwell timer register value is combined with the aux d 2 ?d 0 prescale value to generate a dwell time based on the clock signal applied to the pclk input. the timer is designed to produce dwell times from 0 to 2.55 ms with 10 s resolution for popular host controller clock rates. figure 15 illustrates the prescale divisor truth table for some common clock rates. $01 d 7 d 3 d 2 d 1 d 0 d 6 d 5 d 4 0 0 0 0 2 0 0 0 1 3 0 0 1 0 4 0 0 1 1 5 0 1 0 0 6 0 1 0 1 7 0 1 1 0 8 0 1 1 1 10 1 x x x direct in pclk (mhz) 4.0 6.0 8.0 10.0 12.0 14.0 16.0 20.0 logic level figure 15. aux register prescale divisors a general formula for determining dwell time based on the clock frequency applied to the pclk input is: t dwell ( div 20 n 10 ) 20 pclk (eq. 3) where t dwell is the dwell time in s, div is the pre?scale divisor, pclk is the clock frequency in mhz, and n 10 is the content of the dwell time register. fault reporting when a fault occurs, the open?drain fault flag is latched low and fault information is latched and transferred into the spi shift register while csb is high. the host controller initiates spi communication when csb goes low, and current fault information can then be shifted out of the ncv7510's so output. while csb is low, transfer of new fault information is blocked. the fault flag and fault data are cleared by the rising edge of csb.
ncv7510 http://onsemi.com 16 detailed operating description (continued) bits d 4 ?d 0 of the 16?bit so word indicate detected faults such that d x = 1 when a fault is detected. figure 16 describes the fault bit definitions. at por, the register bits are cleared to $00. refer to the fault diagnosis description for details regarding the ncv7510's fault strategies and behaviors, discussed in the next section. d 4 d 3 d 2 d 1 d 0 so fault data overvoltage short to gnd short to battery open load overcurrent d 15 ? d 5 = don't care; d 4 ? d 0 : 1 = fault, 0 = no fault figure 16. so fault bit definitions fault diagnosis and protection behavior general the ncv7510 continuously monitors the load supply voltage, external mosfets, the load current, and the control loop state during a control cycle for fault conditions. faults are managed on a cycle?by?cycle basis with regard to the control and ena inputs and are recoverable (automatic fault re?try) such that the ncv7510 will attempt to properly drive the load during the next control cycle. attention is focused on faults that may cause destructive failure of the load, the external mosfets, or the sense resistor. overcurrent faults are detectable regardless of the control and ena input states. short to battery and short to gnd (antisaturation) faults are detectable when the control and ena inputs are high. destructive fault types are managed when possible to prevent failure by latching both predriver outputs off. fault reporting for these types is priority encoded such that the first detected fault locks out subsequent fault reporting bits. these faults cause the fault flag to be set and latched low. non?destructive open load faults require no intervention and are detectable at the end of a control cycle when control or ena goes low. this fault type has no priority and is reported if no other fault has been detected, and does not set the fault flag. overvoltage faults are detected without regard to the control and ena inputs. management, reporting and fault flag behavior for this fault type is dependent upon the state of aux register bit d 6 . reset of fault protection, and clearing of fault data and the fault flag are independent. protection circuitry is reset on the rising edge of either the control or ena inputs. fault data and the fault flag are cleared by the rising edge of csb. at power?on reset, all fault protection, fault data, and the fault flag are cleared. fault detection, protection and reporting are detailed in the following sections and are summarized in table 1. overvoltage the load supply voltage is monitored at the drn pin for overvoltage faults, and fault detection occurs regardless of the states of control and ena inputs. the interruption of load current by the overvoltage detection circuit can be programmed by bit d 6 in the aux register. at por, the overvoltage interrupt default state is disabled (aux d 6 =0). when aux d 6 =0 an overvoltage fault has no priority and is reported if no other fault has been detected. the predrivers and the fault flag are unaffected. programming aux d 6 =1 enables overvoltage interrupt. when control and ena are high, an overvoltage fault will cause the gate output to be latched off, the clamp output to be latched on, and the fault flag to be latched low. the fault is given reporting priority and locks out subsequent fault reporting bits. overvoltage protection is reset when control or ena is brought low and then high again. avalanche of the high side (hs) mosfet may occur when the clamp mosfet is on during an overvoltage fault (overvoltage enabled.) avalanche of both the hs and clamp mosfets may occur (overvoltage disabled) if the overvoltage amplitude exceeds the combined avalanche voltages of both mosfets. the devices should be carefully chosen for proper avalanche voltage and avalanche energy rating suitable to the application and its operating environment. note that the ncv7510 requires transient overvoltage suppression in accordance with the specifications in the maximum ratings table. overcurrent load current (converted to a voltage by external sense resistor r sns ) is monitored at the sns+ and sns? differential inputs. a fault is detected when the amplified differential voltage exceeds the overcurrent reference. a nominal 2.5 s filter is used to help prevent false overcurrent detection. overcurrent detection occurs regardless of the states of the control and ena inputs. this fault has reporting priority and will latch the fault flag low. if overcurrent is detected when control and ena are high, both gate and clamp outputs are latched off. overcurrent protection is reset when the control or ena input is brought low and then high again.
ncv7510 http://onsemi.com 17 detailed operating description (continued) an overcurrent comparator input pin (ocp) is provided to program a current limit reference value. when the voltage at the ocp input is less than 4.5 v, the applied voltage is the overcurrent reference voltage. when the voltage is greater than 4.5 v, an internal 3.0 v overcurrent reference is used. the voltage at ocp pin must not exceed v dd . applying approximately v dd + 1.4 v will place the ncv7510 in test mode and suspend normal operation. the user is advised to avoid activating the test mode. the ocp reference can be programmed via an external voltage divider placed between the v dd and dgnd pins, as illustrated by resistors r a and r b in the hysteretic mux block and application diagrams. the following formulas can be used to dimension the resistors: r a r b v dd i oc 4 r sns 1 (eq. 4) i oc r b r a r b v dd 4 r sns (eq. 5) where 4 is the nominal sense amplifier gain and r sns is the external load current sense resistor. overcurrent faults may be detected when the load is shorted, when the sns+ input is shorted to v bat , when the sense resistor is open, or when the peak or hold currents are programmed higher than the overcurrent reference. open?circuit failure of the sense resistor may produce voltages in excess of the ncv7510's sns+ input maximum rating. this condition can be avoided by series connection of a pair of diodes across the sense resistor (see application diagram d5, d6) to provide a path for the load cu rrent. the diodes must be capable of carrying the maximum expected load current and should be energy?rated for the application. open load to maintain the scalable flexibility of the ncv7510, the states of the clamp predriver output and the ena and control inputs are monitored to determine an open load condition as opposed to the detection of an absolute value of minimum load current. it is expected that during normal operation, a state change will occur at the clamp output as a result of load current modulation between the peak high and peak low program points while ena and control are high. open load detection relies on the occurrence of a control loop state change before the ena or control input goes low. if a control loop state change has not occurred during the time that ena and control were high, an open load fault is detected. when an open load fault is detected, no intervention is required. this fault type has no priority and is reported if no other fault has been detected, and does not set the fault flag. open load fault data is cleared by the rising edge of csb. open load faults may be detected when the load is open, when the sense resistor is shorted, or when the load current is unable to reach the programmed peak or hold high current value. false open load faults may be indicated during engine cranking when battery voltage can initially dip to about 5?6 volts. the programmed current may not be reached and a state change in the control loop may not occur, thus producing a false open load indication. antisaturation each of the high side and clamp mosfet's drain?to?source voltages is separately monitored and compared to an independently programmable saturation detection threshold voltage. the detection thresholds are programmed via the aux d 5 and d 4 register bits. at por, the thresholds default nominally to 1.2 v for the high side mosfet and to 0.4 v for the clamp mosfet. setting aux d 5 =1 programs the high side antisaturation detection threshold to nominally 2.4 v. similarly, setting aux d 4 =1 programs the clamp antisaturation detection threshold to nominally 0.8 v. each of the antisaturation detectors employs a nominal 10 s filter to help prevent false anti?sat fault detection. when control and ena are high, the antisaturation circuitry monitors the voltage between the drn and src pins (high side) if the gate output is on and monitors the voltage between the src and pgnd pins if the clamp output is on. high side saturation may be detected when a short to ground fault at the src pin exists. clamp saturation may be detected when a short to battery fault at the src pin exists. the gate and clamp outputs are latched off and the fault flag is set if either of these faults is detected. fault reporting for these types is priority encoded such that the first detected fault locks out subsequent fault reporting bits. antisaturation protection is reset when the control or ena input is brought low and then high again.
ncv7510 http://onsemi.com 18 detailed operating description (continued) table 1. fault types, management and reporting fault type input states 2output states 3fault data 3fault flag set note control ena aux d 6 gate clamp report bit priority flag set overcurrent x x x off off d0 yes yes open load h l 1 x off off d1 no no 1 short to bat 1 1 x off off d2 yes yes 2 short to gnd 1 1 x off off d3 yes yes 3 overvoltage x x 0 e e d4 no no 4 0 1 1 off off yes yes 1 1 1 off on yes yes 2output states after detection of a fault. protection is reset on the rising edge of the control or ena inputs. 3 fault data and the flag are cleared by the rising edge of the csb input. 1. if detected, fault is reported after the falling edge of the control (or ena) input. 2. detection via clamp antisaturation. 3. detection via gate antisaturation. 4. when aux d 6 = 0, overvoltage will be reported along with priority faults; outputs are unchanged.
ncv7510 http://onsemi.com 19 detailed operating description (continued) operational behavior general the ncv7510 is designed to maintain the programmed load current at the pkhi and pklo or at the hdhi and hdlo reference values. while the device's flexibility allows all of these to be programmed to the same value, a non?zero value is nonetheless required and the minimum value is constrained by the ncv7510's dc and ac capabilities. it is also possible to reverse the order of the pkhi|pklo and hdhi|hdlo register values such that the hi value is less than the lo value. while this is unlikely to result in damage to the application, it will certainly lead to bizarre behavior. as previously noted, the pkhi program value may not be reached during engine cranking when battery voltage may initially dip to about 5?6 volts, particularly when driving low resistance loads. this has additional implications for both the external bootstrap circuitry (duty cycle 100%) and open?load detection behavior, both of which are discussed in other sections of this data sheet. the ncv7510's ability to maintain the programmed load currents is constrained by the total of the ncv7510's inherent dc accuracy and loop response delay, the load characteristics, and any additional delays imposed by external compensation circuitry, whether slew?rate limiting or other filtering designed to attenuate the egress or ingress of radiated or conducted emi. mode control the dwell timer selects which pair of the peak or hold registers is setting the internal dac and thus determines whether the device is operating in the peak mode or the hold mode. bit d 3 of the aux register determines whether a logic level at the pclk input directly controls the dwell time or whether the internal dwell timer divides down an external clock signal at the pclk input. when aux d 3 =1, the control loop will be placed in the peak mode when pclk=0 and in the hold mode when pclk=1. when aux d 3 =0, the control loop state will be determined by the state of the dwell timer. the dwell time is programmed via prescale divisor aux register bits d 2 ?d 0 and by the 8?bit dwell timer register. in the following sections, adwell timero means either the state of the logic level at the pclk input or the state of the internal dwell timer. output control the state of the gate and clamp outputs is determined by the ena and control inputs and by the state of the control loop. in the absence of any faults, the state of the control loop is determined by the contents of the peak and hold registers, the state of the dwell timer, and the magnitude of the load current. the output control cycle begins when both the ena and control logic inputs are asserted high and ends when either input is asserted low. at the beginning of each control cycle the dwell timer and protection circuitry are initialized, and the internal dac is initialized to the pkhi register value (if the dwell time register content is non?zero or if aux d 3 =1 and pclk=0) or to the hdhi register value (if the dwell time register content is null or if aux d 3 =1 and pclk=1). the gate and clamp output states will be determined by the state of the control loop. at the end of each control cycle the gate and clamp outputs are driven low, the dwell timer is reset, and open load fault data is transferred into the spi shift register if an open load fault exists. control loop load current is converted to a voltage via an external sense resistor and compared with the programmed internal dac voltages. during the dwell time, the load current is compared to the dac voltages set by the peak high and peak low register values. when the dwell time expires, the load current is compared to the dac voltages set by the hold high and hold low register values. the state of the control loop is reflected at the loop output such that a logic low indicates that load current is less than the programmed dac reference. when the load current is less than the peak or hold high current, the gate output is at the v b potential and the clamp output is at pgnd. when the load current is greater than the peak or hold hi current, the dac voltage is set to the peak or hold low register value, the gate output is driven to pgnd and the clamp output is driven to v dd . when the load current is less than the peak or hold low current, the dac voltage is set to the peak or hold high register value, the gate output is driven to v b and the clamp output is driven to pgnd.
ncv7510 http://onsemi.com 20 detailed operating description (continued) mosfet predrivers the ncv7510 employs cross?conduction suppression for the external high side and clamp mosfets. the clamp antisaturation circuitry is used to detect the turn?off of the high side mosfet and the voltage at the clamp pin is monitored to detect turn?off of the clamp mosfet. figure 17 shows the simplified predriver circuits. the high side predriver is designed to allow external system level diagnostics to be implemented at the src pin. the driver is constructed to provide a typical 20 discharge path for 10 s at turn?off and a 60 k gate?source bleed resistance to help prevent mosfet turn?on from leakage or noise. the r g resistor must be carefully chosen to ensure full depletion of the high side mosfet's gate charge in less than 10 s. current for the gate predrive output is supplied from the v b voltage developed by an external bootstrap circuit or boost power supply. current for the clamp predrive output is supplied from the v dd power supply. while the ic contains no slew rate control circuitry, slew rate control of the high side mosfet can be achieved by the use of a series gate resistor (r g .) since the body diode of the clamp mosfet conducts the load current immediately after high side turn off, slew rate control of the clamp mosfet gives no benefit and the use of a series gate resistor will interfere with cross?conduction suppression. bootstrap circuit a bootstrap circuit can be constructed using a diode, resistor, and capacitor to generate the v b voltage necessary to put the external high side mosfet in full conduction (refer to figure 17). the circuit charges c boot through d2 and r lim when the src pin is low. the charge is then transferred to the high side mosfet when m1 in the gate predriver is turned on, and the capacitor rides up with the voltage at the src pin. the charge is continually refreshed as a result of alternate switching of the high side and clamp mosfets. a clamp diode at the v b input (see application diagram diode d3) may be needed to keep the ncv7510 within its maximum ratings during overvoltage transients. d4 ensures that the high side mosfet's maximum v gs is not exceeded (refer to figure 17). while simple and straightforward in operation, a bootstrap circuit depends on periodic refresh and thus cannot run at 100% duty cycle. during engine cranking, the pkhi program value may not be reached and a state change in the control loop may not occur, possibly fully depleting (and preventing recharge) of the bootstrap capacitor. with the use of logic?level mosfets and careful design, sufficient v gs should be available during start up. attention to leakage paths (such as external gate?source bleed resistors) and the v b input bias current will help ensure that gate charge is available when recharge does not occur. m1 20 m2 20 gate m3 60 k i vb in src r g c boot r lim d2 m4 20 m5 20 200 k clamp q vbat pgnd r sol l sol r sns m hs m cl figure 17. simplified gate and clamp predrivers 10 s v dd v b d4
ncv7510 http://onsemi.com 21 package dimensions so?20l dw suffix case 751d?05 issue g 20 1 11 10 b 20x h 10x c l 18x a1 a seating plane h x 45 e d m 0.25 m b m 0.25 s a s b t e t b a dim min max millimeters a 2.35 2.65 a1 0.10 0.25 b 0.35 0.49 c 0.23 0.32 d 12.65 12.95 e 7.40 7.60 e 1.27 bsc h 10.05 10.55 h 0.25 0.75 l 0.50 0.90 0 7 notes: 1. dimensions are in millimeters. 2. interpret dimensions and tolerances per asme y14.5m, 1994. 3. dimensions d and e do not include mold protrusion. 4. maximum mold protrusion 0.15 per side. 5. dimension b does not include dambar protrusion. allowable protrusion shall be 0.13 total in excess of b dimension at maximum material condition.
ncv7510 http://onsemi.com 22 on semiconductor and are registered trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to mak e changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for an y particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including wi thout limitation special, consequential or incidental damages. atypicalo parameters which may be provided in scillc data sheets and/or specifications can and do vary in different application s and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the scillc product could create a sit uation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, af filiates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, direct ly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyright laws and is not for resale in any manner. publication ordering information n. american technical support : 800?282?9855 toll free usa/canada japan : on semiconductor, japan customer focus center 2?9?1 kamimeguro, meguro?ku, tokyo, japan 153?0051 phone : 81?3?5773?3850 ncv7510/d flexmos is a trademark of semiconductor components industries, llc. literature fulfillment : literature distribution center for on semiconductor p.o. box 61312, phoenix, arizona 85082?1312 usa phone : 480?829?7710 or 800?344?3860 toll free usa/canada fax : 480?829?7709 or 800?344?3867 toll free usa/canada email : orderlit@onsemi.com on semiconductor website : http://onsemi.com order literature : http://www.onsemi.com/litorder for additional information, please contact your local sales representative.

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