|
If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
Datasheet File OCR Text: |
zxbm1021 document number: ds draft rev. 1 1 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 single phase variable speed motor control pre-driver description the zxbm1021 is a high performance, low noise, single-phase, direct current brushless (bldc) motor pre-driver with variable pwm speed control and current control suitable for fan and blower motors. for system flexibility the motor speed can be controlled by either an external pwm control signal or by a dc voltage signal from an external control voltage or from a thermistor network. to prevent motor inrush current the device has a soft start feature. to help protect the motor coil, the zxbm1021 provides rotor lock protection which shuts down the output drive if rotor lock is detected. the device automatically re-starts with soft-start when the rotor lock is removed. the zxbm1021 monitors the motor current to provide a programmable over current limit. a tachometer output is provided by the open collector output frequency generator (fg) pin which allows external interface to monitor motor rotation or speed. the fg output is the magnetic change frequency. the zxbm1021 is available in space saving and low profile u-qfn4040-20 package. features ? operating voltage: 6.8v to 18v o can be extended with external regulator ? speed control via external pw m, dc or thermistor signals ? low noise, high efficiency ? soft start ? integrated current control ? reference voltage output ? built-in hall amplifier for direct connection of hall element ? rotor lock protection o lock detection, output shutdown and automatic re-start ? minimum speed setting ? frequency generator (fg) output ? thermally enhanced space saving low profile u-qfn4040-20 package ? totally lead-free & fully rohs compliant (notes 1 & 2) ? halogen and antimony free. ?green? device (note 3) pin assignments (top view) u-qfn4040-20 applications ? personal, servers and mainframe computers cooling fans ? instrumentation and equipment cooling fans ? home appliance fans and blowers ? central heating blowers and extraction systems ? industrial fans, blower and extractors ? hand dryers ? hand-held power tools ? pumps notes: 1. no purposely added lead. fully eu directiv e 2002/95/ec (rohs) & 2011/6 5/eu (rohs 2) compliant. 2. see http://www.diodes.com for more in formation about diodes incorpor ated?s definitions of halogen- and antimony-free, "gree n" and lead-free. 3. halogen- and antimony-free "green? products are defined as those which contain <900ppm br omine, <900ppm chlorine (<1500ppm t otal br + cl) and <1000ppm antimony compounds.
zxbm1021 document number: ds draft rev. 1 2 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 typical applications circuit (note 4) notes: 4. fg pull-up resistor is not shown in the typical application circuit. generally, the fg pull-up resistor is located at the system host end rather than the fan motor pcb. zxbm1021 document number: ds draft rev. 1 3 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 pin descriptions package types: qfn4040-20 pin number pin name description 1 hbias hall bias supply voltage output pin. output voltage is 1.75v typical to supply the external un-buffered (?naked?) hall element. a resistance can be added in series with hall element if lower bias voltage is needed. 2 thref 5v reference voltage output pin. this voltage is used to supply the external networks. 3 pwmspd speed control pwm signal input pin. pwm signal should be between 0% to 100% duty ratio. 4 spd dc voltage speed control input pin. the control signal voltage should be between 3v for 0% (stop) to 1v for 100% (full speed) speed control. in dc voltage mo de, connect a capacitor between spd and ground. 5 c spd output pin of the pwm speed control input signal in tegrator. in pwm speed control mode, connect a 0.1 ? f capacitor from c spd pin to ground and connect c spd pin to spd pin. in dc voltage speed control mode, leave this pin unconnected. 6 s min minimum speed setting pin. voltage between 3v to 1v on this pin sets the minimum speed the motor is run at between 0% to full speed. the lowest mini mum speed achieved depends on the motor coil design. 7 c lck rotor lock detect, auto restart timing and soft-start timing control pin. typically a 470nf capacitor is connected to this pin to set the soft-start (to full speed), lock detect and restart timings. 8 gnd supply return ground pin 9 fg frequency generator output to provide a tachometer signal. this is a buffered output from the hall amplifier. 10 setth current sense threshold setting pin. used to set the th reshold voltage that represents the maximum current to be taken by the motor. the current sense volt age at sense pin is compared to the setth voltage. 11 sense current sense pin. input for the signal from a sense resi stor in the ground return of the h-bridge circuit to represent the current taken by the motor. 12 setthref a variable voltage source used to set the voltage on the setth pin. 13 ph1hi phase 1 high-side external power switch driv e output pin. this is a 50ma open-collector output. 14 ph2hi phase 2 high-side external power switch driv e output pin. this is a 50ma open-collector output. 15 ph2lo phase-2 low-side external power switch drive output pi n. darlington emitter follower output with active pull down to give source/sink current of 100ma/100ma. 16 ph1lo phase-1 low-side external power switch drive output pi n. darlington emitter follower output with active pull down to give source/sink current of 100ma/100ma. 17 v+op phase low output supply pin. only the low side ou tput drives for ph1lo and ph2lo are supplied by the v+op pin. for external mosfet power devices, a resistor from v cc pin to v+op slows down the turn-on speed of the low-side mosfet s and therefore helps prevent shoot-through during turn-on of low-side switches. for external bipolar powe r devices, a resistor between the v cc pin and v+op controls the current into the transistor base. 18 v cc power supply pin 19 h+ hall device positive input pin. when h+ is higher in relation to h-, ph2 is active. 20 h- hall device negative input pin zxbm1021 document number: ds draft rev. 1 4 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 functional block diagram notes: 5. the zxbm1021 has an open-collector fg. typically a pull-up resistor of 10k ? is recommended from fg pin to the supply voltage. zxbm1021 document number: ds draft rev. 1 5 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 absolute maximum ratings (note 6) @t a = +25c, unless otherwise specified.) symbol characteristics values unit v ccmax supply voltage (note 7) -0.6 to 20 v i ccmax ic input current 200 ma p dmax power dissipation (see thermal de-rating curve on ?thermal performance? section) u-qfn4040-20 820 mw t st storage temperature range -55 to 150 o c t j maximum junction temperature 150 ? c esd hbm human body model (hbm) esd capability 2 kv esd mm machine model (mm) esd protection 300 v notes: 6. stresses greater than the 'absolute maximum ratings' specified above may cause permanent damage to the device. these are stress ratings only; functional operation of the device at these or any other conditions exceeding those indicated in this specification is not implied. device reliability may be affected by exposure to absolu te maximum rating conditions for extended periods of time. 7. the absolute maximum v cc of 20v is a transient stress rating and is not meant as a functional operating condition. it is not recommended to operate the device at the absolute maximum rated conditions for any period of time. recommended operating conditions symbol characteristic conditions min max unit v cc supply voltage operating, -40 o c to 110 o c 6.8 18.0 v t a operating temperature range operating -40 110 o c electrical characteristics (@t a = +25c, v dd = 12v, unless otherwise specified.) symbol characteristics conditions min typ max unit i cc supply current no load (note 8) - 10 15 ma h all connections vin hall amplifier input voltage diff peak to peak 40 mv v cm hall amplifier common mode voltage 0.5 v thref v v hys hall amplifier input hysteresis 12 mv i bs hall amplifier bias current 700 1000 na v hb hall bias voltage i hb = 10ma 1.5 1.75 1.95 v i hb hall bias output current capability 10 ma r eference voltage v thref thref reference output voltage i othref = 10ma, +25 o c 4.85 5 5.15 v i othref = 10ma, -40 o c to +110 o c 4.75 5 5.25 v i othref thref output current capability 10 ma p wm oscillator f pwm pwm frequency 18 25 khz d c voltage speed control v spdl spd voltage minimum 100% pwm drive 1 v v spdh spd voltage maximum 0% pwm drive 3 v i spd spd pin current at speed demand of 50% of the full speed and without minimum speed setting v spd = 2v s min = 0v 0.5 2 a i spd_smin2v spd pin current with minimum speed setting of 50% of the full speed v spd = 3v rspd =10k ? s min = 2v 100 a lin spd spd pin voltage to output pwm linearity v spd = 2v 3 % notes: 8. measured with pins h+, h-, c lck and c pwm and all other signal pins open circuit zxbm1021 document number: ds draft rev. 1 6 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 electrical characteris tics (continued) (@t a = +25c, v dd = 12v, unless otherwise specified.) symbol characteristics conditions min typ max unit pwm speed control v pwmspdh pwmspd high level 2 v cc v v pwmspdl pwmspd low level 0.4 v i pwmspd pwmspd high level input current 0.8 2 a d pwmspd pwm speed signal duty range 0 100 % f pwm_max maximum frequency of pwm control signal 100 khz lin int pwmspd pin pwm duty ratio to c spd output voltage linearity pwmspd duty ratio 50%, pwm frequency f pwm = 25khz 1.94 2 2.06 v minimum speed setting i smin s min input current v smin = 2v -0.25 -0.5 a soft start tss soft-start time to full speed c lck = 0.47 ? f 3 s lock timing lock condition t lckdet : t off ratio 1:8 i lckcl c lck charge current ? soft start (from lock) and in lock mode lock mode, v clck = 2.5v 0.45 0.7 1.07 a i lckcr c lck charge current ? run run mode 3.25 5.5 9.0 a i lckdl c lck discharge current - lock lock mode, v clck = 2.5v 0.45 0.7 1.07 a v clckthh c lck high threshold voltage 5 v v clckthl c lck low threshold voltage lock mode 0.6 v current limit v setthref setthref output voltage i setthref = 200ua thref- 0.17 thref- 0.1v thref- 0.05 v i setthref setthref output current -200 a i sense sense input current -20 -100 na i setth setth input current -20 -100 na output drives v oh ph1lo and ph2lo output high voltage i oh = 100ma v cc - 2.2 v cc - 1.7 v v ola ph1lo and ph2lo output low voltage i ol =100ma (note 9) 0.3 0.5 v v olb ph1lo and ph2lo output low voltage i oh = 50ua (note 10) 0.3 0.5 v i oh ph1lo and ph2lo output source current 100 ma i ol ph1lo and ph2lo output sink current 100 ma v ola ph1hi and ph2hi output low voltage i oh =50ma (note 10) 0.3 0.5 v i ol ph1hi and ph2hi output sink current 50 ma i off ph1hi and ph2hi off output leakage current 100 na t cd commutation delay 20 70 s output flags i fgol fg low level output current capability 10 ma v fgol fg low level output voltage i fgol = 10ma 0.4 v lock conditions t lckdet lock detect time (time it waits for before next hall signal before deciding to turn outputs off for fixed time) c lck =0.47 ? f i lckcr = 5.5ua 400 ms t off output off time after lock is detected. c lck =0.47 ? f 3 s notes: 9. measured when opposing phase output is low 10. measured when opposing phase output is high zxbm1021 document number: ds draft rev. 1 7 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 functional descriptions h-bias ? hall bias output this is a 1.75v nominal voltage source to bias a differential un-buffered hall elemen t sensor. if a hall element requires a low er voltage than the h-bias output, connect an appropriate value resistor bet ween the h-bias pin and the hall element supply pin. h+ and h- ? hall inputs the rotor position is detected by a hall sensor, with the output applied to the h+ and h-pins. th is sensor can be either a 4 pi n 'naked' hall device or of the 3 pin buffered switching type. for a 4 pin device t he differential hall output signal is connected to the h+ and h- p ins. for a buffered hall sensor the hall device output is attached to the h+ pin, with a pull-up attached if needed, whilst the h- pin has an external p otential divider attached to hold the pin at half v thref . when h+ is high in relation to h-, ph2 is the active drive. thref ? output reference voltage this is a 5v nominal reference output volt age. it is designed to 'source' current and therefore it will not 'sink' any current from a higher voltage. the total current drawn from the thref pin by any external circuitry, such as the minimu m speed potential divider to s min pin, should not exceed 10ma. spd ?speed control dc voltage input the voltage applied to the spd pin provides control over the f an motor speed by varying the pulse width modulated (pwm) drive r atio at the ph1lo and ph2lo outputs. the control signal takes the form of a variable dc voltage input of range 3v to 1v, representing 0% to 100% drive respectively. if variable speed control is not required th is pin can be tied to an external potentia l divider to set a fixed speed or tied to ground to provide full speed i.e. 100% pwm drive. if required this pin can also be used as an enable pin. the application of a voltage >3 .0v on this pin will force the pwm drive fully off, in effect disabling the drive, providing the mini mum speed function is not active (see s min pin section below). to use a minimum speed setting or current control in dc voltage speed control mode, add a series resistor 10k ? or greater (r11 in typical application circuit for dc control in page 2) between speed control dc voltage input source and spd pin. pwmspd ? speed control pwm signal input the duty ratio of the speed control pwm signal input to this pin controls the fan motor speed by varying the output drive pwm r atio at the ph1lo and ph2lo outputs. in the pwm speed control mode, the pwmspd pin and the c spd pin work together to the control the speed. the pwm signal input on the pwmspd pin is in tegrated by the capacitor on the c spd pin (see c spd pin description). pwm control input signal to the pwmspd pin needs to be a ttl logic levels. c spd ? pwm speed control signal integrator output when pwm input signal is used to control t he motor speed, pwm signal is integrated to dc voltage between 1v to 3v to for speed control. if pwmspd pin input is ttl low, the output voltage on c spd is 3v and if pwmspd pin is ttl high, the c spd pin output is at 1v. in order for the integrator function to be fulfilled an external capacitor is required. this would normally be a 0.1 ? f capacitor for a 25khz input pwm frequency applied to the pwmspd input. in pwm speed control mode, connect 0.1 ? f capacitor from c spd pin to ground and connect c spd pin to spd pin. when in dc voltage speed control mode keep pwmspd and c spd pins unconnected. s min ? minimum speed setting a voltage can be set on this pin via a potential divider between the thref and gnd pins. this voltage is monitored by the spd p in to clamp the spd control voltage so that it does not rise above s min voltage. as a higher voltage on the spd pin represents a lower speed, the s min setting prevents the motor speed going lower than the minimum speed set by the s min pin. if this feature is not requir ed the pin is left tied to thref so no minimum speed will be set. if the fan is being controlled from an external voltage source onto the spd pin then either this feature should not be used or if the minimum speed setting is required then a 10k ? or greater resistor should be plac ed in series with the spd pin. zxbm1021 document number: ds draft rev. 1 8 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 functional descriptions (continued) c lck ? locked rotor timing capacitor the c lck pin will have a capacitor connected to ground. it is a multi-f unction pin providing timing for the lock detect, auto-restart a nd soft-start conditions. different rates of charge and discharge of c lck capacitor depending on the mode of operation (fan operation status) give the soft-start (t ss ) to full speed, lock-detect time (t lckdet ) and lock time (t off ) before next auto-start retry. when t he motor is running, the capacitor is discharged at every hall signal change. c lck pin provides the timing for the locked rotor monitor. in norma l operation, and after the soft-start period, lock detect is ena bled. if the hall signal does not change (i.e. a rotor lock condi tion) within the lock detect time (t lckdet ), the outputs are disabled. in this condition the motor will not be driven for a set time t off. this t off time depends on the external c lck capacitor value and its internal discharge current (i lckdl ). after the t off period device goes into a soft-start period (t ss ) to re-start the motor. if the motor has not turned to generate a transition on the hall inputs by the end of this period, motor re-enters motor lock t off period with outputs disabled. once the fan is running normally at the end of a soft-start period, the motor is deemed as runni ng and goes into lock-detection mode. the time periods of t ss , t lckdet and t off are determined by the value of the external capacitor on the c lck pin and the internal charge and discharge currents during these time periods. the currents during t ss , t lckdet and t off are i lckcl , i lckcr and i lckdl respectively. during soft-start mode, the setthref voltage is increased from 0 to vref. a potential divider from setthref is used to generate setth voltage for current limit. as setthref ramps to nominal value, current limit set also ramps from 0 to nominal setting. this gradual release of current limit to full speed level provides the soft-start. fg ? frequency generator (tachometer) output this is the frequency generator output and is a buffered signal from the hall sensor. this is an open collector drive giving an active pull down with the high level being provided by an external pull up resistor. fg timing diagram zxbm1021 document number: ds draft rev. 1 9 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 functional descriptions (continued) sense ? current control sense this pin is used by the current sensing ci rcuit to monitor the current taken by the motor windings. the signal comes from a sen se resistor in the low-side ground return of the external h-bridge driver. setth ? current control threshold voltage this pin is used by the current sensing circuit as the reference voltage for the vo ltage on the sense pin to be compared agains t. if the voltage on the sense pin starts to exceed the voltage set on this pin the cu rrent control circuitry starts to back off the output drive pw m duty and thus reducing the current being supplied to the motor coil. setthref ? setth and start-up reference this pin is derived from an internal star t-up circuit and is used as the source volt age for the potential divider network attac hed to the setth pin. under running conditions this voltage will be typically thref-0.1v. however, during start up the voltage ramps up from 0v to th ref-0.1v at a rate determined by the capacitor on the c lck pin giving a gradual release of current limit from 0 to nominal setting. thref-0.1v is equal to 4.9v typical. this low power pin is capable of supplying a maximum of 200a. it should only be used to supply the potential divider network a ttached to the setth pin. ph1lo and ph2lo ? low-side external h-bridge drive output ph1lo and ph2lo outputs drive the low side of the external power dev ice h-bridge that in turn drives the single phase winding. these outputs provide both the commutation and pwm waveforms. the outputs are ac tive pull-up and active pull-down to help faster switching of f when driving mosfet devices with a high gate capacitance. when in the high state the outputs will provide up to 100ma of drive into the base or gates of external transistors as shown in the typica l application circuit shown on the front page. when in the low state the active phase driv e is again capable of sinking up to 100ma to aid turn off times during pwm operation . when the phase is inactive the output is held low by a 7.5k ? internal pull-down resistor. ph1hi and ph2hi ? high-side external h-bridge driver ph1hi and ph2hi are the high side outputs to the external h-br idge and are open collector outputs capable of sinking 50ma. this signal provides commutation only to the h-bridge. v+op ? phase outputs supply voltage this pin is the supply to the phase outputs ph1lo and ph2lo only. t his pin can be connected to v cc pin directly or through a resistor. for external bipolar power devices t he resistor on v+op is used to control the current into the transistor base and its va lue is chosen accordingly. for external mosfet power devices, the pin can be used to slow down the turn-on speed of the low-side mosfets. slowing down the turn-on speed of low side switches helps to prevent parasitic turn-on of the high-side switc hes and thus helping to prevent shoot-throu gh during turn-on of low-side switches. the gate resistor connected at ph1lo and ph2lo plus the resistor on v+op c ontrols the turn on speed of th e mosfet. the turn-off of speed of the mosfets is controlled by the gate resistor only. v cc ? ic supply voltage this provides the supply for th e device's internal circuitry except ph1lo and ph2lo output stages, which are supplied from the v+op pin. for 12v fans this can be supplied directly from the fan motor s upply. for fans likely to run in excess of the 18v maximum ratin g for the device this will be supplied from an external regulator su ch as a zener diode or low drop out regulator. gnd ? supply return this is the device supply ground return pin and will generally be the most negative supply pin to the fan. zxbm1021 document number: ds draft rev. 1 10 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 typical operating characteristics 4.50 4.60 4.70 4.80 4.90 5.00 5.10 5.20 5.30 5.40 5.50 -50-25 0 255075100125 thref (v) ambient operating temperature t a (c) thref vs ambient temperature 6v8 12v 18v 0 10 20 30 40 50 60 70 80 90 100 0 102030405060708090100 phlo duty cycle (%) speed control pwm signal (pwmspd) duty cycle (%) phlo output duty cycle vs. speed control pwm signal (pwmspd) duty cycle 0 10 20 30 40 50 60 70 80 90 100 0.9 1.1 1.2 1.4 1.5 1.7 1.8 2.0 2.1 2.3 2.4 2.6 2.7 2.9 3.0 3.2 duty cycle (%) speed control dc voltage spd (v) phlo output duty cycle vs speed control dc voltage (spd) 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 0 102030405060708090100 cspd voltage (v) speed control pwm signal (pwmspd) duty cycle (%) cspd voltage vs speed control pwm signal (pwmspd) duty cycle zxbm1021 document number: ds draft rev. 1 11 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) the zxbm1021 is primarily controlled by a voltage on the spd pin or a pwm signal on the pwmspd pin. a voltage of 1v represents a 100% pwm at the phase outputs and in turn represents full speed. 3v on the spd pin conversely repr esents 0% pwm. the motor can therefore be controlled simply by applying a control voltage onto the spd pin with the minimal use of extern al components. this voltage control method easily lends itself to control by other signal types. for example if a thermistor is applied to the spd pin a varying voltage can be generated at the spd pin as the resistanc e of the thermistor varies with temperature. a common form of control of fans is by a pwm signal derived from a central processor or controller. this speed control pwm sign al can be applied to pwmspd pin. motor speed is proportional to the dut y ratio of the applied pwm speed control signal on pwmspd pin. voltage on the s min pin sets the minimum speed of the motor. if the speed demand by either dc signal on spd pin or pwm signal on pwmspd pin is lower than the minimum speed setting, motor will run at minimum speed. the design of a motor system will be set around the maximum speed, the minimum speed and the current of the motor. the design o f the motor coil and the voltage on the output stage will set the maximum speed of the motor. the zxbm1021 allows easy setting and control of the minimum speed and maximum motor current, as well as for controlling the spe ed. dc speed control the spd pin will respond to an input dc voltage from 3v to 1v for 0% to 100% of the full speed. to allow internal minimum speed setting (smin) and current control (ilim) circuits to adjust the spd pin voltage, the speed contro l dc voltage signal should be driven in via a 10k ? series resistor. the series resistor allows the spd pin to vary even when driven externally by a low impedance source. a 0.1 ? f capacitor should be connected from the spd pin to supply ground. when used in dc speed control mode, pwmspd and c spd pins should be left floating. thref pwmspd c spd spd ph1lo ph2lo ph1hi setthref sense hbias zxbm1021 1 2 3 4 5 6789 10 15 14 13 12 11 20 19 18 17 16 0.1f dc speed control (3v to 1v) r 10k ? c zxbm1021 document number: ds draft rev. 1 12 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) this input also allows the fan to be driven by a thermistor, to allow the speed to be controlled according to temperature. an e xample circuit is shown below. with the values shown, and a beta value of 4000 for the ntc, t he above circuit drives the zxbm1021 with 3v (minimum speed) at 0 o c, changing to 1v (maximum speed) at 82 o c, subject to tolerances. to minimi ze additional circuitry, the 5v thref output from the zxbm1021 ic can supply the current required for the thermistor network circuit as l ong as the total current from thref does not exceed 10ma. pwm speed control an additional input allows for the use of pwm to control t he fan speed. the zxbm1021?s output speed is proportional to the duty cycle of the pwm input. when using pwmspd speed input, the spd pin should be connected to c spd with a 0.1 ? f capacitor connected to ground. pwmspd can be driven from a microcontroller with either 0-5v or 0-3.3v l ogic levels signal. the recommended frequency of the input pwm contro l signal is 25khz. thref pwmspd c spd spd ph1lo ph2lo ph1hi setthref sense hbias zxbm1021 1 2 3 4 5 6789 10 15 14 13 12 11 20 19 18 17 16 0.1f pwm speed control (ttl level, duty ratio 0% to 100%) c4 zxbm1021 document number: ds draft rev. 1 13 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) s min minimum speed setting minimum speed setting prevents the motor from running below a set speed regardless of whether the control applied is for a slow er speed (either dc or pwm input). the minimum motor s peed is chosen based on a speed below which the motor may or fail to start. the s min pin voltage sets a maximum voltage clamp for the spd pin. for a dc voltage input into spd pin, the voltage range 3v to 1v represents 0% to 100% of full speed. in order to set a minimum speed of 20%, s min should be set 20% into this range below 3v, i.e 2.6v minimum speed is set by the voltage on the s min pin, using a potential divider from the thref voltage output as shown below. the s min voltage is given by s min =thref r10 r9+r10 ? 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3 motor ?? speed ? (%) dc ? speed ? control ? voltage ? at ? spd ? pin ? (v) spd ?? and ? smin ? voltages ?? vs ? motor ? speed s min = ? 2.6v s min = ? 3v thref pwmspd spd ph1lo ph2lo ph1hi setthref sense hbias zxbm1021 1 2 3 4 5 6789 10 15 14 13 12 11 20 19 18 17 16 c spd r9 12k ? r10 13k ? zxbm1021 document number: ds draft rev. 1 14 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) thref is capable of driving 10ma, but it is not necessary to draw much current for s min . set r10+r9 in the range 5k ? -50k ? (1ma - 100a). thref may also be used to drive a thermistor circuit, so care must be taken to keep the total current drawn from thref to the c orrect level. example: required s min of 20% = 2.6v s min =thref r10 r9+r10 2.6v = 5v r10 r9+r10 solve for r9 r9 = 2.4 2.6 r10 choose r10 = 13k ? and solve for r9 which gives r9 = 12k ? . the current in r10+r9 string = 5/25000 = 200a if s min is not required, the s min pin should be pulled up externally to thref by 1k ? motor current limit the motor current limit on zxbm1021 compares the voltage on the s ense pin against the threshold voltage on the setth pin. the current limit is triggered when the voltage at the sense pin exceeds the threshol d at setth. the device lowers the output pwm drive duty ratio i f the voltage on the sense pin rises above the threshold voltage on the setth pin. the threshold value at setth pin is set us ing r7 and r8 between setthref, setth and gnd. the sense voltage is generated by the motor current flowing through the sense resistor. it is recommended to use 100m ? for the sense resistor on the sense pin, and vary the current limit by changing r7 and r8. the current limit, i lim , is given by i lim ? setthref r8 r7 r8 r sense note that setthref has a maximum output current of 200a, therefore r7+r8 must be larger than 25k ? . h+ thref pwmspd ph2hi h- spd fg ph1lo ph2lo ph1hi setthref sense setth gnd hbias zxbm1021 1 2 3 4 5 6789 10 15 14 13 12 11 20 19 18 17 16 v+op c lck s min c spd v cc r7 r8 rsense rsense motor coil zxbm1021 document number: ds draft rev. 1 15 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) example: required i lim = 2a i lim ? setthref r8 r7 r8 r sense where setthref = (thref -0.1v) = 4.9v typical 2a ? 4.9v r8 r7 r8 0.1 ? solve for r7 r7 = 4.9 0.2 r8 choose r8 = 2k ? and solve for r7 which gives r7 = 47k ? . the current in r7+r8 string = 4.9/49000 = 100a which is within maximum output current capability of the setthref pin. it is important that the current limit be set above the intended average current of the motor. in practice, due to the variable nature of the motor current through a commutation cycle, it is usually necessary fo r the current limit to be set higher than the peak current drawn at the beginning of each commutation cycle. the top trace shows the motor coil current, while the lower trace shows the sense pin voltage. as the current flow direction in the motor coil changes at each commutation cycle, the motor current in the to p trace is shown as positive and negative current. the current fl owing in the rsense is always in the same direction and therefore t he sense pin reads the magnitude of the motor coil current. current limiting may prevent the motor from reaching full speed, despite the average current being significantly lower than the current limit. the system will limit the tail-end current according to the current lim it set. current limit setting can also be used to remove the tail-end current. example of using current limit to reduce tail- end current at full speed is shown in fibelow current limit set much higher than the peak tail-end current (peak tail-end current = 180ma typ, current limit set at 0.485ma ) zxbm1021 document number: ds draft rev. 1 16 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) current limit set lower than the peak tail-end current (tail-end current = 145ma typ, current limit set at 0.166ma) c lck value the value of c lck affects three important timings for the z xbm1021: soft start, lock detect and off-time. soft start when the system is initially powered on, it will go through th e soft-start period, during which the motor is gradually ramped t o full speed. the soft start operation relies on the current control feature being implem ented and generally the current limit is set slightly above t he normal running current. in the soft start process, at power-on the voltage at c lck will rapidly increase to the low threshold, v clckthl (0.6v). then, c lck will be charged from 0.6v up to the high threshold, v clckthh (5v) at a constant current, i lckcl , which is typically 0.7a. the the time taken to charge the capacitor form v clckthl to v clckthh level depends on the value of c lck capacitor. the soft-star t time tss is given by: t ss ?? c lck ?v clckthh v clckthl i lckcl since v clckthh , v clckthl and i lckcl are fixed, this becomes simply: t ss ??c lck? ?6.29 10 for the default value of c lck, 0.47f, soft-start time is: t ss ??0.4710 ?6.29 10 0.47 6.29 2.96s this is the 3s stated in the datash eet electrical parameter section. lock detect when the motor is running, the hall sensor will follow the roto r magnetic flux density to detec t the commutation point. should the rotor lock, the signal from the hall sensor will cease. the value of c lck defines the lock detect time period before the zxbm1021 shuts down the outputs in order to prevent damage to the coil. the zxbm1021 internal system returns c lck voltage to the low threshold, v clckthl (0.6v), each time the hall s ensor provides a commutation signal. c lck then charges at the run current, i lckcr , which is typically 5.5a. if the voltage on c lck reaches the high threshold, v clckthh (5v), before the hall sensor provides the next co mmutation signal then the system will shut down by entering the lock condition. t lckdet ?? c lck ?v clckthh v clckthl i lckcr the thresholds voltage and charge current are fixed, therefore the time depends only on the value of c lck : t lckdet ??c lck? ?0.8 10 for the default value of c lck, 0.47f, t lckdet is as follows: t lckdet ??0.4710 ?0.8 10 0.47 0.8 0.376s this should not interfere with normal operation of a fan as the time period for lock detection is many times longer than the ex pected time for one revolution. as the hall sensor will detect 4 transitions in a single revolution, 0.376s between tr ansitions would equate to a r otational speed of 40rpm. for use in systems where extremely low rotation speeds ar e required, the lock detect time can be increased by making the c lck capacitor value larger. zxbm1021 document number: ds draft rev. 1 17 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) off time if the above lock detection c auses a device shutdown, c lck is used again to provide the time period, t off . this is the time for which the device will remain shut down after rotor lock is detected. the output shutdown period, t off , depends c lck being discharged from the high threshold to the low threshold at the discharge current i lckdl , typically 0.7a. t off ?? c lck ?v clckthh v clckthl i lckdl as above, the threshold voltages and discharge current are fi xed, therefore the time depends only on the value of c lck : t off ??c lck? ?6.29 10 for the default value of c lck, 0.47f, t off is as follows: t off ??0.4710 ?6.29 10 0.47 6.29 2.96s a note on probing c lck due to the very small charge and discharge currents involved with c lck , putting an oscilloscope probe onto that node can have a significant impact on the charge time. the above graph show s simulation for the impact on soft-start t ss . a typical 10x voltage probe will have 10m ? resistance, which is enough to increase soft-st art time from 3 seconds to over 5 sec onds. probing this point can be useful in u nderstanding the operation of the system but it is important to be aware of th e impact that the scope probe will have on the operation of the ci rcuit. zxbm1021 document number: ds draft rev. 1 18 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) output device driving in order to drive the output stage efficiently, it is important to minimise shoot-through currents. the zxbm1021 has a built-in delay (commutation dead-time) to allow time for re-circulating currents to be absorbed however parasitic shoot-through can still occur. this is wh en the rapid switch- on of the low-side mosfet causes a low-going pulse through the high- side mosfet to the gate, causi ng it to switch on momentaril y. slowing the switch-on of the low-side mosfet can eliminate this effect. the resistors r1 to r6 and r12 in the diagram allow for cont rol of switch-on and switch-off times for the top and bottom mosfet s separately. high-side mosfets switching speed: r3 and r5 control the discharge of the gates of the hi gh-side p-channel mosfetss, limiting the switch-on speed. r4 and r6 control the charging of the gates of t he p-channel mosfets, limiting the switch-off speed. low-side mosfets switching speed: r1 and r2 are series gate resistors for the n-channel fets, affecting both switch-on and switch-off times. r12 is the series resistor for the v+op pin of the zxbm1021. this resistor is effectively in series with r1 or r2 when that low-side n-channel device is switched on, limiting the switch-on ti me. r12 allows to vary the switch-on time relative to the switch-off time to prevent parasitic shoot-through at turn-on. when using bipolar output devices the resi stors serve similar functions in limiti ng the base currents of the transistors. thref pwmspd spd ph1lo ph2lo ph1hi setthref sense hbias zxbm1021 1 2 3 4 5 6789 10 15 14 13 12 11 20 19 18 17 16 c spd rsense motor coil r5 r3 r6 r4 r1 r2 r12 d2 d1 d1 optional, system dependent system supply (12v) zxbm1021 document number: ds draft rev. 1 19 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) external drive transistors diodes offers a range of devices that are ideally suited to in terface between the zxbm1021 pre-driver and the motor. the follow ing tables show a selection of products. for more comprehens ive listings or the latest information please refer to the diodes website: www.diodes.com mosfets part number type bvdss ( v ) id ( a ) rds(on) @ vgs = 10v (4.5v for 20v parts) ( ? ) package power switch: n-channel mosfets dmc2020usd n p 20 -20 7.4 -5.9 0.020 0.033 so8 dmc2038lvt n p 20 -20 4.5 -3.2 0.035 0.074 tsot26 dmc3028lsd n p 30 -30 7.1 -7.4 0.028 0.025 so8 dmc4040ssd n p 40 -40 7.5 -7.3 0.025 0.025 so8 dmc4028ssd n p 40 -40 7.2 -5.2 0.028 0.050 so8 zxmc4559dn8 n p 60 -60 4.7 -3.9 0.055 0.085 so8 zxmc6a09dn8 n p 60 -60 5.1 -4.8 0.045 0.055 so8 part number type bvdss ( v ) id ( a ) rds(on) @ vgs = 10v ( ? ) package power switch: n-channel mosfets zxmn10a09k n 100 7.7 0.085 to252-3l zxmn10a25k n 100 4.0 0.125 sot223 zxmn10a11g n 100 2.4 0.35 sot223 zxmn10a08dn8 2 x n 100 2.1 0.25 so8 zxmn10b08e6 n 100 1.9 0.230 sot23-6 zxmn10a07z n 100 1.4 0.7 sot89 zxmn6a09k n 60 11.2 0.04 to252-3l zxmn6a25k n 60 10.7 0.05 to252-3l dmn6068lk3 n 60 8.5 0.068 to252-3l zxmn6a09g n 60 7.5 0.04 sot223 zxmn6a25g n 60 6.7 0.05 sot223 zxmn7a11k n 60 6.1 0.120 to252-3l zxmn6a09dn8 2 x n 60 5.6 0.04 so8 dmn6068se n 60 5.6 0.068 sot223 zxmn6a08g n 60 5.3 0.08 sot223 zxmn6a25dn8 2 x n 60 4.7 0.055 so8 zxmn6a11z n 60 3.6 0.120 sot89 zxmn6a07z n 60 2.2 0.250 sot89 zxmn6a07f n 60 1.4 0.250 sot23 zxbm1021 document number: ds draft rev. 1 20 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 application note (continued) part number type bvdss ( v ) id ( a ) rds(on) @ vgs = 10v ( ? ) package power switch: p-channel mosfets zxmp10a18k p -100 -5.9 0.150 to252 zxmp10a18g p -100 -3.7 0.150 sot223 zxmp10a17e6 p -100 -1.6 0.350 sot26 zxpm6a17dn8 2 x p -60 -3.2 0.125 so8 zxmp6a18k p -60 -10.4 0.055 to252 dmp4025lsd 2 x p -40 -7.6 0.025 so8 dmp4015sps p -40 -13 0.011 powerdi5060-8 zxmp4a16g p -40 -6.4 0.060 sot223 dmp3008sfg p -30 -11.7 0.017 powerdi3333-8 bjts part number type vceo ( v ) ic ( a ) vce(sat) @ic/ib ( mv@a/ma ) package power switch: npn bjt fzt855 npn 150 4 65 @ 0.5/50 sot223 fmmt624 npn 125 1 150 @ 0.5/50 sot23 zx5t853g npn 100 6 125 @ 2/100 sot223 zxtn19100cz npn 100 5.25 65 @ 1/100 sot89 zxtn25100bfh npn 100 3 135 @ 0.5/10 sot23 zxtn25100dfh npn 100 2.5 170 @ 0.5/10 sot23 fcx493 npn 100 1 300 @ 0.5/50 sot89 fcx1053a npn 75 3 200 @ 1/10 sot89 zxtn19060cg npn 60 7 155 @ 1/10 sot223 zx5t851g npn 60 6 135 @ 2/50 sot223 dxt2010p5 npn 60 5 70 @ 1/10 powerdi5 fcx493a npn 60 1 500 @ 1/50 sot89 fcx619 npn 50 3 260 @ 2/50 sot89 fmmt619 npn 50 2 220 @ 2/50 sot23 fcx619 npn 50 3 260 @ 2/50 sot89 drive buffer and level shift fmmt493 npn 100 1 300 @ 0.5/50 sot89 fmmt493a npn 60 1 250 @ 0.5/50 sot23 zxtn2038f npn 60 1 250 @ 0.5/50 sot23 dss41604 npn 60 1 140 @ 0.5/50 sot563 zxbm1021 document number: ds draft rev. 1 21 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 thermal performance (1) package type: qfn4040-20 notes: 11. the power dissipation de-rating curve for zxbm1021 in u-qfn4040-20 package is based on 2?x2? fr4 substrate, 2oz copp er, 1.6mm thick pcb with minimum recommended pad layout on the top layer with ther mal vias to all copper bottom layer and the ?junction to ambi ent? thermal resistance (rthja) of 45c/w. 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 \ 50 \ 25 0 25 50 75 100 125 150 maximum ? power ?? (w) ambient ?? operating ? temperature ? ( o c) u \ qfn4040 \ 20 ? derating ? curve rthja ? = ? 45c/w zxbm1021 document number: ds draft rev. 1 22 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 ordering information part number package code packaging 13? tape and reel quantity part number suffix ZXBM1021JB20TC jb20 u-qfn4040-20 3000/tape & reel tc marking information (1) package type: u-qfn4040-20 part number package identification code ZXBM1021JB20TC qfn4040-20 zxbm 1021 zxbm1021 document number: ds draft rev. 1 23 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 package outline dimensions (all dimensions in mm.) please see ap02002 at http://www.diodes.com /datasheets/ap02002.pdf for latest version. (1) package type: u-qfn4040-20 suggested pad layout please see ap02001 at http://www.diodes.com/dat asheets/ap02001.pdf for the latest version. (1) package type: u-qfn4040-20 u-qfn4040-20 dim min max typ a 0.55 0.65 0.60 a1 0 0.05 0.02 a3 - - 0.15 b 0.20 0.30 0.25 d 3.95 4.05 4.00 d2 2.40 2.60 2.50 e 3.95 4.05 4.00 e2 2.40 2.60 2.50 e 0.50 bsc l 0.35 0.45 0.40 z - - 0.875 all dimensions in mm dimensions v alue (in mm) c 0.500 x 0.350 x1 0.600 x2 2.500 x3 4.300 y 0.600 y1 0.350 y2 2.500 y3 4.300 d d2 e b l e2 a a1 a3 (pin #1 id) seating plane z (8x) e 1 y3 x3 y1(10x) x1(10x) y2 x2 x(1 0 x) c y(10x) zxbm1021 document number: ds draft rev. 1 24 of 24 www.diodes.com june 2013 ? diodes incorporated zxbm1021 important notice diodes incorporated makes no warranty of any kind, express or implied, with regards to this document, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose (and their equivalents under the laws of any jurisdiction). diodes incorporated and its subsidiaries re serve the right to make modifications, enhanc ements, improvements, corrections or ot her changes without further notice to this document and any product described herein. diodes incorporated does not assume any liability ari sing out of the application or use of this document or any product described her ein; neither does diodes inco rporated convey any license under its patent or trademark rights, nor the rights of others. any customer or us er of this document or products described herein in such applica tions shall assume all risks of such use and will agree to hold diodes incorporated and all the companies whose products are represented on diodes incorporated website, harmless against all damages. diodes incorporated does not warrant or accept any liability what soever in respect of any pr oducts purchased through unauthoriz ed sales channel. should customers purchase or use diodes in corporated products for any unintended or unaut horized application, customers shall i ndemnify and hold diodes incorporated and its representat ives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death a ssociated with such unintended or unauthorized application. products described herein may be covered by one or more united states, international or foreign patents pending. product names and markings noted herein may also be covered by one or more united states, international or foreign trademarks. this document is written in english but may be translated into multiple languages for reference. only the english version of t his document is the final and determinative format released by diodes incorporated. life support diodes incorporated products are specifically not authorized for use as critical comp onents in life support devices or systems without the express written approval of the chief executive offi cer of diodes incorporated. as used herein: a. life support devices or syst ems are devices or systems which: 1. are intended to implant into the body, or 2. support or sustain life and whose failure to perform when proper ly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in significant injury to the user. b. a critical component is any component in a life support devic e or system whose failure to perform can be reasonably expect ed to cause the failure of the life support device or to affect its safety or effectiveness. customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support dev ices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning the ir products and any use of diodes incorporated products in such safety-critica l, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by diodes incorporated. further, customers must fully indemnify diodes incorporate d and its representatives against any damages arising out of the use of diodes incorporated products in such safety-critical, life suppor t devices or systems. copyright ? 2013, diodes incorporated www.diodes.com |
Price & Availability of ZXBM1021JB20TC |
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
[Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |