View FAN5333ASX_8953109.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

?005 fairchild semiconductor corporation 1 www.fairchildsemi.com a ugust 2005 f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch features 1.5mhz switching frequency low noise adjustable output voltage up to 1.5a peak switch current 1.5w output power capability low shutdown current: <1? cycle-by-cycle current limit low feedback voltage over-voltage protection fixed-frequency pwm operation internal compensation f an5333a has 110mv feedback voltage f an5333b has 315mv feedback voltage thermal shutdown 5-lead sot23 package applications cell phones pdas handheld equipment display bias led bias flash led description the fan5333a/fan5333b is a general purpose led driver that f eatures ?ed frequency mode operation and an integrated fet s witch. the devices high output power makes it suitable to drive ?sh leds in serial connections. this device is designed to operate at high switching frequencies in order to minimize s witching noise measured at the battery terminal of hand-held communications equipment. quiescent current in both normal and shutdown mode is designed to be minimal in order to e xtend battery life. normal or shutdown mode can be selected by a logic level shutdown circuitry. the low on-resistance of the internal n-channel switch ensures high ef?iency and low power dissipation. a cycle-by-cycle cur- rent limit circuit keeps the peak current of the switch below a typical value of 1.5a. the fan5333a/fan5333b is available in a 5-lead sot23 package. t ypical application figure 1. typical application diagram shdn v in v out r gnd v in fb sw c in 6.8 h to 10 h 1 3 2 4 5 4.7 f to 10 f c out l bat54 i led 0.1 f to 2.2 f on off i led2 i led1 r1 r2 fa n5333
2 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch pin assignment figure 2. pin assignment pin description pin no. pin name pin description 1sw switching node . 2 gnd analog and power ground . 3fb feedback pin. feedback node that connects to an external current set resistor. 4 shdn shutdown control pin. logic high enables, logic low disables the device. 5v in input voltage pin . top view 5-lead sot-23 sw gnd fb v in shdn
3 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch absolute maximum ratings ( note1) recommended operating conditions notes: 1. stresses above those listed under ?bsolute maximum ratings?may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational se ction of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. absolute maximum ratings apply individually only, not in combination. 2. using eia/jesd22a114b (human body model) and eia/jesd22c101-a (charge device model). 3. this load capacitance value is required for the loop stability. tolerance, temperature variation, and voltage dependency of t he capacitance must be considered. typically a 1? ceramic capacitor is required to achieve specified value at v out = 30v. p arameter min max unit v in to gnd 6.0 v fb, shdn to gnd -0.3 v in + 0.3 v sw to gnd -0.3 35 v lead soldering temperature (10 seconds) 300 ? j unction temperature 150 ? storage temperature -55 150 ? thermal resistance ( ja ) 210 ?/w electrostatic discharge protection (esd) level (note 2) hbm 2 kv cdm 1 p arameter min typ max unit input voltage 1.8 5.5 v output voltage v in 30 v operating ambient temperature -40 25 85 ? output capacitance rated at the required output (note 3) for maximum load current 0.47 ?
4 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch electrical characteristics t est circuit figure 3. test circuit unless otherwise noted, v in = 3.6v, v out = 20v, i led = 20ma, t a = -40? to 85?, typical values are at t a = 25?, test circuit, figure 3. p arameter conditions min. typ. max. units f eedback voltage fan5333a 99 110 121 mv f an5333b 299 315 331 mv switch current limit v in = 3.2v 1.1 1.5 a load current capability v out 20v, v in = 3.2v 65 ma switch on-resistance v in = 5v 0.6 ? v in = 3.6v 0.7 ? quiescent current v shdn = 3.6v, no switching 0.6 ma off mode current v shdn = 0v 0.1 3 a shutdown threshold device on 1.5 v device off 0.5 v shutdown pin bias current v shdn = 0v or v shdn = 5.5v 1 300 na f eedback pin bias current 1 300 na f eedback voltage line regulation 2.7v < v in < 5.5v, v out 20v 0.3 % switching frequency 1.2 1.5 1.8 mhz maximum duty cycle 87 93 % switch leakage current no switching, v in = 5.5v 1 a ovp 15 % thermal shutdown temperature 150 ? shdn v in v out r gnd v in fb sw c in 10 h 1 3 2 4 5 10 f c out l bat54 i led 1 f on off electronic load fa n5333
5 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch t ypical performance characteristics t a = 25?, c in = 4.7?, c out = 0.47?, l = 10?, unless otherwise noted. 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 50 60 70 80 90 100 50 60 70 80 90 100 efficiency vs. input voltage i nput voltage( v ) efficiency (%) i led = 10ma v out = 9v i led = 20ma i led = 30ma i led = 40ma 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 ef fi ciency vs. input voltage i nput voltage( v ) efficiency (%) v out = 15v i led = 20ma i led = 30ma i led = 40ma i led = 10ma 2345 0 50 100 150 200 250 300 maximum load current vs. input voltage maximum load current (ma) input voltage ( v ) t a = -40c t a = 25c t a = 85c 2.0 2.5 3.0 3.5 4.0 0 50 100 150 200 m aximum load current vs.input voltage in put volt age ( v ) maximum load cu rrent (ma) v out = 14.2v v out = 9.3v v out = 12.3v -40 -20 0 2 0406080 9.6 9.8 10.0 10.2 10.4 10.6 10.8 led cu rrent vs temperature le d current ( ma ) temperat ure ( ? ) v in = 2.2v v in = 3.6v v in = 5.5v v out = 15v i led <5% c in = 10f v out = 15v i led <5% c in = 10f c out = 1f ? i led <5% c in = 10f c out = 1f -40 -20 0 2 0406080 1.2 1.4 1.6 1.8 2.0 sw frequency vs temperature tempera ture ( ? ) sw frequenc y (m hz) v in = 2.2v v out = 15v v in = 3.6v v in = 5.5v c out = 1f
6 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch t ypical performance characteristics (contd.) t a = 25?, c in = 4.7?, c out = 0.47?, l = 10?, unless otherwise noted. 2 345 0 5 10 15 20 25 v out = 15v load current vs.input voltage input voltage ( v ) load current (ma) start-up response time (100 s/div) (5v/div) volt age output volt age battery current (5v/div) (0.5a/div) en l = 10h c in = 10f c out = 1f v in = 2.7v
7 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch block diagram figure 4. block diagram circuit description the fan5333a/fan5333b is a pulse-width m odulated (pwm) current-mode boost converter. the fan5333a/fan5333b improves the performance of battery powered equipment by signif- icantly minimizing the spectral distribution of noise at the input caused by the switching action of the regulator. in order to facilitate effective noise ?tering, the switching frequency was chosen to be high, 1.5mhz. the device architecture is that of a current mode controller with an internal sense resistor connected in series with the n-channel switch. the voltage at the feedback pin tracks the output voltage at the cathode of the external schottky diode (shown in the test circuit). the error ampli?r ampli?s the difference between the feedback voltage and the internal band- gap reference. the ampli?d error voltage serves as a refer- ence voltage to the pwm comparator. the inverting input of the pwm comparator consists of the sum of two components: the ampli?d control signal received from the 30m ? current sense resistor and the ramp generator voltage derived from the oscilla- tor. the oscillator sets the latch, and the latch turns on the fet s witch. under normal operating conditions, the pwm compara- tor resets the latch and turns off the fet, thus terminating the pulse. since the comparator input contains information about the output voltage and the control loop is arranged to form a negative feedback loop, the value of the peak inductor current will be adjusted to maintain regulation. every time the latch is reset, the fet is turned off and the cur- rent ?w through the switch is terminated. the latch can be reset by other events as well. over-current condition is moni- tored by the current limit comparator which resets the latch and turns off the switch instantaneously within each clock cycle. over-voltage protection the voltage on the feedback pin is sensed by an ovp compar- ator. when the feedback voltage is 15% higher than the nominal v oltage, the ovp comparator stops switching of the power tran- sistor, thus preventing the output voltage from going higher. open-circuit protection as in any current regulator, if the feedback loop is open, the out- put voltage increases until it is limited by some additional exter- nal circuitry. in the particular case of the fan5333, the output v oltage is limited by the switching transistor breakdown at around 45v, typically (assuming that c out and the schottky diode rating voltage are higher). since at such high output volt- age the output current is inherently limited by the discontinuous conduction mode, in most cases, the switching transistor enters non-destructive breakdown and the ic survives. however, to ensure 100% protection for led disconnection, we recommend limiting v out with an external zener diode or stop- ping the boost switching with an external voltage supervisory circuit. applications information setting the output current the internal reference (v ref ) is 110mv (typical) for fan5333a and 315mv (typical) for fan5333b. the output current is set by a resistor divider r connected between fb pin and ground. the output current is given by reference oscillator n fb fb amp driver comp - - + + s ramp generator r r r q s current limit comparator 30m ? 1.15 x v ref shutdown circuitry thermal shutdown shdn gnd sw v in amp error 45 1 2 3 + over vo ltage comp + - - + - i led v fb r ---------- =
8 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch inductor selection the inductor parameters directly related to device performances are saturation current and dc resistance. the fan5333a/ f an5333b operates with a typical inductor value of 10?. the lower the dc resistance, the higher the ef?iency. usually a trade-off between inductor size, cost and overall ef?iency is needed to make the optimum choice. the inductor saturation current should be rated around 1a, in an application having the led current near the maximum cur- rent as indicated in ?ypical performance characteristics? the peak inductor current is limited to 1.5a by the current sense loop. this limit is reached only during the start-up and with heavy load condition; when this event occurs the converter can shift over in discontinuous conduction mode due to the auto- matic turn-off of the switching transistor, resulting in higher rip- ple and reduced ef?iency. some recommended inductors are suggested in the table below: ta b le 1: recommended inductors capacitors selection f or best performance, low esr input and output capacitors are required. ceramic capacitors of c in = 10? and c out = 1? placed as close to the ic pins, are required for the maximum load(65ma). for the lighter load ( 20ma ) the capacitances may be reduced to c in = 4.7? and c out = 0.47? or even to 0.1?, if higher ripple is acceptable. the output capacitor voltage rating should be according to the v out setting. some capacitors are suggested in the table below. ta b le 2: recommended capacitors diode selection the external diode used for recti?ation is usually a schottky diode. its average forward current and reverse voltage maxi- m um ratings should exceed the load current and the voltage at the output of the converter respectively. a barrier schottky diode such as bat54 is preferred, due to its lower reverse current over the temperature range. care should be taken to avoid any short circuit of v out to gnd, ev en with the ic disabled, since the diode can be instantly dam- aged by the excessive current. brightness control 1. dimming using pwm logic signal a pwm signal applied to shdn ta b le 5 on page 8 can control the leds brightness in direct dependence with the duty cycle. the maximum frequency should not exceed 1khz to ensure a linear dependence of the leds average current. the amplitude of the pwm signal should be suitable to turn the fan5333 on and off. alternatively, a pwm logic signal can be used to switch a fet on/off to change the resistance that sets the leds current ta b le 6 on page 8. adjusting the duty cycle from 0% to 100% results in varying the leds current between i min and i max . where figure 5. dimming using a pwm signal figure 6. dimming using a pwm logic signal 2. dimming using dc voltage an external adjustable dc voltage table 7 on page 8 between 0v to 2v can control the leds current from 15ma to 0ma, respectively. figure 7. dimming using dc voltage inductor v alue vendor part number com- ment 10? tdk slf6025&-100m1r0 10? murata lqh66sn100m01c highest ef?iency 10? cooper sd414-100 small size capacitor v alue vendor part number 0.47? panasonic ecj-3yb1e474k 1? murata grm21br61e105k 10? murata grm21br61a106k i min v fb r min ------------- = a nd i max v fb r min r set -------------------------------- = shdn fa n5333 fb fa n5333 r min r set fb v dc 90k ? 5 ? 1.6k ? f an5333a fb v dc 90k ? 15 ? 4.7k ? fa n5333b
9 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch 3. dimming using filtered pwm signal this method allows the use of a greater than 1khz pwm fre- quency signal with minimum impact on the battery ripple. the ?tered pwm signal table 8 on page 9 acts as an adjustable dc v oltage as long as its frequency is signi?antly higher than the corner frequency of the rc low pass ?ter. figure 8. dimming using filtered pwm signal thermal shutdown when the die temperature exceeds 150?, a reset occurs and will remain in effect until the die cools to 130?, at that time the circuit will be allowed to restart. pcb layout recommendations the inherently high peak currents and switching frequency of power supplies require careful pcb layout design. therefore, use wide traces for high current paths and place the input capacitor, the inductor, and the output capacitor as close as possible to the integrated circuit terminals. the fb pin connec- tion should be routed away from the inductor proximity to pre- v ent rf coupling. a pcb with at least one ground plane connected to pin 2 of the ic is recommended. this ground plane acts as an electromagnetic shield to reduce emi and parasitic coupling between components. fb 20k ? 15k ? 5 ? 1.6k ? fa n5333a 0.1 f fb 20k ? 15k ? 15 ? 4.7k ? fa n5333b 0.1 f
10 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch mechanical dimensions 5-lead sot-23 ordering information symbol inches millimeters notes min max min max a .035 .057 .90 1.45 a1 .000 .006 .00 .15 b .008 .020 .20 .50 c .003 .010 .08 .25 d .106 .122 2.70 3.10 e .059 .071 1.50 1.80 e .037 bsc .95 bsc e1 .075 bsc 1.90 bsc h .087 .126 2.20 3.20 l .004 .024 .10 .60 0 10 0 10 product number package type order code f an5333a 5-lead sot23 FAN5333ASX f an5333b 5-lead sot23 fan5333bsx d e1 e b e h a a1 l c
11 www.fairchildsemi.com f an5333a/fan5333b rev. 1.0.1 f an5333a/fan5333b high ef?iency, high current serial led driver with 30v integrated switch disclaimer fairchild semiconductor reserves the right to make changes without further notice to any products herein to improve reliability, function or design. fairchild does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights, nor the rights of others. trademarks the following are registered and unregistered trademarks fairchild semiconductor owns or is authorized to use and is not intended to be an exhaustive list of all such trademarks. life support policy f airchild?s products are not authorized for use as critical components in life support devices or systems without the express written approval of fairchild semiconductor corporation. as used herein: 1. life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, or (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in significant injury to the user. 2. a critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. product status definitions definition of terms datasheet identification product status definition advance information preliminary no identification needed obsolete this datasheet contains the design specifications for product development. specifications may change in any manner without notice. this datasheet contains preliminary data, and supplementary data will be published at a later date. fairchild semiconductor reserves the right to make changes at any time without notice in order to improve design. this datasheet contains final specifications. fairchild semiconductor reserves the right to make changes at any time without notice in order to improve design. this datasheet contains specifications on a product that has been discontinued by fairchild semiconductor. the datasheet is printed for reference information only. formative or in design first production full production not in production isoplanar? littlefet? microcoupler? microfet? micropak? microwire? msx? msxpro? ocx? ocxpro? optologic ? optoplanar? p acman? pop? power247? poweredge? f ast ? f astr? fps? frfet? globaloptoisolator? gto? hisec? i 2 c? i-lo ? implieddisconnect? intellimax? rev. i16 acex? activearray? bottomless? build it now? coolfet? crossvolt ? dome? ecospark? e 2 cmos? ensigna? f act? f act quiet series? powersaver? powertrench ? qfet ? qs? qt optoelectronics? quiet series? rapidconfigure? rapidconnect? serdes? silent switcher ? smart start? spm? s tealth? superfet? supersot?-3 supersot?-6 supersot?-8 syncfet? tinylogic ? tinyopto? trutranslation? uhc? ultrafet ? unifet? vcx? wire? across the board. around the world.? the power franchise ? programmable active droop?

▲Up To Search▲

Price & Availability of FAN5333ASX

	To Download FAN5333ASX Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .