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201002244-1/12 this datasheet contains new product information. advanced power electronics corp. reserves the rights to modify the product specification without notice. no liability is assumed as a result of the use of this product. no rights under any patent accompany the sale of the product. APE1601/a white led driver (120ma charge pump with current source) ? general description the APE1601 is a high efficiency charge pump white led driver. it supports up to 4 white leds with regulated constant curr ent for uniform intensity. the APE1601 maintains the highest efficiency by utilizi ng a x1/x1.5/x2 fractional charge pump and low dropout current regulators. user can easily configure each led current up 30ma by an external resistor. two digital inputs can be programmable to cont rol white led on/off. led dimming can be achieved by applying a pwm signal to the digital control signals. the operating voltage range is 2.5v to 5.5v. internal soft-start circuitry effectivel y reduces the in-rush current both while start-up and mode change. APE1601 also provides comprehensive protections such short circuit protection and over-temperature protection. the load is disconnected from vin while shutdown and the shutdown current is less than 1ua. APE1601 is available in a qfn 3x3mm-16l package. ? features - very high efficiency over 90% of battery life - support up to 4 wleds - support up to 120ma output current - soft start / short circuit protection function - three charge pump mode: x1, x1.5, x2 - 250k/1mhz fixed frequency oscillator - rohs compliant and 100% lead (pb)-free ? block diagram vout 250k/1mhz oscillation agnd iset is current brightness and setting control circuit x1/x1.5/x2 charge pump mode decision output selection logic current set detect bandgap voltage led4 led3 led2 led1 ctrl0 ctrl1 c1p c1n c2p c2n pgnd en vin adva nced power electronics corp.
2/12 APE1601/a ? pin assignmet ( qfn 3x3mm -16l) table 1 control inputs output status ctrl1 ctrl0 led4 led3 led2 led1 0 0 off off on on 0 1 off on on on 1 0 on on on on 1 1 off off off off 2 6 12 9 10 5 13 16 1 3 4 78 11 14 15 (top view) en ctrl0 ctrl1 agnd pgnd c2p c2n iset vout vin c1p led1 led2 led3 led4 c1n thermal pad (gnd) pin name description 1 en chip enable (active high). there should be a pull low 100k ? 2 ctrl0 output control bit 0. (see table 1) 3 ctrl1 output control bit 1. (see table 1) 4 agnd analog ground 5 iset led current is set by the value of the resistor r set connected from the iset pin to ground. do not short the iset pin. v iset is typically 1.2v. all external capacitance at this pin, in cluding board parasitic capacitance, must be less than or equal to 30pf. 6 vout output voltage source for connection to the led anodes. 7 vin input voltage 8 c1p positive terminal of bucket capacitor 1 9 c1n negative terminal of bucket capacitor 1 10 c2n negative terminal of bucket capacitor 2 11 c2p positive terminal of bucket capacitor 2 12 pgnd power ground. 13 to 16 led4~1 current sink for led. (if not in use, pin should be connected to v out ) (1) pad gnd exposed pad should be soldered to pcb board and connected to gnd. (1) the ctrl word must match the output in use. ? order/marking information order information top marking package type vn3 : qfn 3x3-16l APE1601x x frequency blank : 1.0mhz a : 250khz x x x x x 1601 x part number id code : internal ww : 01 ~ 52 year : 06 = 2006 blank : APE1601 a : a pe1601a adva nced power electronics corp. white led driver (120ma charge pump with current source)
3/12 ? absolute maximum ratings (at ta=25 pe1601 0.8 1.0 1.2 mhz oscillator frequency f osc APE1601a 200 250 300 khz input current limit i lim short circuit applied from v out to gnd 450 -- 850 ma output over voltage protect v ovp open circuit at any led that is programmed to be in the on state -- 5.5 6 v v ih input high (en,ctrl0,ctrl1) 2.0 -- -- en pin logic input threshold voltage v il input low (en,ctrl0,ctrl1) -- -- 0.8 v APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
4/12 i ih v en =v in (on) -- -- 1 ua en pin input current i il v en =gnd (off) -- -- 1 ua thermal shutdown temp tsd 150 : thermal shutdown hysteresis 15 : note 1. x100% accuracy i i i i led(set) led(set) ed) led(measur led ? = note 2. cu rrent matching refers to the difference in current from on led to the next. x100% matching current i i i i i led(min) led(max) led(min) led(max) led + ? =
5/12 c. for 2 wleds back light d2 vin=2.5~5.5v d1 cin 1uf cout 1uf r1 rset c2 0.1uf c1 0.1uf u1 APE1601 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 en ctrl0 ctrl1 gnd iset vout vin c1p cin c2n c2p pgnd led4 led3 led2 led1 vin=2.5~5.5v c2 0.1uf d2 u1 APE1601 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 en ctrl0 ctrl1 gnd iset vout vin c1p cin c2n c2p pgnd led4 led3 led2 led1 r1 rset c1 0.1uf cin 1uf cout 1uf d1 d. for 3 wleds camera flash module c2 0.1uf r2 radj cout 1uf r1 rset c1 0.1uf u2 1 2 3 base band gpio2 gpio1 r2 100k u1 APE1601 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 en ctrl0 ctrl1 gnd iset vout vin c1p cin c2n c2p pgnd led4 led3 led2 led1 cin 1uf vdd vin=2.5~5.5v flash led device c1 (uf) c2 (uf) APE1601(1mhz) 0.1 0.1 APE1601a(250khz) 0.47 0.47 gpio2: high : vdd (movie mode) low : 0v (strobe mode) APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
6/12 ? function descriptions the APE1601/a is a high efficiency charge pump white led driver. it provides 4 channels low drop-out voltage current sour ce to regulated 4 white leds current. for high efficiency, the APE1601/a implements x1/x1.5/x2 mode charge pump. an external r set is used to set the current of white led. APE1601/a has an input current regulation to reduce the input ripple. soft start the APE1601/a includes a soft start circuit to limit the inrush current at power on and mode switching. soft start circuit holds t he input current level long enough for output capacitor c out reaching a desired voltage level. mode decision the APE1601/a uses a smart mode decision method to select the working mode for maximum efficiency. mode decision circuit senses the output and led voltage for up/down selection. dimming control ctrl0 and ctrl1 are used to control the on/off of white led. when an external pwm signal is connected to the cont rol pin, brightness of white le d is adjusted by the duty cycle. led current setting the current of white led connec ted to APE1601/a can be set by r set . every current flows through the white led is 400 time s greater than the current of r set . the white led can be estimated by following equation: ? 1 ? u set iset led r v i 400 where v iset = 1.2v, and r set is the resistance connected from i set to gnd. thermal shutdown the APE1601/a provides a high current capability to drive 4 white leds. a thermal shutdown circuit is needed to protect the ch ip from thermal damage. when the chip reaches the shutdown temperature 150c, the t hermal shutdown circuit turns off the chip to prevent the thermal accumulation in the chip. over voltage protection the APE1601/a regulates the output voltage by controlling the input current. when the output voltage reaches the designated level, t he APE1601/a reduces the input current. and then, the output voltage regulation also serves an over-voltage protection. APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
7/12 short circuit protection a current limiting circuit is also included in the APE1601/a for short circuit protection. whenever output source a dangerously high curren t, the current limiting circuit takes over the output regulation circuit and reduces t he output current at an acceptable level. ? application information selecting capacitors to get the better performance of APE1601/a, the selecting of peripherally appropriate capacitor and value is very important. thes e capacitors determine some parameters such as input and output ripple, power efficiency, maximum supply current by charge pump, and start-up time. to reduce the input and output ripple effectively, the low esr ceramic capacitors are recommended. generally, to reduc e the output ripple, increasing the output capacitance c out is necessary. however, this will increase the start-up time of output voltage. for led driver applicat ions, the input voltage ripple is more important than output ripple. input ripple is controlled by input capacitor c in , increasing the value of input capacitance can further reduce the ripple. pr actically, the input voltage ripple depends on the power supply?s impedance. if a single input capacitor c in cannot satisfy the requirement of application, it is necessary to add a low-pass filter as shows in figure 1. 2.2uf APE1601/a vin vin gnd 2.2uf 1 frgure1. c-r-c filter used to reduce input ripple the flying capacitor c1 and c2 determine the supply current capability of the charge pump and to influence the overall efficiency of system. the lower value will improve efficiency, but it will limit the le d? s current at low input voltage. APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
8/12 setting the led current the APE1601/a can be set a fixed leds current by a resister rset connected from iset to gnd. rset establishes the reference curr ent and mirrors the current into led1, led2, led3, and led4. the current into led is about 400 times of the current flows through the rset, the approximate setting formula is given as follows: ? 1 ? u set led r v . ) a ( i 2 1 400 (1) figure 2 shows the typical value of rset versus average led current and table 2 shows the values of rset for a fixed led current. 0 10 20 30 40 50 60 70 80 90 100 0 5 10 15 20 25 30 led average current (ma) r set (k ?
9/12 led current setting with nmos led current setting control can also be achieved by using the external nmos to change equivalent resister of iset pin. figure 3 shows this applicati on circuit of method. for this example, a 3 bit signals can set 8 kinds of differ ent equivalent resister of iset pin, i.e. produce 8 kinds of led current level. t able 3 shows the relation between equivalent resister of iset pin and control signal. APE1601 /a i set gnd r1 r4 s1 r2 s2 r3 s3 figure 3. the application circui t of setting led current which uses a nmos to set r set . table 3. the relation between control signal and equivalent resister of i set pin s1 s2 s3 equivalent resister of i set pin(r set ) 0 0 0 r set =r4 0 0 1 r set =r3//r4 0 1 0 r set =r2//r4 0 1 1 r set =r2//r3//r4 1 0 0 r set =r1//r4 1 0 1 r set =r1//r3//r4 1 1 0 r set =r1//r2//r4 1 1 1 r set =r1//r2//r3//r4 led dimming control methods the APE1601/a can use two methods to achieve the led dimming control. these methods are detailed described as following: APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
10/12 (1). dimming using pwm si gnal into ctrl0 and ctrl1 led current can be controlled by applying a pwm signal to ctrl0 or ctrl1. table 4 shows the relation between ctrlx and 4 led's current states. for an example, as the ctrl1 is pulled logical high and ctrl0 rece ives a pwm signal, then, four leds will be dimmed synchronously. here, the pwm signal setting the led's current on/off can achieve the average led's current which in des ign. the application circuit is shown in figure 4. figure 5, and figure 6 show 3weds and 2wleds pwm dimming application circuit, respectively. during the time of pwm signal logical low, the current is a fixed value and setting by rset resistor. so the average leds current can be approximated as equation (3). ? ? ? 1 ? pwm ) on ( led x off ) avg ( led t i t i (3) where: t pwm is the period of pwm dimming signal t off is the time of pwm signal at low. i led(on) is led on state current. table 4. the relation between ctrlx and 4 led's current states control inputs output status ctrl1 ctrl0 led4 led3 led2 led1 0 0 off off on on 0 1 off on on on 1 0 on on on on 1 1 off off off off APE1601/a ctrl1 gnd ctrl0 en vin gpio pwm led off led on figure 4. the pwm dimming app lication circuit for 4wleds APE1601/a ctrl1 gnd ctrl0 en vin gpio pwm led off led on figure 5. the pwm dimming app lication circuit for 3wleds APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
11/12 APE1601 ctrl1 gnd ctrl0 en gpio pwm led off led on figure 6. the pwm dimming app lication circuit for 2wleds besides, APE1601/a has 100us delay time between mode transfer. this delay time makes different dimming frequency corresponds to diffe rent maximum duty of ctrlx pin. when the duty cycle of dimming frequency excess maxi mum duty, the APE1601/as can't transfer the mode normally. equation (4) shows the re lation between maximum duty of ctrlx pin and pwm dimming frequency. table 5 is shown the common dimming frequency and its corresponding maximum duty. for better perfo rmance consideration, the maximum pwm dimming frequency is recommended below 1 khz. d (max) = (1 - 100x10 -6 x f d ) (4) where: d max is maximum duty of ctrlx f d is pwm dimming frequency table 5. the common dimming frequency and its corresponding maximum duty. dimming frequency (hz) ctrlx maximum duty iled minimum duty 1k 0.90 0.10 900 0.91 0.09 800 0.92 0.08 700 0.93 0.07 600 0.94 0.06 500 0.95 0.05 400 0.96 0.04 300 0.97 0.03 200 0.98 0.02 APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
12/12 pcb board layout the APE1601/a is a high-frequency switched-capacitor converter. for best performance, place all of the components as close to ic as possible. besides a solid ground plane is recommended on the bottom layer of the pc b. the ground should be connected cin and cout together and as close to the ic as possi ble. figure 7 shows the typical layout of APE1601/a? s evb board. top layer bottom layer figure 7. typical layout of APE1601/a?s evb board APE1601/a adva nced power electronics corp. white led driver (120ma charge pump with current source)
package outline : qfn 3x3-16l min nom max a 0.750 0.850 0.950 a1 a2 b 0.180 0.230 0.300 d 2.950 3.000 3.050 d2 1.450 1.600 1.750 e 2.950 3.000 3.050 e2 1.450 1.600 1.750 e l 0.350 0.400 0.450 y qfn 3x3-16l advanced power electronics corp. millimeters 0.500 0.080 yywws) yy 1601x yywws part number blank : 1mhz a : 250khz

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