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RT9363A 1 ds9363a-03 april 2011 www.richtek.com ordering information (top view) wdfn-10l 3x3 note : richtek products are : ` rohs compliant and compatible with the current require- ments of ipc/jedec j-std-020. ` suitable for use in snpb or pb-free soldering processes. pin configurations applications z mobile phone, dsc, mp3 z white led backlighting z lcd display supply marking information for marking information, contact our sales representative directly or through a richtek distributor located in your area. 3 channels 90ma x1/x2 charge pump white led driver general description the RT9363A is a compact, high efficient and highly integrated charge pump white led driver. it maintains the highest efficiency by utilizing a x1/x2 fractional charge pump and low dropout current regulators. the RT9363A supports up to 3 white leds and regulates a constant current for uniform intensity. the part implements a 4-bit dac for brightness control. users can select external r set or internal r set by iset pin. the dimming of white leds' current can be achieved by applying a pulse signal to the en pin. there are totally 16 steps of current could be set by users. the part can support 15ma to 30ma for the 100% current setting. users also can use the internal r set for 100% current setting of 20ma just by connecting the iset pin to v in . the operating voltage range is from 2.8v to 5.5v. internal soft start circuitry effectively reduces the in- rush current while both start-up and mode transition. the load is disconnected from v in while shutdown and the shutdown current is less than 1ua. RT9363A is available in a wdfn -10l 3x3 package. features z z z z z over 80% average efficiency over battery life z z z z z support up to 3 white leds z z z z z 80mv typical current source dropout z z z z z support up to 90ma output current z z z z z 1% typical led current accuracy z z z z z 0.7% typical led current matching z z z z z soft start function z z z z z automatic charge pump mode selection z z z z z 1mhz random frequency oscillator z z z z z over voltage protection z z z z z 16-step brightness control z z z z z low input noise and emi z z z z z low 1ua shutdown current z z z z z flexible current setting z z z z z rohs compliant and 100% lead (pb)-free led3 led2 cp cn en iset vout gnd vin led1 9 8 7 9 1 2 3 4 5 10 gnd 11 package type qw : wdfn-10l 3x3 (w-type) lead plating system p : pb free g : green (halogen free and pb free) RT9363A
RT9363A 2 ds9363a-03 april 2011 www.richtek.com typical application circuit vin vout led3 RT9363A gnd + c in 2.2uf led1 led2 li-ion battery c out 2.2uf 1 9 6 7 3 2 iset en gpio c fly 1uf 8 10 cn cp 4 5 vin vout led3 RT9363A gnd + c in 2.2uf led1 led2 li-ion battery c out 2.2uf 1 9 6 7 3 2 iset en gpio c fly 1uf 8 10 cn cp 4 5 vin vout led3 RT9363A gnd + c in 2.2uf led1 led2 li-ion battery c out 2.2uf 1 9 6 7 3 2 iset en gpio c fly 1uf 8 10 cn cp 4 5 r set vin vout led3 RT9363A gnd + c in 2.2uf led1 led2 li-ion battery c out 2.2uf 1 9 6 7 3 2 iset en gpio c fly 1uf 8 10 cn cp 4 5 r set figure 1. internal r set(max) = 20ma, for 3-wleds application circuit figure 2. internal r set(max) = 20ma, for 2-wleds application circuit figure 3. external r set(max) = 15 to 30ma, for 3-wleds application circuit figure 4. external r set(max) = 15 to 30ma, for 2-wleds application circuit
RT9363A 3 ds9363a-03 april 2011 www.richtek.com functional pin description pin no. pin name pin function 1 led3 current sink for led3. (if not in use, this pin must be connected to v in ). 2 led2 current sink for led2. (if not in use, this pin must be connected to v in ). 3 led1 current sink for led1. (if not in use, this pin must be connected to v in ). 4 cn negative terminal of bucket capacitor. 5 cp positive terminal of bucket capacitor. 6, 11 (exposed pad) gnd ground. the exposed pad must be soldered to a large pcb and connected to gnd for maximum power dissipation. 7 vin input voltage. 8 vout output voltage source for led1~3. 9 iset led current adjust input. 10 en chip enable (active high). timing diagram figure 5. pulse dimming waveform 0.5us < t lo < 500us 30us < t ready 2ms < t shdn 15/16 14/16 13/16 12/16 1/16 2/16 100% 100% 15/16 01234 5 14 15 0 1 en iledx shutdown shutdown 0.5us < t hi
RT9363A 4 ds9363a-03 april 2011 www.richtek.com function block diagram en led1 led2 led3 1mhz osc 16 steps pulse dimming controller soft start circuit current source shutdown delay vin vout gate driver uvlo min vds + - cp cn mode decision current bias vr1 ovp r set selection r set iset gnd
RT9363A 5 ds9363a-03 april 2011 www.richtek.com electrical characteristics absolute maximum ratings (note 1) z supply input voltage ------------------------------------------------------------------------------------------------------ ? 0.3v to 6v z output voltage s ----------------------------------------------------------------------------------------------------------- ? 0.3v to 6v z power dissipation, p d @ t a = 25 c wdfn 10l 3x3 ------------------------------------------------------------------------------------------------------------- 1.538w z package thermal resistance (note 2) wdfn 10l 3x3, ja ------------------------------------------------------------------------------------------------------- 60 c/w wdfn 10l 3x3, jc ------------------------------------------------------------------------------------------------------- 8.2 c/w z junction temperature ----------------------------------------------------------------------------------------------------- 150 c z lead temperature (soldering, 10 sec.) ------------------------------------------------------------------------------- 260 c z storage temperature range -------------------------------------------------------------------------------------------- ? 65 c to 150 c z esd susceptibility (note 3) hbm (human body mode) ---------------------------------------------------------------------------------------------- 2kv mm (ma chine mode) ------------------------------------------------------------------------------------------------------ 200v recommended operating conditions (note 4) z junction temperature range -------------------------------------------------------------------------------------------- ? 40 c to 125 c z ambient temperature range -------------------------------------------------------------------------------------------- ? 40 c to 85 c parameter symbol test conditions min typ max unit input pow er supply input supply voltage v in 2.8 -- 5.5 v v uvlo_r -- -- 2.4 v under voltage lockout threshold v uvlo_f 1.8 -- -- mv quiescent current of x1 mode i qx1 x1 mode(led1~3 connect to v in ) -- 1 -- ma quiescent current of x2 mode i qx2 x2 mode no load -- 3 -- ma shutdown current i sh dn en = 0v, v in = 5v -- 1 11 ua led current i led accuracy i led-err 100% setting ? 8 -- +8 % current matching i led-led-err 100% setting ? 5 -- +5 % charge pump oscillator frequency f os c -- 1000 -- khz x1 mode to x2 mode transition voltage v ts v f = 3.5v, i out = 60ma v in falling -- 3.6 -- v protection over voltage protection v ovp open circuit at any led pin -- 5.5 -- v (v in = 3.6v, c in = c out = 2.2uf, c fly = 1uf, v f = 3.5v, i led1 = i led2 = i led3 = 20ma, esr = 0.03 , t a = 25 c, unless otherwise specified). to be continued
RT9363A 6 ds9363a-03 april 2011 www.richtek.com note 1. stresses listed as the above "absolute maximum ratings" may cause permanent damage to the device. these are for stress ratings. functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. note 2. ja is measured in the natural convection at t a = 25 c on the high effective thermal conductivity four layers thermal test board of jedec 51-7 thermal measurement standard. the case point of jc is on the expose pad. note 3. devices are esd sensitive. handling precaution is recommended. note 4. the device is not guaranteed to function outside its operating conditions. parameter symbol test conditions min typ max unit digital input logic-high v en_h 1.5 -- -- en threshold voltage logic-low v en_l -- -- 0.4 v logic-high i en_ h v en = v in -- 1 7 en current logic-low i en_ l v en = 0v -- 0.1 -- ua en low to shutdown delay t shdn refer to figure 5 2 -- -- ms en high time for dimming t hi refer to figure 5 0.5 -- -- us en high time for holding t lo refer to figure 5 0.5 -- 500 us
RT9363A 7 ds9363a-03 april 2011 www.richtek.com typical operating characteristics efficiency vs. input voltage 0 10 20 30 40 50 60 70 80 90 100 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 input voltage (v) efficiency (%) led v f = 3.2v led current vs. input voltage 10 12 14 16 18 20 22 24 26 2.8 3.2 3.6 4 4.4 4.8 5.2 5.6 input voltage (v) led current (ma) led v f = 3.2v led3 led1 led2 x2 mode led current vs. temperature 16 17 18 19 20 21 22 23 24 -40-30-20-10 0 102030405060708090 temperature led current (ma) v in = 3.2v led2 led1 led3 ( c) x1 mode led current vs. temperature 16 17 18 19 20 21 22 23 24 -40-30-20-10 0 102030405060708090 temperature led current (ma) v in = 4.0v led2 led1 led3 ( c) x1 mode quiescent current vs. temperature 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.6 -40-30-20-100 102030405060708090 temperature quiescent current (ma) v in = 3.5v ( c) x2 mode quiescent current vs. temperature 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 -40-30-20-10 0 102030405060708090 temperature quiescent current (ma) v in = 3.5v ( c)
RT9363A 8 ds9363a-03 april 2011 www.richtek.com v in = 3.7v x1 mode dimming operation time (5ms/div) en (2v/div) i led (10ma/div) v in = 3.7v v in = 3.3v x2 mode inrush current response cn (2v/div) time (250us/div) v out (1v/div) en (5v/div) i in (100ma/div) x1 mode inrush current response cn (2v/div) time (250us/div) v out (1v/div) en (5v/div) i in (100ma/div) frequency vs. temperature 0 200 400 600 800 1000 1200 -40-30-20-10 0 102030405060708090 temperature frequency (khz) v in = 3.5v ( c) shutdown current vs. temperature 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 -40-30-20-10 0 102030405060708090 temperature shutdown current (ua) v in = 3.5v ( c) v in = 3.3v x2 mode ripple voltage v in (50mv/div) time (2.5us/div) v out (50mv/div) cn (2v/div) i led (20ma/div)
RT9363A 9 ds9363a-03 april 2011 www.richtek.com application information the RT9363A uses a fractional switched capacitor charge pump to power up to three white leds with a programmable current. the part integrates current sources and automatic mode selection charge pump. it maintains the high efficiency by utilizing an x1/x2 fractional charge pump and current sources. the small equivalent x1 mode open loop resistance and ultra-low dropout voltage of current source extend the operating time of x1 mode and optimize the efficiency in white led applications. the operating voltage range is from 2.8v to 5.5v. internal soft start circuitry effectively reduces the in-rush current while both start-up and mode transition. the load is disconnected from v in while shutdown and the shutdown current is less than 1ua. high efficiency x1/x2 charge pump before the discussion of efficiency in RT9363A, two things need to be illustrated. one is the li-ion battery life time, the other is the forward voltage of white led. the li-ion battery energy is not linearly proportion to battery voltage. in the figure 6, it shows the 80% battery life of li-ion is arranged from 3.65v to 4.0v. the other voltage range occupies less than 20% battery energy and is insignificant. in the backlight application, the forward voltage of white leds most likely falls in 3.2 to 3.5v @i led = 20ma. the developing concept of rt9363 is based on the backlight application with li-ion battery. RT9363A is very cost-effective product for white leds backlight driving. it extends the 80% battery life by the reduction of open loop resistance at x1 mode and current source drop out voltage. figure 7 is the efficiency diagram of rt9363 and 80% battery life is marked by red rectangle. the RT9363A maximize the x1 mode operating range in the 80% battery life. therefore, the efficiency is not significant different to that without x1.5 mode charge pump. the peak efficiency of RT9363A is 93% and the average is 84%. comparing to the led drivers with x1.5 mode, only 1 to 2% efficiency loss by x2 mode. (assume 5% battery life in charge pump mode and the efficiency difference of x1.5 and x2 modes is 25%, the efficiency loss thus is 5%x25% = 1.25%). protection the RT9363A includes a soft start circuit to limit the inrush current at power on and mode transition. soft start circuit holds the input current level long enough for output capacitor c out reaching a desired voltage level. when the soft start off, the RT9363A won't sink spike current from v in . an over voltage protection function protect the output voltage from dangerous high voltage. the ovp turns off charge pump when the voltage difference between v in and v out is over the designed target. led current setting in backlighting part, an internal r set is used to set the initial current (20ma) of white led and implements a 4-bit dac for brightness control. users can easily configure the led current by a serial pulse. the dimming of white leds' current can be achieved by applying a pulse signal to the en pin. there are totally 16 steps of current could be set by users. an automatic r set selection is implemented in this part. RT9363A can automatically select the internal or external r sets by the connection of iset pin. the led current can be calculated by the following equation. where v set = 1.1v (typ.) and r set is the external resistor connected from iset pin to gnd. set led set v i = 276 r ?? ?? ?? r set led current (m a) 10k 30.3 12.1k 25.1 15k 20.2 20k 15.2 30.1k 10.1 led current setting table
RT9363A 10 ds9363a-03 april 2011 www.richtek.com pcb board layout the exposed pad, gnd pad should be connected to a strong ground plane for heat sinking and noise prevention. the traces running from pins to flying capacitor should be short and wide to reduce parasitic resistance and prevent noise radiation. output capacitor must be placed close to the vout and connect to gnd plane. input capacitor must be placed close to the vin and connect to gnd plane. c fly led3 led2 led1 cn cp gnd vin vout en iset 9 8 7 9 1 2 3 4 5 10 gnd r set c out c in all the traces of led and vin running from chip to leds should be wide and short to reduce the parasitic connection resistance and shielded, isolated by ground plane. the anodes of leds must connect to c in , not battery directly. figure 8. pcb layout guide figure 7. efficiency of RT9363A. (i led = 60ma, v f = 3.5v) led efficiency vs. v in 40 50 60 70 80 90 100 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0 4.2 4.4 v in (v) efficiency (%) figure 6. li-ion battery energy capacity versus battery voltage. capacity (mah) battery voltage (v) 4.2 4.0 3.65 50 650 80% battery life typical operation as shown in the typical application circuit, the power of the RT9363A is provided from the external adapter or battery. when en pin is low, the white led for backlighting is turned off and draws a very low current from battery supply. when en pin is high, RT9363A provides a twice mode load switch (x1) and high efficiency (x2) charge pump device intended for white led backlight applications. to maximize the power conversion efficiency, an internal sensing circuit monitors the voltage required on each constant sink input and sets the load switch and charge pump modes based on the input battery voltage and the current sink input voltage. RT9363A provides the option to control the 16-steps brightness of white leds with a digital pulse signal applied to en pin and the detailed timing of pulse dimming is shown in figure 5. capacitors selection to get the better performance of RT9363A, the selection of peripherally appropriate capacitor and value is very important. these 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 reduce 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 applications, the input voltage ripple is more important than the output ripple. input ripple is controlled by input capacitor c in , increasing the value of input capacitance can further reduce the ripple. practically, the input voltage ripple depends on the power supply's impedance. tantalum capacitors are not recommended for the RT9363A. if tantalum must capacitors are needed, c in and c fly must larger than 10 f and 1 f. because tantalum capacitors' values are less than normal when using for high frequency applications. so tantalum capacitor values and ceramic capacitor values can't be the same. but c out can't use tantalum capacitor, because during the x2 mode charge pump the v out is negative voltage.
RT9363A 11 ds9363a-03 april 2011 www.richtek.com information that is provided by richtek technology corporation is believed to be accurate and reliable. richtek reserves the ri ght to make any change in circuit design, specification or other related things if necessary without notice at any time. no third party intellectual property infringemen t of the applications should be guaranteed by users when integrating richtek products into any application. no legal responsibility for any said applications is assumed b y richtek. richtek technology corporation headquarter 5f, no. 20, taiyuen street, chupei city hsinchu, taiwan, r.o.c. tel: (8863)5526789 fax: (8863)5526611 richtek technology corporation taipei office (marketing) 5f, no. 95, minchiuan road, hsintien city taipei county, taiwan, r.o.c. tel: (8862)86672399 fax: (8862)86672377 email: marketing@richtek.com outline dimension dimensions in millimeters dimensions in inches symbol min max min max a 0.700 0.800 0.028 0.031 a1 0.000 0.050 0.000 0.002 a3 0.175 0.250 0.007 0.010 b 0.180 0.300 0.007 0.012 d 2.950 3.050 0.116 0.120 d2 2.300 2.650 0.091 0.104 e 2.950 3.050 0.116 0.120 e2 1.500 1.750 0.059 0.069 e 0.500 0.020 l 0.350 0.450 0.014 0.018 w-type 10l dfn 3x3 package 1 1 2 2 note : the configuration of the pin #1 identifier is optional, but must be located within the zone indicated. det ail a pin #1 id and tie bar mark options d 1 e a3 a a1 d2 e2 l b e see detail a

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