View SP6682ER-L_9088585.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

1 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation sp6682 features ideal for white led driver low profile, inductorless regulator x1.5 and x2 modes for highest efficiency +2.7v to +5.5v input voltage range fast turn-on time, 175 s 1ma quiescent current <1.5 a shutdown current built-in 600khz oscillator programmable output current or voltage pwm dimming control with enable pin shutdown to disconnect output from input soft start to eliminate in-rush current industry standard 10-pin msop package and small 10-pin dfn package high efficiency charge pump regulator f or white leds applications next generation mobile phones pdas 3.3v to 5.0v conversion digital still cameras digital camcorders palmtop computers color lcd modules description the sp6682 is a current regulated charge pump ideal for converting a li-ion battery input for driving white led used in backlighting color displays. the charge pump automatically switches between x1.5 and x2 modes based on the input voltage, providing improved efficiency over traditional methods using charge pump doubler followed by ldo. this input voltage threshold can be externally programmed for optimized efficiency at specific output voltages and currents. the sp6682 operates with an internal 600khz clock, enabling the use of small external components. output current or voltage can be accurately regulated by modulating the switcher between the charge pump and output capacitor. in shutdown mode, the ic disconnects the output from the input and draws less than 1.5 a current. the sp6682 is offered in a 10-pin msop package, and a small 10-pin dfn package. typical application schematic sp6682 v out c1p v in v mode fb c2p c1n gnd c2n en/pwm 1 2 3 4 5 10 9 8 7 6 c2 2.2 f c4 2.2 f c5 2.2 f r6 20 c1 2.2 f lithium-ion enable/pwm dimming white led c3 0.1 f r2 r1 r3 1m 20 20 20 2.7 - 4.2v c6 0.1 f now available in lead free packaging sp6682 10 pin dfn 10 9 8 7 6 1 2 3 4 5 c2p c1n gnd c2n en/pwm v out c1p v in v mode fb
2 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation parameter min typ max units conditions input voltage 2.7 5.5 v quiescent current 1.2 3 ma v in = 4.2v, v out = 3.6v, i out = 100 a shutdown current 1.5 a en/pwm = 0v, v in = 5.5v oscillator frequency 0.42 0.60 0.78 mhz v in = 3.6v v fb reference voltage 0.275 0.306 0.337 v charge pump output 11 18 ? fb = 0v, v in = 3.6v, resistance i out = 20ma, v mode = high v mode threshold voltage 1.15 1.25 1.35 v v in falling @ 25 c hysteresis for mode transition 30 mv pp v in = 3.6v @ 25 c voltage v mode pin current 0.01 0.5 av mode = 1.25 en/pwm logic low 0.4 v en/pwm logic high 1.6 v en/pwm pin current 0.01 0.5 av en/pwm = 4.2v fb pin current 0.5 av fb = 1v v out turn-on time 175 500 sv in = 3.6v, fb within 90% regulation electrical characteristics unless otherwise specified: v in =+2.7v to +5.0v, c1=c2=c4=c5=2.2 f (ceramic, esr=0.03 ? ), c3=0.1 f (ceramic) and t amb =-40 c to +85 c unless otherwise noted. v in , v mode , v out and en/pwm ................. -0.3v to 6v v in - v out ........................................................... 0.7v output current (i out ) ...................................... 300ma power dissipation per package - 10-pin msop (derate 8.84mw/ c above +70 c) ................. 720mw junction temperature .................................... +125 c storage temperature ...................... -65 c to +150 c esd rating. ................................................ 2kv hbm these are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. absolute maximum ratings
3 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation v out 306m en/pw 1.25v c2n start-up and charge pump switches v mode c2p c1p fb mode control gnd v in c1n 600 khz clock manager v oltage referenc mode comp v out comp functional diagram pin description pin number pin name description 1v out regulated charge pump output. 2 c1p positive terminal to the charge pump flying capacitor c2. 3v in input pin for the 2.7v to 5.5v supply voltage. 4v mode charge pump mode program pin. when v mode is greater than 1.25v, x1.5 charge pump is used. otherwise, charge pump switches to x2 mode. a voltage divider shown in typical application circuit programs the v in threshold for charge pump mode switching. 5f b this is the feedback pin for output current or voltage regulation. the voltage of this pin is compared with an internal 306mv reference. 6 en/pwm enable and pwm dimming control input. pull this pin low to discon- nect v out from v in and shutdown the sp6682. 7 c2n negative terminal to the charge pump flying capacitor, c4. 8 gnd ground reference. 9 c1n negative terminal to the charge pump flying capacitor, c2. 10 c2p positive terminal to the charge pump flying capacitor c4.
4 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation performance characteristics refer to the typical application circuit, t amb = 25 c, i o = 60ma unless otherwise specified. en/pwm v out 5v/div 1v/div v in v out 50mv/div 50mv/div 0 10 20 30 40 50 60 70 80 90 2.7 3 3.3 3.6 3.9 4.2 input voltage(v) efficiency (%) 0.26 0.27 0.28 0.29 0.3 0.31 0.32 0.33 0.34 2.7 3 3.3 3.6 3.9 4.2 v in (v) v fb (v) v out 50mv/div 50mv/div v in 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 2.7 3 3.3 3.6 3.9 4.2 v in (v) i supply (ma) figure 1. output voltage turn-on time figure 2. power efficiency vs. input voltage figure 3. x2 mode voltage ripple when v in = 2.7v figure 4. feedback pin voltage vs. input voltage figure 5. x1.5 mode voltage ripple when v in = 3.3v figure 6. quiescent current vs. input voltage
5 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation 0 1 2 3 4 5 6 2.7 3 3.3 3.6 3.9 4.2 input voltage (v) brightness (kcd/m2) 4 led's @ 30ma 4 led's @ 15ma performance characteristics: continued refer to the typical application circuit, t amb = 25 c, i o = 60ma unless otherwise specified. 0 1 2 3 020406 080 100 duty cycle,% brigtness, kcd/m2 100 hz 500 hz general overview the sp6682 is a current regulated charge pump ideal for converting a li-ion battery input for driving white leds used in backlighting color displays in cellular phones, pdas, digital cam- eras and mp3 players. the sp6682? propri- etary autoboost feature enables the ic to auto- matically transition from x1.5 boost mode to x2 boost mode based on battery input voltage for optimal efficiency and performance. the sp6682 is able to efficiently drive up to six 20ma white leds in parallel and maintain a constant brightness over a very wide operating voltage range (2.7v to 5.5v). the sp6682 oper- ates with an internal 600khz clock, enabling the use of small external components. other fea- tures of sp6682 include pwm dimming control as well as complete input/out disconnect in shutdown. in shut down mode the ic draws less than 1.5 a current. the output regulation is achieved by sensing the voltage at the feedback pin and modulating the switcher between the charge pump and output capacitor. theory of operation the sp6682 regulated charge pump block dia- gram consists of four main blocks (voltage reference, mode control, clock manager, start- up and charge-pump switches) and two com- parators (v mode comparator and v out com- parator). 1) voltage reference. this block provides the 306mv and 1.25v reference voltages needed for the two comparators. 2) mode control. an external voltage divider connected to the v mode pin will define an input voltage to the mode comparator which sets the logic state of the mode selection outputs to the x2 or x1.5 modes. v mode is compared to a 1.25v bandgap voltage. for example, if one makes a 158k/100k divider, the mode will change at 2.58 x 1.25 v =3.23v. a comparator- based cycle by cycle regulation ensures that no mode change occurs during cycles. 3) clock manager. an internal 600 khz clock is generated in this block. depending on the mode control, the appropriate clock phasing is generated here and sent to the start-up and charge-pump switches block. 4) start-up and charge pump switches. dur- ing start-up, until the reference is established, this block keeps the charge pump inactive. dur- ing this period the output stays floating, by consequence the charge pump drivers are now referenced to v out . charging of the output will occur (e.g. when v in is ramped up to 4.2v, v out ramps only up to about 3v), but not to the value of v in , protecting the white led from experi- figure 7. brightness vs. input voltage figure 8. brightness vs duty cycle operation
6 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation encing high input voltages. another important operation of this block is the pwm/en dim- ming control, which is implemented in the delay of each pump driver, so that the enable high pulse width is proportional to the delay of the individual pump switches. 5) v out comparator and output control. a 306mv reference voltage is compared to feed- 1 8 5 rb sp6682 rb 2.2uf gnd fb v out figure 9. driving discrete white leds as current source configuring the sp6682 as voltage or current source the white led load configuration used by customers can be discrete white leds or a white led module. inside the white led module, there may or may not be resistors in series with the white leds. according to the different application requirements, the sp6682 can be configured as either a voltage source or a current source to provide solutions for these different applications, as shown in figure 9~12. figure 9 shows using the sp6682 to drive discrete white leds as a current source. the current in one white led current is set by the ratio of the feedback pin voltage (306mv) and the bias resistor r b . to set the operating current, r b can be selected by: r b = v fb i led 3-wire w-led module anode fb gnd fig 10. 3-wire white led module the current of the remaining white leds is set according to the similarity of the white leds. 3- wire white led module with internal series resistors as shown in figure 10 can also be driven in this way. gnd v out anode 5 v fb rb sp6682 cathode 8 2-wire w-led module 1 figure 11. driving 2-wire white led module as current source operation: continued back output voltage to control the vout needed for the application. output current is set by a bias resistor from fb pin to gnd pin chosen by the relationship: i out = v fb r fb where v fb = 306mv. in figure 11, sp6682 was used to drive a 2-wire white led module without internal series resis- tors as a current source. the bias resistor r b is selected to regulate the total current of the white led module instead of the current of single led as in figure 9. application information
7 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation in this application, the bias resistor can be se- lected by: r b = v fb i led (total) where i led(total) is the total operating current of all the white leds. to use sp6682 as a voltage source for fixed voltage applications, a voltage divider is need to program the ouput voltage, as shown in figure 12. the output voltage is set by the ratio of the two anode 5 8 sp6682 cathode v out r6 1 r5 2.2uf v fb 2-wire w-led module gnd figure 12. driving 2-wire white led module as voltage source resistors and the feedback control voltage as shown by: v out = ( 1 + r 5 ) ?v fb r 6 programming the operating mode sp6682 can automatically change from x1.5 mode to x2 mode for highest efficiency. to use this feature, divider resistors should be chosen according to the specific application, as shown in figure 13. the guideline for divider resistor selections is as follows. for high input voltage, the sp6682 will work in x1.5 mode. when the input voltage drops to vth threshold voltage, it will switch to x2 mode automatically. the vth threshold volt- age for mode change can be calculated by: v th = (v f + 0.306 + m ?i led ?r out )/1.5 where v f and m are the forward voltage and number of the white leds, rout is the output resistance of the sp6682. the equation for the voltage divider r 1 and r 2 with v mode = 1.25v is: v th = 1.25v ?(1+r 1 /r 2 ) which can be expressed as r1: r 1 = (v th / 1.25 -1) ?r 2 for the typical sp6682 application, using v f =3.6v, m=4, i led =15ma, r out =16 ? , the v th will be 3.24v. select r 2 =100k ? , then r 1 =158k ? . capacitor selection ceramic capacitors are recommended for their inherently low esr, which will help produce low peak to peak output ripple, and reduce high frequency spikes. the fly capacitor controls the strength of the charge pump. selection of the fly capacitor is a trade-off between the output voltage ripple and the output current capability. decreasing the fly capacitor will reduce the output voltage ripple because less charge will be delivered to the output capacitor. however, smaller fly capaci- v in v in c2 gnd 4 v mode r1 sp6682 8 r2 3 figure 13. programming the vmode resistors application information: continued
8 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation tor leads to larger output resistance, thus de- creasing the output current capability and the circuit efficiency. place all the capacitors as close to the sp6682 as possible for layout. increasing the value of the input and output capacitors could further reduce the input and output ripple. refer to table 1 for some suggested low esr capacitors. manufacturers/ part number capacitance/ capacitor/ esr telephone# voltage size/type at 100khz tdk/847-803-6100 c2012x5r1a225k 2.2 f/10v 0805/x5r 0.030 ? tdk/847-803-6100 c2012x5r0j475k 4.7 f/6.3v 0805/x5r 0.020 ? murata/770-436-1300 grm188r60j225ke01d 2.2 f/6.3v 0603/x5r 0.030 ? murata/770-436-1300 grm219r60j475ke01d 4.7 f/6.3v 0805/x5r 0.020 ? brightness control using pwm dimming control can be achieved by applying a pwm control signal to the en/pwm pin. the brightness of the white leds is controlled by increasing and decreasing the duty cycle of the pwm signal. while the operating frequency range of the pwm control is from 60hz to 700hz, the recommended maximum brightness frequency range of the pwm signal is from 60hz to 200hz. a repetition rate of at least 60hz is required to prevent flicker. brightness matching for white leds, the forward voltage drop is a function of the operating current. however, for a given current, the forward voltage drops do not always match due to normal manufacturing tol- erance, thus causing uneven brightness of the white leds. in figure 14, assume high-precision bias resis- tors were used, the operating current ratio of two different branches can be easily derived as shown by: i 1 = v out - v f1 i 2 v out - v f2 where i 1 i 2 are the operating current of the white leds,v f1 ,v f2 are the forward voltage of the white leds. since the brightness of the white led is propor- tional to the operating current, for better bright- ness matching, a higher output voltage could be used. this could be done by using larger resis- tor, as shown in figure 14. rb2 is used to bias the operating current of the white led, rb1 is use to increase the output voltage. better brightness matching was achived at the cost of the power wasted on the bias resistor. rb1 8 v fb d1 rb dn gnd vfn vf1 v out 1 rb2 rb vf2 rb 5 d2 sp6682 i 1 i 2 i n figure 14. increasing brightness matching table: 1 suggested low esr capacitors power efficiency the efficiency of driving the white leds can be calculated by: = v f ?i f = v f ?i f v f v i ? i v i (n ?i f + i q )v i ?n application information
9 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation where v i , i i are input voltage and current v f , i f are the forward voltage and operating current of white leds i q is quiescent current, which is considered small compared with i f . n is the boost ratio (x1.5 or x2) sp6682 high voltage white led driver the sp6682 can also be configured as a high voltage boost converter to drive more than 10 white leds. figure 15 shows the schematic of this application as well as actual data showing efficiency of > 85%. by using an external induc- tor, mosfet and diode, high output voltage can be generated to drive 12 white leds (2 branches, each branch has 6 white leds in series). the current through the white leds is determined by: i led = v fb r 1 70 75 80 85 90 95 100 2.7 3.0 3.3 3.6 3.9 4.2 v in (v) efficiency (%) d11 x5r ceramic d3 sot23 r2 15 25v l1 lqh32cn4r7m11 4.7uh d12 d8 ds schottky mbr0530 d4 q1 ceramic en/pwm r1 15 d6 c1 10uf d9 d7 c3 x5r 2.2uf 25v d10 d2 r3 1m iled = vfb/r1 = 20ma sp6682 1 2 7 6 5 4 3 8 9 10 v out c1p c2n en/pwm fb v mode v in gnd c1n c2p d1 si1304 d5 v in: 2.7-4.2v figure 15. using sp6682 as a high voltage white led driver application information pinouts sp6682 10 pin dfn 10 9 8 7 6 1 2 3 4 5 c2p c1n gnd c2n en/pwm v out c1p v in v mode fb v out c1p v in v mode fb sp6682 10 pin msop 1 2 3 4 5 10 9 8 7 6 c2p c1n gnd c2n en
10 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation package: 10 pin msop 1 e1 e pin #1 indentifier must be indicated within this shaded area (d/2 * e1/2) l1 l r1 1 r 1 seating plane gauge plane l2 b b symbol min nom max a-- 1.1 a1 0 - 0.15 a2 0.75 0.85 0.95 b 0.17 - 0.27 c 0.08 - 0.23 d e e1 e e1 l 0.4 0.6 0.8 l1 l2 n-10 - r 0.07 - - r1 0.07 - - ?0o-8o ?1 0o - 15o note: dimensions in (mm) 10 pin msop jedec mo-187 (ba) variation 3.00 bsc 4.90 bsc 3.00 bsc 0.50 bsc 2.00 bsc 0.95 ref 0.25 bsc 1 2 e/2 e1 e d c with plating base metal b section b-b a2 a a1 b
11 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation package: 10 pin dfn symbol min nom max a 0.8 0.9 1 a1 0 0.02 0.05 a2 0.55 0.65 0.8 a3 b 0.18 0.25 0.3 d d2 2.2 2.7 e e e2 1.4 - 1.75 k 0.2 - - l 0.3 0.4 0.5 note: dimensions in (mm) 3x3 10 pin dfn jedec mo-229 (veed-5) variation 0.20 ref 3.00 bsc 3.00 bsc 0.5 pitch bottom view b e l k d2 e2 1 2 t op view d e e/2 d/2 a a3 a1 side view
12 date: 03/04/05 sp6682, high efficiency charge pump regulator for white leds ?copyright 2005 sipex corporation corporation analog excellence sipex corporation reserves the right to make changes to any products described herein. sipex does not assume any liability aris ing out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor t he rights of others. sipex corporation headquarters and sales office 233 south hillview drive milpitas, ca 95035 tel: (408) 934-7500 fax: (408) 935-7600 ordering information part number top mark operating temperature range package type sp6682eu ....................... sp6682eu....................................-40 c to +85 c ............................ 10 pin msop sp6682eu/tr ................. sp6682eu....................................-40 c to +85 c ............................ 10 pin msop sp6682er ...................... sp6682euryww.........................-40 c to +85 c ............................... 10 pin dfn sp6682er/tr ................. sp6682eryww...........................-40 c to +85 c ............................... 10 pin dfn /tr = tape and reel pack quantity is 2,500 for msop and 3,000 for dfn. available in lead free packaging. to order add "-l" suffix to part number. example: sp6682er/tr = standard; SP6682ER-L/tr = lead free click here to order samples

▲Up To Search▲

Price & Availability of SP6682ER-L

	To Download SP6682ER-L Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .