MP3021 1x, 1.5x, 2x auto-adjust charge pump white led backlight driver MP3021 rev. 1.0 www.monolithicpower.com 1 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. the future of analog ic technology description the MP3021 is a wled driver that can drive up to 4 backlight wleds at up to 30ma each. backlight brightness is adjusted using a 5-bit register plus one bit for precise low brightness control. the MP3021 employs a super efficient inductorless charge pump with 1x, 1.5x and 2x automatic mode control to achieve high efficiency power conversions. monolithic power system?s single wire mpc tm serial data link provides a simple and fast interface used to enable, disable and set current levels for each led. in addition, soft-start limits the inrush current during startup and mode switching. each output is current limited, providing controlled brightness and short circuit protection. thermal shutdown protection guards against excessive temperatures due to circuit loads and shorts. the tiny 3mm x 3mm qfn 16-pin package and small external capacitors deliver the most compact white led solution available. features ? backlight: up to 4 wleds at 30ma each ? single wire serial bus (mpc tm serial data link) simple, low overhead solution fast data transfer rate ? good current matching at low led current ? thermal shutdown protection ? under-voltage protection ? available in a 3mm x 3mm 16-pin qfn package ? low emi noise applications ? cellular phones ? pda phones ? pdas ? other small portable displays ?mps? and ?the future of analog ic technology? are registered trademarks of monolithic power systems, inc. ?mpc? is a trademark of monolithic power systems, inc. typical application MP3021 led0 led1 led2 led3 cp 16 15 14 13 1 vin c1a c1b c2a c2b data iset vss 7 4 3 6 2 8 11 5 batt single pin serial port d1 d2 d3 d4 120ma total backlight common anode configuration 100 90 80 70 60 50 40 30 20 efficiency (%) 2.5 3.0 3.5 4.0 4.5 battery voltage (v) efficiency vs battery voltage i_led=30ma i_led=20ma i_led=10ma
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 2 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. package reference top view exposed pad connect to pin 5 pin 1 id cp c2b c1b c1a nc iset nc nc 1 2 3 4 13 14 15 16 8 7 6 5 data vin c2a vss led3 led2 led1 led0 12 11 10 9 part number* package temperature MP3021dq qfn16 (3mm x 3mm) ?40 c to +85 c * for tape & reel, add suffix ?z (eg. MP3021dq?z) for rohs compliant packaging, add suffix ?lf (eg. MP3021dq?lf?z) absolute maxi mum ratings (1) all other pins.............................. ?0.3v to +6.5v junction temperature...............................150c lead temperature ....................................260c storage temperature ..............?65c to +150c supply voltage vin ........................... 2.5v to 6v operating temperature .............?40c to +85c recommended operating conditions (2) supply voltage v in .......................... 2.7v to 5.5v operating temperature .............?40c to +85 c thermal resistance (3) ja jc qfn16 (3mm x 3mm) ............. 60 ...... 12... c/w notes: 1) exceeding these ratings may damage the device. 2) the device is not guaranteed to function outside of its operating conditions. 3) measured on approximately 1? square of 1 oz copper. electrical characteristics v in = 4.2v, t a = +25 c, unless otherwise noted. parameter symbol condition min typ max units input supply voltage v in 2.7 5.5 v supply current i in 1x mode; i led ea = 20ma 83.6 ma supply current shutdown i in shdn v data = 0v 0.1 1.0 a current matching (4) i led match i led = 20ma 1.5 3.0 % data voltage, high v data (high) 1.2 v data voltage, low v data (low) 0.4 v data pin leakage i data v data = 5v -1.0 +1.0 a data acceptance pulse width t dapw 1.5 3.5 s data stop pulse width t dspw 8 s charge pump frequency f cp v in = 3.3v 1.0 1.25 1.5 mhz voltage of iset v iset 1.25 v hc/lc = 0, r1=4.17k ? 30 ma backlight led current for each led i bl hc/lc = 1, r1=6.25k ? 2 2.2 ma hc/lc = 0, r1=6.25k ? 20 22 ma thermal shutdown (5) t s 150 c note: 4) current matching definition: (max ? min)/(max + min) 5) guaranteed by design.
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 3 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. pin functions pin # name description 1 cp charge pump bypass for common anode vers ion. connect a 1f bypass capacitor to gnd. 2 c2b charge pump capacitor #2 negative node. co nnect the negative side of the #2 charge pump capacitor to c2b. 3 c1b charge pump capacitor #1 negative node. co nnect the negative side of the #1 charge pump capacitor to c1b. 4 c1a charge pump capacitor #1 positive node. connect the positive side of the #1 charge pump capacitor to c1a. typical applications require c1 to be 1f. 5 vss battery power gro und. connect the exposed pad to this pin. 6 c2a charge pump capacitor #2 positive node. connect the positive side of the #2 charge pump capacitor to c2a. typical applications require c2 to be 1f. 7 vin battery power input. connect the 2.5v to 5. 5v input source between batt and gnd. bypass batt to gnd with a 1f or greater capacitor. 8 data data input and single pin serial port for control of all functions. see part description. an external pill-down resistor with a typical value of 100k ?
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 4 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. typical performanc e characteristics v batt = 4.2v, t a = +25 c, unless otherwise noted. 100 90 80 70 60 50 40 30 20 efficiency (%) 2.5 3.0 3.5 4.0 4.5 battery voltage (v) efficiency vs battery voltage i_led=30ma i_led=20ma i_led=10ma 2.50 3.50 4.50 5.50 60 40 20 0 -20 -40 led current deviation (lc) vs battery voltage 1.00 0.50 0.00 -0.50 -1.00 led current (ma) 2.50 3.50 4.50 5.50 battery voltage (v) battery voltage (v) led current deviation (hc) vs battery voltage 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 led current (ma) bright level led current (lc) over 32 brightness levels 35 30 25 20 15 10 5 0 led current (ma) 0 5 10 15 20 25 30 bright level led current (hc) over 32 brightness levels 0 5 10 15 20 25 30 led3 led3 led1 led4 led2 led2 led1 led4 100 90 80 70 60 50 40 30 20 10 efficiency (%) 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 battery voltage (v) efficiency with different led voltage vf=3.4v vf=3.3v vf=3.2v i_led=20ma
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 5 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. typical performanc e characteristics (continued) v batt = 4.2v, t a = +25 c, unless otherwise noted. data 2v/div. i bat 50ma/div. cp 2v/div. i bat 100ma/div. cp 2v/div. i bat 100ma/div. cp 2v/div. soft start to 1x mode v in = 4.2v,1x mode, 4 led full brightness data 2v/div. soft start to 1.5x mode v in = 3.5v, 1.5x mode, 4 led full brightness data 2v/div. soft start to 2x mode v in = 2.7v, 2x mode, 4 led full brightness cp 2v/div. c1a 2v/div. c1b 2v/div. mode change from 1x to 1.5x v in = 3.3v,4 led full brightness cp 2v/div. c1a 2v/div. c1b 2v/div. mode change from 1.5x to 2x v in = 2.7v, 4 led full brightness c1a 2v/div. 400 n s/div. charge pump waveform at 1.5x mode v in = 3.06v, 4 led full brightness, 1.5x mode 400 n s/div. charge pump waveform at 2x mode v in = 3.06v, 4 led full brightness, 2x mode i bat 100ma/div. i bat 100ma/div. c1b 2v/div. c2a 2v/div. c2b 2v/div. c1a 2v/div. c1b 2v/div. c2a 2v/div. c2b 2v/div.
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 6 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. block diagram timer block enable logic overtemp det underv det serial data link bg iset brightness control / iref setting soft start / ramp controller 1.2 mhz osc current sources x4 (led) fault led0 led1 led2 led3 var charge pump (switches, control, crivers) control block 3-bit sm data vin vss c1a c1b c2a c2b cp figure 1?functional block diagram
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 7 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. operation the MP3021 uses a charge pump architecture optimized to support white led backlight driver needs. to maximize power efficiency, it automatically switches between 1x, 1.5x, and 2x modes. the device provides regulated current for up to four backlight leds. the charge pump automatically responds to changing conditions such as supply voltage, forward diode voltage and mode selection in order to maintain led current and maximize efficiency. the single pin interface provides on/off control, individual wled selection, and brightness control for the backlight. a 5-bit backlight brightness register provides 32 levels of current (brightness) control. iset controls the maximum brightness of the backlights. furthermore, the MP3021 is equipped with a low brightness backlight mode where the backlight current can be accurately set down to 100a. soft-start and mode changes limit the inrush current in the MP3021. the MP3021 uses charge pump derating over a period of 200s to limit inrush current. before startup the part checks for a shorted charge pump and pre-charges its capacitors. this further prevents inrush and over-current situations. single pin serial port operation the data pin acts as a single wire port for sending brightness data, led selection and led control to the MP3021. the mpc tm protocol is very flexible and easy to use and is based entirely on short and long pulses (see table1). short pulses having a width within the specified range are accepted as data. polarity of the data matches the pulse polarity. long pulses having a pulse width greater than the minimum specified serve two purposes in the communication. first, they are used to separate two similar data values. for example, back-to- back ?1? data must be separated by a long low pulse otherwise a ?0? would be seen between. similarly, back-to-back ?0?s must be separated by a long high. second, long pulses are used to indicate end of communication by sending two back-to-back long pulses. any number of bits up to a maximum of 11 can be entered during one communication, always starting with bit 0. the register value will not change until new input is received or the register is reset. table 1?mpc? pulse detail parameter minimum maximum note tshort 1.5s 3.5s accepted pulse tlong 8s na ignored pulse 1 begin on first acceptable pulse data line tshort send pattern <11010010101> end on back-to-back long pulse 10 0 0 0 0 111 1 tlong tlong tlong tlong tshort tshort tshort tshort tshort tshort tshort tshort tshort tshort figure 2?protocol waveforms
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 8 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. 0 on/off bit 1-bit 1-bit 2-bits 2-bits 5-bits hc/lc bit led sel bits mode bits brightness bits 12345678910 <0> off <1> on <0> high current <1> low current <23> <00> all on <11> 1 led on <10> 2 leds on <01> 3 leds on <45> <00> bl only <10> not allowed <01> not allowed <11> not allowed <678910> <00000> 1 x max brightness / 32 <10000> 2 x max brightness / 32 <01000> 3 x max brightness / 32 <11000> 4 x max brightness / 32 . . . . . . <11111> max brightness figure 3?control register control register definition the control register is as follows: ? bit 0 is the enable bit and determines whether the part is active or in shutdown ? bit 1 allows the part to be put into a low current mode ? bits 2-3 control which backlight wled pins are active ? bits 4-5 control the mode [bl=backlight]. always set b4b5 = <00> ? bits 6-10 control the brightness. step size and max brightness depend on r1 and bit1. bit 6 is the lsb. ? default is all ?0? and the register is reset only upon power up. shutdown setting the data-bit low [data:0] causes shutdown. during shutdown, the charge-pump output is switched to vss through a weak path. the supply current will be less than 1 a in shutdown. soft-start during startup and mode switching, an internal soft-start prevents excessive input current thus preventing excessive loading of the battery or input power source. setting the backlight led current the full-scale backlight led regulation current is set through the resistor r1 (refer to the typical application circuit on page 1). the voltage across r1 is fixed at 1.25v, and the internal current gain (i led /i r1 ) is set at 100. choose r1 for the desired full-scale led current according to the equation: max i 1ma k 125 r1 ? = where r1 is in k ? , and i led is in ma. suitable values for r1 are greater than 4.17k ? . the exact led current between 0 and the max set by r1 is determined by the brightness code and the hc/lc bit. the hc/lc bit allows for fine control at low current settings. the following table and graph exhibit the possible settings for a r1 of 4.17k ? .
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver MP3021 rev. 1.0 www.monolithicpower.com 9 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. table 2?setting backlight led current 5-bit brightness code i led (ma) hc/lc = 0 i led (ma) hc/lc = 1 0 0.94 0.09 1 1.88 0.19 2 2.81 0.28 3 3.75 0.38 4 4.69 0.47 5 5.63 0.56 6 6.56 0.66 7 7.50 0.75 8 8.44 0.84 9 9.38 0.94 10 10.31 1.03 11 11.25 1.13 12 12.19 1.22 13 13.13 1.31 14 14.06 1.41 15 15.00 1.50 16 15.94 1.59 17 16.88 1.69 18 17.81 1.78 19 18.75 1.88 20 19.69 1.97 21 20.63 2.06 22 21.56 2.16 23 22.50 2.25 24 23.44 2.34 25 24.38 2.44 26 25.31 2.53 27 26.25 2.63 28 27.19 2.72 29 28.13 2.81 30 29.06 2.91 31 30.00 3.00 figure 4?brightness control cp pin do not drive or force cp as it may be shorted to ground or pumped down by the controller in the MP3021 at any time. excessive capacitance on the cp node can cause the internal controller to time out before the charge pump can be ready. missing the timeouts will cause excessive pumping and a loss of efficiency. the MP3021 requires c1 and c2 be of the same value and type.
MP3021 ? 1x, 1.5x, 2x auto-adjust char ge pump wled backlight driver notice: the information in this document is subject to change wi thout notice. users should warra nt and guarantee that third party intellectual property rights are not infringed upon w hen integrating mps products into any application. mps will not assume any legal responsibility for any said applications. MP3021 rev. 0.1 www.monolithicpower.com 10 11/21/2007 mps proprietary information. unaut horized photocopy and duplication prohibited. ? 2007 mps. all rights reserved. package information qfn16 (3mm x 3mm) side view top view 1 16 13 12 9 8 5 4 bottom view 2.90 3.10 1.50 1.80 2.90 3.10 1.50 1.80 0.50 bsc 0.18 0.30 0.80 1.00 0.00 0.05 0.20 ref pin 1 id marking 1.70 0.50 0.25 recommended land pattern 2.90 note: 1) all dimensions are in millimeters. 2) exposed paddle size does not include mold flash. 3) lead coplanarity shall be 0.10 millimeter max. 4) drawing conforms to jedec mo-220, variation veed-4. 5) drawing is not to scale. pin 1 id see detail a pin 1 id option a 0.30x45? typ. pin 1 id option b r0.20 typ. detail a pin 1 id index area 0.70 0.30 0.50
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