ver: 0.2 feb 16, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 1 G5524A global mixed-mode technology inc. integrated power supply for tft-lcd panels with 4-channel white led driver features ? 2.5v to 5.5v input supply range ? boost regulator ? 640khz/1.2mhz fixed frequency ? current-mode control ? fast transient response to pulse load ? 1% accurate output voltage ? built-in 20v/2a, 0.2 n-channel mosfet ? high efficiency up to 90% ? programmable soft-start ? over-current protection ? output under-voltage protection ? white-led driver ? wide 4.2v to 24v input supply range ? adjustable switching frequency ? 40v/2a, 0.3 n-channel mosfet ? input under-voltage protection ? over current protection ? over voltage protection ? maximum programmable led channel current 50ma ? maximum 3% matching between channels ? 100hz~20khz pwm dimming ? high-performance operational amplifiers ? 150ma output short-circuit current ? 12v/ s slew rate ? 12mhz, -3db bandwidth ? rail-to-rail input and output ? low dropout voltage linear regulator ? 350ma maximum output current ? adjustable output voltage ? on-chip gpm controller ? adjustable falling time and power-on delay ? flicker compensator ? power-on sequence control ? charge pump for vgh regulation ? low voltage detector ? programmable detecting voltage and delay time ? thermal protection ? rohs compliant ? tqfn5x5-40 and tqfn3.8x6.2-44 package applications ? notebook computer displays ? umpcs ? lcd monitor general description the G5524A includes a high-performance boost regulator, 4-channel led driver, a low dro pout linear regulator (ldo), a gate pulse modulator (gpm), a voltage detector, a vcom buffer (unity-gain opa), and a vgh charge pump controller for active-matrix thin-film trans istor (tft) liquid-crystal dis- plays (lcds). the boost converter provides the regulated supply volt- age for the panel source driver ics. the converter is a high switching frequency (640khz or 1.2mhz) cur- rent-mode regulator with an integrated 20v n-channel 0.2 mosfet that allows the us e of ultra-small inductors and ceramic capacitors. it prov ides fast transient re- sponse to pulsed loading while achieving efficiency over 90%. the device can produce output voltage as high as 18v from an input as low as 2.8v. soft-start is pro- grammed by external capac itor, which sets the in- put-current ramp-rate. the led driver automatically regulated supply voltage for the led light bars without t he need to calculate the output for different led types. a freq2 pin is applied to adjust switching frequency in the range of 640khz to 2mhz. it also integrates a 40v n-c hannel mosfet that provides high output power. the 4-channel current driver is ideal for constant current drivi ng, and, well matched less than 3%. to set the maximum driving current, the iset pin is used to determine reference current. each channel of the current drivers is set to 1300 times of this reference cur- rent. a pwm pin can be used to perform pwm dimming from the range of 100hz to 20khz. open led-string automatically disable the channel from entering over voltage protection. the low-dropout (ldo) linear regulator can supply up to 350ma current while input voltag e is 3.3v. it uses an inter- nal pmos as the pass device. it is suitable for the supply voltage of the timing controller. the gpm is controlled by frame signals from timing con- troller to modulate the gate-o n voltage, vghm, which acts a flicker compensation circuit to reduce the coupling effect between gate lines and pixels. it also can delay the gate-on voltage while power-on for achieving a corrected power-on sequence for gate driver ics. both of power-on delay time and the falling time of the gate-on voltage are programmable by external capacitor and resistor. the voltage detector monitors the supply voltage to issue a reset signal while the detec ted voltage is too low. the detecting level is decided by an external resistor divider and the delay time is programmable by an external ca- pacitor. the vcom buffer can drive the lcd vcom voltage that features high short-circuit curr ent (150ma), fast slew rate (12v/ s), wide bandwidth (12mhz) and rail-to-rail in- put/output. the vgh charge pump controlle r provides regulated tft gate-on voltage. the regulat ion of the positive charge pump is generated by the internal comparator that senses the output voltage and co mpares it with an internal refer- ence.
ver: 0.2 feb 16, 2011 tel: 886-3-5788833 http://www.gmt.com.tw 2 G5524A global mixed-mode technology inc. ordering information order number marking temp. range package (green) G5524Arg1u 5524 -40 c to 85 c tqfn5x5-40 G5524Ak41u 5524 -40 c to 85 c tqfn3.8x6.2-44 note: rg: tqfn5x5-40 k4: tqfn3.8x6.2-44 1: bonding code u: tape & reel pin configuration comp1 vin1 ldoi vdiv ss1 agnd1 freq2 en2 pwm vin2 lx2 re vghm vgh fbp ldoo adj fb1 freq1 pgnd lx1 vflk vdpm cd reset avdd opai opao led4 led3 led2 led1 ovp2 pgnd pgnd lx2 G5524A tqfn5x5-40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 thermal pad 30 29 28 27 26 25 24 23 22 21 40 39 38 37 36 35 34 33 32 31 agnd2 comp2 drvp iset note: recommend connecting the thermal pad to the ground for excellent power dissipation. thermal pad 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 35 34 33 32 31 30 29 28 27 26 25 24 23 44 43 42 41 40 39 38 37 36 pgnd pgnd lx1 vin1 ldoi vdiv ss1 comp1 agnd1 freq2 en2 pwm vin2 lx2 lx2 ovp2 led1 iset led2 led3 led4 agnd2 pgnd pgnd agnd1 comp2 opao opai avdd reset cd vdpm vflk re vghm agnd1 agnd1 vgh adj drvp fbp fb1 freq1 ldo0 G5524A tqfn3.8x6.2-44 (agnd) (pgnd) comp1 vin1 ldoi vdiv ss1 agnd1 freq2 en2 pwm vin2 lx2 re vghm vgh fbp ldoo adj fb1 freq1 pgnd lx1 vflk vdpm cd reset avdd opai opao led4 led3 led2 led1 ovp2 pgnd pgnd lx2 G5524A tqfn5x5-40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 thermal pad 30 29 28 27 26 25 24 23 22 21 40 39 38 37 36 35 34 33 32 31 agnd2 comp2 drvp iset note: recommend connecting the thermal pad to the ground for excellent power dissipation. thermal pad 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 35 34 33 32 31 30 29 28 27 26 25 24 23 44 43 42 41 40 39 38 37 36 pgnd pgnd lx1 vin1 ldoi vdiv ss1 comp1 agnd1 freq2 en2 pwm vin2 lx2 lx2 ovp2 led1 iset led2 led3 led4 agnd2 pgnd pgnd agnd1 comp2 opao opai avdd reset cd vdpm vflk re vghm agnd1 agnd1 vgh adj drvp fbp fb1 freq1 ldo0 G5524A tqfn3.8x6.2-44 (agnd) (pgnd)
|
