G2542 Global Mixed-mode Technology 6-Channels 40V White LED Driver with Boost Regulator Features General Description Wide 2.7V to 5.5V Input Supply Range 600KHz Fixed Frequency 40V/2A, 0.2Ω n-channel MOSFET Maximum Programmable LED Channel Current 30mA Current accuracy ±3% and current balance ±2% 100Hz~25kHz PWM Dimming PWM to DC Dimming Protection Input Under-Voltage Protection Over Current Protection Over Voltage Protection Thermal Protection RoHs Compliant TQFN4X4-20 Package The G2542 is a high-efficiency 6-channel white LED driver. It is designed for LCD panel that employs an LED array as the lighting source. An integrated switch current mode boost controller drives six strings in parallel and supports up to 10 pieces of LEDs per string. Applications The MODE pin in G2542 is used to set the dimming mode. If MODE pin set to floating, the dimming mode is in the PWM mode, the current driver ON/OFF is synchronized with the PWM signal. If Mode pin set to AGND, PWM and ILED current is set at PWM duty multiplied by ISET current when PWM duty ≥ 25%. If the PWM duty <25%, the ILED current is fixed at 0.25xISET, and the dimming duty is 4 x PWM duty. If MODE set to VDC, the dimming mode operated in the Pure DC mode, the current-source outputs are DC dimming and the PWM duty cycle modulates the amplitude of the currents. Open LED-string automatically disable the channel from entering over voltage protection. The G2542 automatically regulated supply voltage for the LED light bars without the need to calculate the output for different LED types. It also integrates a 40V n-channel MOSFET that provides high output power. The 6-channel current driver is ideal for constant current driving, 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 800 times of this reference current. A PWM pin can be used to perform PWM dimming from the range of 100Hz to 25kHz. UMPC and Notebook Computer Backlight Ordering Information ORDER NUMBER TEMP. RANGE G2542R91U 2542 PACKAGE (Green) PACKING -40°C to +85°C TQFN4X4-20 Note:R9: TQFN4X4-20 1: Bonding Code U: Tape & Reel Pin Configuration Typical Application Circuit L1 PWM LX OVP LX VDC COMP CVIN RVIN 1 NC 2 ISET 3 MODE AGND CVCC 14 PGND MODE 13 PGND PWM 4 12 OVP 5 11 CS1 EN G2542 COMP 10 LED3 ISET RISET TQFN4X4-20 LED1 LED2 CC1 CS2 8 9 CS3 CS4 7 6 RC1 CC2 CS5 COUT VDC LX Thermal Pad ROVP2 ROVP1 15 CS6 VOUT 40V MAX VIN VCC EN D1 VIN 16 17 18 19 20 VIN G2542 LED4 LED5 LED6 AGND PGND Note: Recommend connecting the Thermal Pad to the Ground for excellent power dissipation. TEL: 886-3-5788833 http://www.gmt.com.tw Ver: 0.2 Aug 12, 2013 1