MAXIM new LED driver for large LCD panels

MAX17061 is the latest MAXIM high efficiency white light emitting diode (LED) driver, suitable for the use of LED array backlight large LCD panel (LCD). Switch current mode boost converter is used to drive the LED array, can drive up to 8 series parallel (each string can be connected to 10 LED) LED.

Switch current mode boost converter is used to drive the LED array, can drive up to 8 series parallel (each string can be connected to 10 LED) LED. Each string can achieve + 1.5% current regulation accuracy, to ensure uniform LED brightness. The MAX17061 has a wide input voltage range from 4.5V to 26V, and the LED current can be fixed to 25mA or adjusted in the 15mA to 30mA range.

MAX17061 generated by the internal DPWM signal, accurate control of the brightness of WLED. DPWM frequency can be set by resistors, the DPWM duty cycle is controlled by an external PWM signal or directly via the MAX17061 interface of the SMBUS. DPWM control provides 8-bit resolution throughout the dimming range and supports IntEL's low-power display energy saving technology (DPST), effectively extending battery life.

MAX17061 has many ways to protect the controller when the fault condition occurs. An independent feedback loop provides an output voltage limit in any case to ensure safe operation. Once the detection of a string of LED open circuit, can be banned from this string of LED work, while the other string LED to maintain normal work. MAX17061 also has LED short circuit detection, the short circuit of the LED string will be off after the 2ms fault shielding time. In order to maintain reliable operation, the controller also has the function of cycle by cycle current limiting and soft start. When the MAX17061 is in a current limit state, the boost converter is locked after an internal timeout period. Thermal shutdown circuitry provides another protection measure.

MAX17061 boost controller built in 150m (typ), 45V (max) power MOSFET, current sense amplifier supports precise cycle by cycle current limiting. This structure greatly simplifies the peripheral circuit and saves the PCB space. When the LED current is about 25mA, the feedback voltage of each series of LED is only 625mV (typical value), which helps to reduce power consumption and improve efficiency. MAX17061 has an optional switching frequency (500kHz, 750kHz or 1MHz), which can be optimized in terms of component size and operating frequency in different applications.

MAX17061 features a good heat dissipation 28 pin 4mm x 4mm thin QFN package.