SKYA21004中文资料Three-Channel LCD Bias Power Management IC with Three-Channel High-Efficiency White LED Driver数据手册Skyworks规格书

描述 Description

Please note: this product is being discontinued and is not recommended for new designs.

The SKYA21004 consists of a power management blocksupplying LCD bias rails and a three-channel backlight driver.

The LCD bias power management block of the SKYA21004includes a boost converter that supplies main analog voltage(AVDD) of the panel, two charge-pump controllers supplying agate-on voltage (VGH), and a gate-off voltage (VGL) to the LCDpanel. The boost converter uses a 1.3-MHz fixed frequency togenerate AVDD voltage up to 14.5 V. Two charge-pumpcontrollers can generate up to +30 V and down to 30 V from thecharge-pump stages configured by diodes and capacitors. Aproprietary regulation algorithm can minimize the output ripple.

The backlight driver of the SKYA21004 integrates the boostconverter to drive the LED voltage up to 28 V. The switchingfrequency is adjustable from 600 kHz to 2 MHz for systemintegration flexibility, which optimizes the efficiency and controlsEMI. Three precision current sinks are programmable to drive LEDcurrent up to 120 mA per string.

The backlight driver of the SKYA21004 supports Analog PulseWidth Modulation (APWM) dimming, Direct Pulse WidthModulation (DPWM) dimming, and analog dimming (through I2C).

In the DPWM dimming mode, the output waveform follows theduty and the frequency of control input signal from the PWM pin.In the APWM dimming mode, the LED current of each channel iscontrolled by the input duty of PWM input signal, the I2Cprogrammed brightness level, and the external RISET resistor.

The PWM pin can accept the frequency range from 100 Hz to25 kHz with 10-bit resolution of duty control and 8-bit resolutionof current control. When the PWM pin is not used, it needs to bepulled high.

The SKYA21004 is available in a 7 mm  4 mm, 36-pin QFN package.

特性 Features

• LCD bias power (AVDD boost)
• Input supply range: 2.8 V to 5.5 V
• 1.3 MHz fixed frequency boost regulator
• Adjustable voltage up to 14.5 V (±1% typical accuracy)
• Short-circuit, over-voltage, and over-temperature protection