低功耗、三输出TFT LCD DC-DC转换器
说明The MAX1779 triple-output DC-DC converter provides highly efficient regulated voltages required by small active matrix, thin-film transistor (TFT) liquid-crystal displays (LCDs). One high-power DC-DC converter and two low-power charge pumps convert the +2.7V to +5.5V input supply voltage into three independent output voltages.
The primary high-power DC-DC converter generates a boosted output voltage (VMAIN) up to 13V that is regulated within ±1%. The low-power BiCMOS control circuitry and the low on-resistance (1 ohm) of the integrated power MOSFET allows efficiency up to 91%. The 250kHz current-mode pulse-width modulation (PWM) architecture provides fast transient response and allows the use of ultra-small inductors and ceramic capacitors.
The dual charge pumps independently regulate one positive output (VPOS) and one negative output (VNEG). These low-power outputs use external diode and capacitor stages (as many stages as required) to regulate output voltages up to +40V and down to -40V. A proprietary regulation algorithm minimizes output ripple, as well as capacitor sizes for both charge pumps.
The MAX1779 is available in the ultra-thin TSSOP package (1.1mm max height).
- Three Integrated DC-DC Converters
- 250kHz Current-Mode PWM Boost Regulator
- Up to +13V Main High-Power Output
- ±1% Accuracy
- High Efficiency (91%)
- Dual Charge-Pump Outputs
- Up to +40V Positive Charge-Pump Output
- Down to -40V Negative Charge-Pump Output
- Internal Supply Sequencing
- Internal Power MOSFETs
- +2.7V to +5.5V Input Supply
- 0.1µA Shutdown Current
- 0.5mA Quiescent Current
- Internal Soft-Start
- Power-Ready Output
- Ultra-Small External Components
- Thin TSSOP Package (1.1mm max)