The TPS6512x DC-DC converter supplies all three voltages required by amorphous-silicon (a-Si) and low-temperature poly-silicon (LTPS) TFT-LCD displays. The compact layout of the TPS6512x uses a single inductor to generate independently-regulated positive and negative outputs. A free-running variable peak current PWM control scheme time-multiplexes the inductor between outputs. This control architecture operates at a pseudo-fixed-frequency to provide fast response to line and load transients while maintaining a relatively constant switching frequency and high efficiency over a wide range of input and output voltages. Due to the high switching frequency capability of the device, inexpensive and ultra-thin 8.2 or 10 μH inductors can be used.
The main output, VMAIN, is post-regulated to provide a low-ripple source drive voltage for the LCD display. The auxiliary outputs generate a boosted output voltage, VGH, up to 20 V, and a negative output voltage, VGL, down to -18 V for the LCD gate drive. The device has internal current limiting for high reliability under fault conditions. Additionally, the device offers a fixed output linear regulator for the LCD logic circuitry.
Feature
- Main Output, VMAIN
- Adjustable Voltage, 3.0 V to 5.6 V/25 mA
- Post-Regulated for Low Ripple (5mVPP)
- ±0.8% Typical Accuracy
- Efficiency up to 83%
- Positive Output, VGH
- Adjustable Voltage up to 20 V/2 mA
- ±3% Typical Accuracy
- Negative Output, VGL
- Adjustable Voltage down to -18 V/2 mA
- ±3% Typical Accuracy
- Auxiliary 1.8 V/3.3 V Linear Regulator
- Automatic or Programmable Power Sequencing
- Complete 1 mm Component Profile Solution
- 2.5 V to 5.5 V Input Voltage Range
- Output Short Circuit Protected
- 16-Pin QFN Package (3 × 3 × 0,9 mm)
- APPLICATIONS
- Small Form Factor a-Si and LTPS TFT LCD
- Cell Phones, Smart Phones
- PDAs, Pocket PCs
- Portable DVD
- Digital-Still Cameras, Camcorders
- Handheld Instruments
- Portable GPS
- Car Navigation Systems
