Dual-rail AMOLED bias supply in a 3 mm × 3 mm package
The Texas Instruments TPS65631DPDR is a dual-output DC-DC converter purpose-built for powering AMOLED display panels. It delivers a fixed 4.6 V positive rail and a programmable negative rail adjustable from -1.4 V down to -4.4 V, covering the bias requirements of most small-to-medium AMOLED panels used in smartphones, wearables, and portable instruments. The input voltage range of 2.9 V to 4.5 V is directly compatible with a single-cell Li-ion battery, so the part fits designs where the display bias must be generated from the system battery without an intermediate boost stage.
What the two output rails mean for the AMOLED BOM
AMOLED panels need a positive source voltage (typically 4.6 V) for the pixel-drive TFTs and a negative bias voltage (adjustable between -1.4 V and -4.4 V) for the cathode and gate-off drive. The TPS65631DPDR integrates both rails in one IC, saving the board area and inductor count that a discrete positive-plus-negative converter pair would require. The negative output is adjustable — a resistor divider sets the exact voltage within the -1.4 V to -4.4 V window, letting the designer tune the panel bias for optimal contrast and gate-off margin without changing the IC.