The ADM8845 is a charge pump driver for LCD white LED backlights. It supports 6 LEDs, input voltage range is 2.6V to 5.5V, supports 3-fold, 1.5-fold, 1-fold fractional charge pump, and the maximum efficiency can reach 88%.
The ADM8845 charge‑pump driver provides regulated constant‑current drive for up to six LEDs used in LCD backlighting, camera flashes, and other white‑LED applications. It supports fractional charge‑pump modes (1×, 1.5×, 2×) to maximize power efficiency across the 2.6 V to 5.5 V input range, and includes digital control pins for shutdown and brightness adjustment.
The device is supplied in a 9 mm² (3 mm × 3 mm) LFCSP package with low‑power shutdown, soft‑start, and a feedback network that achieves 1 % LED current matching. Detailed specifications, pin functions, typical performance curves, and thermal characteristics are provided in the following sections.
| Input Voltage Range | 2.6 V – 5.5 V |
|---|---|
| Maximum LED Count | 6 LEDs |
| Charge Pump Frequency | 15 MHz |
| Power Efficiency | up to 88 % |
| LED Current (typical) | 30 mA |
| PWM Frequency Range | 0.1 kHz – 200 kHz |
The device operates from 2.6 V to 5.5 V supply voltage.
It can drive up to six LEDs for main and sub‑display backlighting.
The charge‑pump driver can achieve up to 88 % efficiency over the Li‑ion voltage range.
The datasheet specifies a typical LED current of 30 mA.