The ADM8828/ADM8829 is a charge-pump voltage inverter that can be used to generate a negative supply from a positive input. Input voltages ranging from +1.5 V to +5.5 V can be inverted into a negative –1.5 V to –5.5 V output supply. This inverting scheme is ideal for generating a negative rail in single power-supply systems.
The ADM8828/ADM8829 is a charge‑pump voltage inverter that converts a positive input (1.5 V to 5.5 V) to a negative output (‑1.5 V to ‑5.5 V). It requires only two external capacitors and offers up to 25 mA output current with greater than 99 % voltage‑conversion efficiency. A dedicated shutdown pin reduces quiescent current to 20 nA when not in use.
The device is supplied in a 6‑lead SOT‑23 (RT‑6) package and is specified for industrial temperature ranges (‑40 °C to +85 °C). Detailed electrical specifications, pin functions, ordering information, and typical performance curves are provided in the document.
| Input Voltage | 1.5 V to 5.5 V |
|---|---|
| Supply Current (quiescent, unloaded) | 600 pA to 1000 pA |
| Output Current | 25 mA |
| Output Ripple | 25 mV p‑p (L=5 mA) |
| Charge‑Pump Frequency | 50 kHz to 190 kHz |
| Power Efficiency | 90 % (typical) |
| Voltage Conversion Efficiency | 99.5 % to 99.96 % |
| Shutdown Supply Current | 0.02 pA to 2 pA |
| Shutdown Input Voltage | 2.0 V (high disabled, low enabled) |
| Shutdown Exit Time | 175 µs |
Only two small external capacitors are needed for the charge‑pump operation.
The ADM8828 is available in a 6‑lead SOT‑23 (RT‑6) package.