The LTC1983-3 and LTC1983-5 are inverting charge pump DC/DC converters that produce negative regulated outputs. The parts require only three tiny external capacitors and can provide up to 100mA of output current. The devices can operate in open loop mode (creating a –VIN supply) or regulated output mode depending on the input supply voltage and the output current. The LTC1983-3/LTC1983-5 have many useful features for portable applications including very low quiescent current (25µA typical) and a zero current shutdown mode programmed through the SHDN pin. The LTC1983-3/LTC1983-5 are over-temperature and short-circuit protected. The parts are available in a 6-pin low profile (1mm) ThinSOT package.
The LTC1983‑3 and LTC1983‑5 are inverting charge‑pump DC/DC converters that generate regulated negative outputs of –3 V or –5 V. They are intended for portable equipment, LCD bias supplies, GaAs FET bias, and charge‑pump inverter applications, requiring only three external capacitors and delivering up to 100 mA of output current.
Key features include a low quiescent current of 25 µA, a 4 % output‑voltage accuracy, a 900 kHz internal oscillator, and built‑in short‑circuit and over‑temperature protection. The devices are supplied in a 6‑lead ThinSOT (1 mm) package and support both regulated and open‑loop operation modes.
| Fixed Output Voltages | -3 V (LTC1983‑3) / -5 V (LTC1983‑5) |
|---|---|
| Output Voltage Accuracy | ±4 % |
| Quiescent Current | 25 µA typical |
| Maximum Output Current | 100 mA |
| Operating Voltage Range | 2.3 V to 5.5 V |
| Oscillator Frequency | 900 kHz |
| Shutdown Input High Threshold | ≈1.4 V |
| Shutdown Input Low Threshold | ≈0.3 V |
| Package | 6‑lead Plastic SOT‑23 ThinSOT (1 mm) |
The device draws about 25 µA of quiescent current in normal operation.
The SHDN pin has a threshold of approximately 0.7 V; a low level shuts the device down.
Both parts are offered in a 6‑lead Plastic SOT‑23 ThinSOT package with a 1 mm profile.