The REG103 is a family of low-noise, low-dropout, linear regulators with low ground pin current. Its new DMOS topology provides significant improvement over previous designs, including low-dropout voltage (only 115mV typ at full load), and better transient performance. In addition, no output capacitor is required for stability, unlike conventional low-dropout regulators that are difficult to compensate and require expensive low ESR capacitors greater than 1µF. Typical ground pin current is only 1mA (at IOUT = 500 mA) and drops to 0.5µA in not enabled mode. Unlike regulators with PNP pass devices, quiescent current remains relatively constant over load variations and under dropout conditions. The REG103 has very low output noise (typically 33µVrms for VOUT = 3.3V with CNR = 0.01µF), making it ideal for applications requiring high precision and low noise.
The REG103 family from Texas Instruments provides low‑noise, low‑dropout regulation for portable and battery‑powered devices. Its DMOS topology delivers an ultra‑low dropout voltage of 115 mV typ at 500 mA and 3.3 V output, while maintaining high accuracy (+2 % max) and low output noise (33 µVrms). The device includes features such as foldback current limit, thermal protection, an error‑flag output, and is available in small surface‑mount packages (SO‑8, DDPAK‑5, SOT223‑5).
The datasheet details absolute maximum ratings, electrical characteristics, pin configurations, typical performance curves, mechanical dimensions, and ordering information. It also outlines application areas such as portable communications, PDAs, modems, barcode scanners, and backup power supplies.
| Dropout Voltage (typ) | 115 mV at 500 mA, 3.3 V output |
|---|---|
| Output Noise | 33 µVrms |
| Accuracy | +2 % max |
| Ground Pin Current (typical) | 1 mA at 500 mA load |
| Thermal Shutdown Temperature | 150 °C |
| Available Packages | SO‑8, DDPAK‑5, SOT223‑5 |
The REG103 has a typical dropout voltage of 115 mV under those conditions.
No, the REG103 does not require a minimum output capacitor for stability.
It includes foldback current limit, thermal protection, and an error‑flag output indicating regulation status.
The regulator is available in SO‑8, DDPAK‑5, and SOT223‑5 surface‑mount packages.