The MAX1806 is a low-dropout linear regulator that operates from a +2.25V to +5.5V supply and delivers a guaranteed 500mA load current with a low 175mV dropout. The high-accuracy (±1%) output voltage is preset at an internally trimmed voltage (see Selector Guide) or can be adjusted from +0.8V to +4.5V with an external resis- tive-divider. An internal PMOS pass transistor allows low 210µA supply current, making this device ideal for portable equipment such as personal digital assistants (PDAs), cellular phones, cordless phones, and other equip- ment, including base stations and docking stations. Other features include an active-low, power-OK output that indicates when the output is out of regulation, a 0.02µA shutdown mode, short-circuit protection, and thermal shutdown protection. The MAX1806 comes in a miniature 1.3W, 8-pin power-µMAX package with a metal pad on the underside of the package.
The MAX1806 is a low‑dropout linear regulator designed for portable equipment such as PDAs, cellular phones and other battery‑powered devices. It operates from a 2.25 V to 5.5 V supply and delivers a guaranteed 500 mA load current with a typical dropout of 175 mV.
The device features an active‑low Power‑OK output, a 0.02 µA shutdown current, short‑circuit and thermal overload protection, and is offered in an 8‑pin Power‑UMAX package with an exposed thermal pad for efficient heat dissipation.
| Input Voltage Range | 2.25‑5.5 V |
|---|---|
| Adjustable Output Voltage Range | 0.8‑4.5 V |
| Dropout Voltage at 500 mA | 175 mV |
| Maximum Output Current | 500 mA |
| Ground‑Pin (Quiescent) Current | 210 µA |
| Shutdown Supply Current | 0.02 µA |
| Thermal Shutdown Temperature | 170 °C |
| Package | 8‑Pin Power‑UMAX (1.3 W) with exposed thermal pad |
| Power‑OK Output | Active‑low indicator of out‑of‑regulation condition |
The MAX1806 can supply up to 500 mA of continuous output current.
The typical dropout voltage is 175 mV when delivering 500 mA.
In shutdown, the device draws only 0.02 µA of supply current.
Thermal shutdown occurs when the junction temperature reaches 170 °C.