The MAX748A/MAX763A is a 3.3V output CMOS step-down switching regulator. The MAX748A accepts inputs from 3.3V to 16V and delivers up to 500mA. The MAX763A accepts inputs between 3.3V and 11V and delivers up to 500mA. Typical efficiencies are 85% to 90%. Quiescent supply current is 1.4mA (MAX763A), and only 0.2µA in shutdown. Pulse-width-modulation (PWM) current-mode control provides precise output regulation and excellent transient responses. Output voltage accuracy is guaranteed to be ±5% over line, load, and temperature variations. Fixed-frequency switching allows easy filtering of output ripple and noise, as well as the use of small external components. A 22µH inductor works in most applications, so no magnetics design is necessary. The MAX748A/MAX763A also feature cycle-by-cycle cur- rent limiting, overcurrent limiting, undervoltage lockout, and programmable soft-start protection. The MAX748A is available in 8-pin DIP and 16-pin wide SO packages; the MAX763A comes in 8-pin DIP and SO packages.
The MAX748A and MAX763A are CMOS step‑down switching regulators that convert an unregulated DC input to a regulated 3.3 V output. The MAX748A operates from 3.3 V to 16 V, while the MAX763A works from 3.3 V to 11 V, both providing up to 500 mA load current. They use current‑mode PWM control for precise regulation, fast transient response, and cycle‑by‑cycle current limiting.
Key features include high efficiency (85‑90%), low quiescent current (1.4 mA for MAX763A, 0.2 µA in shutdown), programmable soft‑start, over‑current and undervoltage lockout protection, and selectable 8‑pin DIP, 8‑pin SO, 16‑pin wide‑SO, or 8‑pin CERDIP packages. The datasheet provides absolute maximum ratings, electrical characteristics, pin descriptions, typical operating curves, and layout recommendations.
| Input Voltage Range (MAX748A) | 3.3 V to 16 V |
|---|---|
| Input Voltage Range (MAX763A) | 3.3 V to 11 V |
| Maximum Load Current | 500 mA |
| Efficiency | 85 % to 90 % |
| Quiescent Supply Current (MAX763A) | 1.4 mA |
| Shutdown Supply Current | 0.2 µA |
The MAX748A operates from 3.3 V up to 16 V.
Both devices can deliver up to 500 mA of load current.
Shutdown current is typically 0.2 µA.
They include cycle‑by‑cycle current limiting, over‑current limiting, undervoltage lockout, and programmable soft‑start.