The MAX730A/MAX738A/MAX744A are 5V-output CMOS, step-down switching regulators. The MAX738A/ MAX744A accept inputs from 6V to 16V and deliver 750mA. The MAX744A guarantees 500mA load capability for inputs above 6V and has tighter oscillator frequency limits for low-noise (radio) applications. The MAX730A accepts inputs between 5.2V and 11V and delivers 450mA for inputs above 6V. Typical efficiencies are 85% to 96%. Quiescent supply current is 1.7mA and only 6µA 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. These regulators require only a single inductor value to work in most applications, so no inductor design is necessary. The MAX730A/MAX738A/MAX744A also feature cycle- by-cycle current limiting, overcurrent limiting, undervolt- age lockout, and programmable soft-start protection.
The MAX730A, MAX738A, and MAX744A are 5 V output CMOS step‑down switching regulators. They accept input voltages from 5.2 V‑11 V (MAX730A) or 6 V‑16 V (MAX738A/MAX744A) and deliver up to 750 mA of regulated output. Typical efficiencies range from 85 % to 96 % with low quiescent current (1.7 mA, 6 µA in shutdown). These devices are suited for portable instruments, cellular phones, radios, personal communicators, distributed power systems, and computer peripherals.
Key features include cycle‑by‑cycle current limiting, over‑current protection, undervoltage lockout, programmable soft‑start, and a fixed‑frequency PWM architecture that simplifies external component selection. The datasheet provides absolute maximum ratings, detailed electrical characteristics, pin configurations for multiple package types, and typical operating curves for efficiency, oscillator frequency, and transient response.
| Maximum output current (MAX738A/MAX744A) | 750 mA |
|---|---|
| Maximum output current (MAX730A) | 450 mA |
| Input voltage range (MAX730A) | 5.2 V – 11 V |
| Input voltage range (MAX738A/MAX744A) | 6 V – 16 V |
| Efficiency | 85 % – 96 % |
| Quiescent supply current | 1.7 mA (active), 6 µA (shutdown) |
| Oscillator frequency (MAX744A) | 159 kHz – 212.5 kHz |
| Package options | 8‑Pin DIP, 8‑Pin SO, 16‑Pin Wide SO, 8‑Pin CERDIP |
| Protection features | Cycle‑by‑cycle current limiting, over‑current limiting, undervoltage lockout, programmable soft‑start |
The MAX730A operates with input voltages from 5.2 V to 11 V.
In shutdown mode the device draws about 6 µA.
They include cycle‑by‑cycle current limiting, over‑current limiting, undervoltage lockout, and programmable soft‑start.