The MAX1777/MAX1977/MAX1999 are dual step-down, switch-mode power-supply (SMPS) controllers that generate logic-supply voltages in battery-powered systems. These devices feature two pulse-width modulation (PWM) controllers, adjustable from 2V to 5.5V or fixed at 5V and 3.3V.
The MAX1777, MAX1977, and MAX1999 are dual step‑down, switch‑mode power‑supply controllers that generate logic‑supply voltages for battery‑powered systems. Each device includes two PWM controllers, adjustable or fixed 5 V and 3.3 V outputs, and always‑on linear regulators capable of 100 mA output current.
Key features include Maxim’s Quick‑PWM response without sense resistors, ultrasonic pulse‑skipping for low‑noise audio applications, selectable switching frequencies (200 kHz/5 V, 300 kHz/3.3 V for MAX1777; 400 kHz/5 V, 500 kHz/3.3 V for MAX1977), power‑good signaling, over‑voltage protection, and operation over –40 °C to +85 °C in a 28‑pin QSOP package.
| Operating Temperature Range | -40 °C to +85 °C |
|---|---|
| Always‑On Linear Regulator Output Current | Up to 100 mA |
| Switching Frequency (MAX1777) | 200 kHz @ 5 V, 300 kHz @ 3.3 V |
| Switching Frequency (MAX1977) | 400 kHz @ 5 V, 500 kHz @ 3.3 V |
| Package | 28‑pin QSOP |
They operate from –40 °C to +85 °C.
Each linear regulator can supply up to 100 mA.
The MAX1977 can run at 400 kHz for the 5 V output and 500 kHz for the 3.3 V output.