max1626/max1627 are step-down dc-dc switching controllers from texas instruments. they provide high efficiency over loads ranging from 1ma to more than 2a. the output voltage is preset at 5v or 3.3v for the max1626 and adjustable for the max1627. input voltages can be up to 16.5v. the max1626/max1627 are functional upgrades for the max1649/max1651.
The MAX1626/MAX1627 controllers provide high efficiency over a wide load range (1 mA‑2 A) using a current‑limited pulse‑frequency‑modulated (PFM) scheme and up to 100 % duty cycle. They drive an external P‑channel MOSFET, allowing designs up to 12 W or higher with low dropout voltage and reduced component count.
Typical applications include portable computers, PDAs, handheld devices, and other battery‑powered equipment. The datasheet details pin functions, electrical characteristics, typical circuits, and design guidelines for both fixed‑output (MAX1626) and adjustable‑output (MAX1627) versions.
| Input Voltage Range (V+) | 3.0 V – 16.5 V |
|---|---|
| Maximum Input Voltage | 16.5 V |
| Output Voltage (MAX1626) | 5 V or 3.3 V (fixed) |
| Output Voltage (MAX1627) | Adjustable |
| Switching Frequency | up to 300 kHz |
| Efficiency | >90 % (3 mA‑2 A loads) |
| Maximum Duty Cycle | 100 % |
The devices operate from 3.0 V to 16.5 V on the V+ pin.
The MAX1626 provides a fixed 5 V or 3.3 V output selected by the 3/5 pin.
The MAX1627 uses an external resistor divider on the FB pin to set an adjustable output voltage.
They can switch at frequencies up to 300 kHz.