MAX639
PRODUCTION5V/3.3V/3V Adjustable, High-Efficiency, Low-IQ, Step-Down DC-DC Converters
Low Supply Current, High-Efficiency Over Wide Load Range
- Part Models
- 6
- 1ku List Price
- Starting From $5.85
Overview
- High Efficiency for a Wide Range of Load Currents
- 10µA Quiescent Current
- Output Currents Up to 225mA
- Preset or Adjustable Output Voltage:
- 5.0V (MAX639)
- 3.3V (MAX640)
- 3.0V (MAX653)
- Low-Battery Detection Comparator
- Current-Limiting PFM Control Scheme
The MAX639/MAX640/MAX653 step-down switching regulators provide high efficiency over a wide range of load currents, delivering up to 225mA. A current-limiting pulse-frequency-modulated (PFM) control scheme gives the devices the benefits of pulse-width-modulated (PWM) converters (high efficiency at heavy loads), while using only 10µA of supply current (vs. 2mA to 10mA for PWM converters). The result is high efficiency over a wide range of loads.
The MAX639/MAX640/MAX653 input range is 4V to 11.5V, and the devices provide lower preset output voltages of 5V, 3.3V, and 3V, respectively. Or, the output can be user-adjusted to any voltage from 1.3V to the input voltage.
The MAX639/MAX640/MAX653 have an internal 1A power MOSFET switch, making them ideal for minimum-component, low- and medium-power applications. For increased output drive capability, use the MAX649/MAX651/MAX652 step-down controllers, which drive an external P-channel FET to deliver up to 5W.
Applications
- 5V to 3.3V Conversion
- 9V Battery to 5V, 3.3V, or 3V Conversion
- High-Efficiency Linear Regulator Replacement
- Portable Instruments and Handy-Terminals
Documentation
Data Sheet 1
Design Note 1
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.
| Part Model | Pin/Package Drawing | Documentation | CAD Symbols, Footprints, and 3D Models |
|---|---|---|---|
| MAX639CPA+ | Plastic Dual-In-Line, Narrow (0.3in) | ||
| MAX639CSA+ | Small-Outline IC Narrow (0.15in) | ||
| MAX639CSA+T | Small-Outline IC Narrow (0.15in) | ||
| MAX639EPA+ | Plastic Dual-In-Line, Narrow (0.3in) | ||
| MAX639ESA+ | Small-Outline IC Narrow (0.15in) | ||
| MAX639ESA+T | Small-Outline IC Narrow (0.15in) |
| Part Models | Product Lifecycle | PCN |
|---|---|---|
|
Jun 2, 2023 - 2361E WAFER FAB |
||
| MAX639CSA+ | PRODUCTION | |
| MAX639CSA+T | PRODUCTION | |
| MAX639ESA+ | PRODUCTION | |
| MAX639ESA+T | PRODUCTION | |
|
Oct 30, 2020 - 1702R2 ASSEMBLY |
||
| MAX639CSA+ | PRODUCTION | |
| MAX639CSA+T | PRODUCTION | |
| MAX639ESA+ | PRODUCTION | |
| MAX639ESA+T | PRODUCTION | |
|
Apr 20, 2026 - 2571A PIN/ERRATA |
||
| MAX639CSA+T | PRODUCTION | |
| MAX639ESA+T | PRODUCTION | |
This is the most up-to-date revision of the Data Sheet.
Software Resources
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| Parts | Product Life Cycle | Description |
|---|---|---|
| Switching Regulators & Controllers 1 | ||
| MAX649 | Obsolete | 5V/3.3V/3V or Adjustable, High-Efficiency, Low-IQ, Step-Down DC-DC Controllers |