MAXIM MAX639 MAX640 MAX653 5V 3.3V 3V Adjustable, High-Efficiency, Low IQ, Step-Down DC-DC Converters Data Manual User Guide
Summary
Optimize your circuit design with the MAX639, MAX640, or MAX653 low-power step-down DC-DC converters. These high-efficiency regulators provide stable voltage conversion at preset outputs (down to 3V) while maintaining an ultra-low quiescent current draw of just 10µA. This technical guide provides comprehensive details on electrical characteristics, pin configurations, and absolute maximum ratings, making it essential for engineers developing minimum-component-count portable instruments and battery-powered electronics.
Page 1 Text Content
查询MAX639供应商 19-4505; Rev 3; 8/97 /M /M EVALUATION KIT INFORMATION INCLUDED
5V/3.3V/3V/Adjustable, High-Efficiency, Low IQ, Step-Down DC-DC Converters
_______________General Description ____________________________Features The MAX639/MAX640/MAX653 step-down switching High Efficiency for a Wide Range of Load Currents regulators provide high efficiency over a wide range of
10µA Quiescent Current
load currents, delivering up to 225m A. A current-limiting pulse-frequency-modulated (PFM) control scheme gives
Output Currents Up to 225m A
the devices the benefits of pulse-width-modulated
(PWM) converters (high efficiency at heavy loads), while Preset or Adjustable Output Voltage:
using only 10µA of supply current (vs. 2m A to 10m A for 5.0V (MAX639) PWM converters). The result is high efficiency over a 3.3V (MAX640) wide range of loads.
3.0V (MAX653)
The MAX639/MAX640/MAX653 input range is 4V to
Low-Battery Detection Comparator
11.5V, and the devices provide lower preset output volt-
ages of 5V, 3.3V, and 3V, respectively. Or, the output Current-Limiting PFM Control Scheme
can be user-adjusted to any voltage from 1.3V to the input voltage. The MAX639/MAX640/MAX653 have an internal 1A power ______________Ordering Information MOSFET switch, making them ideal for minimum-compo-
nent, low- and medium-power applications. For increased PART TEMP. RANGE PIN-PACKAGE
output drive capability, use the MAX649/MAX651/MAX652 MAX639CPA 0°C to +70°C 8 Plastic DIP step-down controllers, which drive an external P-channel
MAX639CSA 0°C to +70°C 8 SO
FET to deliver up to 5W.
MAX639C/D 0°C to +70°C Dice* MAX639EPA -40°C to +85°C 8 Plastic DIP
________________________Applications
MAX639ESA -40°C to +85°C 8 SO
9V Battery to 5V, 3.3V, or 3V Conversion MAX639MJA -55°C to +125°C 8 CERDIP
High-Efficiency Linear Regulator Replacement Ordering Information continued on last page. * Contact factory for dice specifications.
Portable Instruments and Handy-Terminals 5V-to-3.3V Converters
__________Typical Operating Circuit __________________Pin Configuration
INPUT TOP VIEW
5.5V TO 11.5V
OUTPUT 5V
VOUT SHDN
LBO MAX639
MAX639
MAX640
ON/OFF SHDN VOUT
LBI MAX653
LOW-BATTERY
LBILOW-BATTERY GND LX
LBO DETECTOR
DETECTOR
INPUT OUTPUT
DIP/SO
VFB GND
Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468.
Page Summary Contents For MAXIM MAX639 MAX640 MAX653 5V 3.3V 3V Adjustable, High-Efficiency, Low IQ, Step-Down DC-DC Converters Data Manual User Guide
Manual Details
| Brand | IQ |
|---|---|
| Pages | 12 |
| File Size | 161.91 KB |
| Published | May 24, 2026 |
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Frequently Asked Questions
What is the required inductor value for safe operation?
The peak inductor current must be limited to 600mA using an inductor of 100µH or greater.
What is the adjustable output voltage range?
The output can be adjusted to any voltage from 1.3V up to the input voltage (V_in).
What is the maximum operational current?
These step-down controllers deliver a high current of up to 225mA.