MAX1626/MAX1627
EVALUATION KIT AVAILABLE
5V/3.3V or Adjustable,
100% Duty-Cycle, High-Efficiency,
Step-Down DC-DC Controllers
General Description
The MAX1626/MAX1627 step-down DC-DC controllers
operate over a 2.6V to 16.5V input voltage range. The
controllers deliver load current from 1mA to more than
2A. The MAX1626 has pin-selectable 3.3V and 5V out-
puts. The MAX1627 supports adjustable outputs from
1.3V to 16V.
A unique current-limited, pulse-frequency-modulation
(PFM) control scheme operates up to 100% duty cycle,
resulting in very low dropout voltage. This control
scheme eliminates minimum load requirements and
reduces supply current under light loads to 90µA
(versus 2mA to 10mA for common pulse-width modula-
tion controllers).
The devices are available in a 8-pin SOIC package
(-40°C to +85°C) and dice (0°C to +70°C).
Applications
• 5V to 3.3V Green PC Applications
• Battery-Powered Applications
• Handheld Computers
• High-Efficiency Step-Down Regulation
• Low-Cost Notebook Computer Supplies
• Minimum Component DC-DC Converters
• PCMCIA Power Supplies
• PDAs and Other Handheld Devices
• Portable Terminals
Pin Configuration
TOP VIEW
OUT 1
3/5 (FB) 2
SHDN 3
REF 4
MAX1626
MAX1627
8 GND
7 EXT
6 CS
5 V+
SO
( ) ARE FOR MAX1627
Benefits and Features
• Reduce External Components and Total Cost
• 300KHz PWM Switching Reduces Component Size
• Tiny Surface-Mount Inductor
• Reduce Power Dissipation
• > 90% Efficiency from 3mA to 2A Loads
• Low Dropout Voltage
• 100% Maximum Duty Cycle
• Reduce Number of DC-DC Controllers to Stock
• Wide 2.6V to 16.5V Input Voltage Options
• Selectable 3.3V and 5V or Adjustable 1.3V to 16V
Output Voltage Options
• Reduce System Power Consumption
• 90µA Max Quiescent Current
• 1µA Max Shutdown Current
• Operates Reliably in Adverse Environment
• Soft-Start Limits Startup Current
• Current-Limited Control Scheme
• Increase Design Flexibility
• External P-Channel MOSFET Allows Output Power
of > 12.5W
Ordering Information
PART
TEMP RANGE
MAX1626C/D
0°C to +70°C
MAX1626ESA
-40°C to +85°C
MAX1627C/D
0°C to +70°C
MAX1627ESA
-40°C to +85°C
* Dice are tested at TA = +25°C.
PIN-PACKAGE
Dice*
8 SO
Dice*
8 SO
Typical Operating Circuit
INPUT
3.3V to 16.5V
V+
MAX1626
ON/OFF
SHDN
CS
EXT
P
3/5
REF
OUT
GND
OUTPUT
3.3V
19-1075; Rev 1; 5/15