19-1006; Rev 0; 3/08
High-Efficiency, Seamless Transition,
Step-Up/Down DC-DC Converter
The MAX8625A PWM step-up/down regulator is intend-
ed to power digital logic, hard disk drives, motors, and
other loads in portable, battery-powered devices such
as PDAs, cell phones, digital still cameras (DSCs), and
MP3 players. The MAX8625A provides either a fixed
3.3V or adjustable output voltage (1.25V to 4V) at up to
0.8A from a 2.5V to 5.5V input. The MAX8625A utilizes
a 2A peak current limit.
Maxim’s proprietary H-bridge topology* provides a
seamless transition through all operating modes without
the glitches commonly seen with other devices. Four
internal MOSFETs (two switches and two synchronous
rectifiers) with internal compensation minimize external
www.DataScohmeepto4nUen.ctso.mA SKIP input selects a low-noise, fixed-
frequency PWM mode, or a high-efficiency skip mode
where the converter automatically switches to PFM
mode under light loads for best light-load efficiency.
The internal oscillator operates at 1MHz to allow for a
small external inductor and capacitors.
The MAX8625A features current-limit circuitry that shuts
down the IC in the event of an output overload. In addi-
tion, soft-start circuitry reduces inrush current during
startup. The IC also features True ShutdownTM, which
disconnects the output from the input when the IC is
disabled. The MAX8625A is available in a 3mm x 3mm,
14-pin TDFN package.
PDAs and Smartphones
DSCs and Camcorders
MP3 Players and Cellular Phones
Battery-Powered Hard Disk Drive (HDD)
♦ Four Internal MOSFET True H-Bridge Buck/Boost
♦ Glitch-Free, Buck-Boost Transitions
♦ Minimal Output Ripple Variation on Transitions
♦ Up to 92% Efficiency
♦ 37µA (typ) Quiescent Current in Skip Mode
♦ 2.5V to 5.5V Input Range
♦ Fixed 3.3V or Adjustable Output
♦ 1µA (max) Logic-Controlled Shutdown
♦ True Shutdown
♦ Output Overload Protection
♦ Internal Compensation
♦ Internal Soft-Start
♦ 1MHz Switching Frequency
♦ Thermal-Overload Protection
♦ Small 3mm x 3mm, 14-Pin TDFN Package
(3mm x 3mm)
Note: The device is specified over the -40°C to +85°C extended
+Denotes a lead-free package.
**EP = Exposed pad.
Typical Operating Circuit
14 13 12 11 10 9 8
2.7V TO 5.5V
EP = EXPOSED PAD.
*US Patent #7,289,119.
True Shutdown is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.