MAX8625A_0812 Datasheet, PDF (1/16 Pages) Maxim Integrated Products – High-Efficiency, Seamless Transition, Step-Up/Down DC-DC Converter

19-1006; Rev 3; 12/08
EVAALVUAAILTAIOBNLEKIT
High-Efficiency, Seamless Transition,
Step-Up/Down DC-DC Converter
General Description
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
components. A 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 Shutdown^TM, 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.
Applications
PDAs and Smartphones
DSCs and Camcorders
MP3 Players and Cellular Phones
Battery-Powered Hard Disk Drive (HDD)
Pin Configuration
TOP VIEW
Features
♦ 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
Ordering Information
PART
PIN-
PACKAGE
TOP MARK
MAX8625AETD+
14 TDFN-EP**
(3mm x 3mm)
ABQ
Note: The device is specified over the -40°C to +85°C extended
temperature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
**EP = Exposed pad.
Typical Operating Circuit
14 13 12 11 10 9 8
INPUT
2.7V TO 5.5V
LX1
IN
LX2
OUT
OUTPUT
3.3V
MAX8625A
+
EP
1234567
EP = EXPOSED PAD.
TDFN-EP
PWM
SKIP
ON
OFF
GND
MAX8625A ^FB
SKIP
REF
ON
*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.