19-1724; Rev 2; 4/07
KIT
ATION
EVALU
BLE
AVAILA
4A, Low-Noise, High-Frequency,
Step-Up DC-DC Converter
General Description
Features
♦
On-Chip 10A Power MOSFET
♦
5V, 4A Output from a 3.3V Input
♦
Fixed 3.3V or 5V Output Voltage or
Adjustable (2.5V to 5.5V)
♦
Input Voltage Range Down to 0.7V
♦
Low Power Consumption
1mW Quiescent Power
1µA Current in Shutdown Mode
♦
Low-Noise, Constant Frequency Operation
(600kHz)
♦
Synchronizable Switching Frequency
(350kHz to 1000kHz)
MAX1709
The MAX1709 sets a new standard of space savings for
high-power, step-up DC-DC conversion. It delivers up
to 20W at a fixed (3.3V or 5V) or adjustable (2.5V to
5.5V) output, using an on-chip power MOSFET from a
+0.7V to +5V supply.
Fixed-frequency PWM operation ensures that the
switching noise spectrum is constrained to the 600kHz
fundamental and its harmonics, allowing easy postfilter-
ing for noise reduction. External clock synchronization
capability allows for even tighter noise spectrum con-
trol. Quiescent power consumption is less than 1mW to
extend operating time in battery-powered systems.
Two control inputs (ONA,
ONB)
allow simple push-on,
push-off control through a single momentary pushbut-
ton switch, as well as conventional on/off logic control.
The MAX1709 also features programmable soft-start
and current limit for design flexibility and optimum per-
formance with batteries.
The MAX1709 is supplied in both a high-power TSSOP
package, which allows a 10A
RMS
switch current and a
4A output, and a narrow SO package, which supplies a
2.4A output with a switch rated at 6A
RMS
. Although the
narrow SO device has a lower RMS switch rating, it has
the same peak switch current rating as the TSSOP
device, and so can supply 4A loads intermittently. If
loads of 2A or less are required, refer to the MAX1708.
Ordering Informations
PART
MAX1709ESE
MAX1709EUI+
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
16 Narrow SO
28 TSSOP-EP*
+Indicates
lead(Pb)-free/RoHS-compliant package.
*Exposed
pad.
________________________Applications
Routers, Servers, Workstations, Card Racks
Local 2.5V to 3.3V or 5V Conversion
Local 3.3V to 5V Conversion
3.6V or 5V RF PAs in Communications Handsets
TOP VIEW
ONA 1
LX 2
LX 3
LX 4
LX 5
LX 6
LX 7
Pin Configurations
28 ONB
27 CLK
26 3.3/5
Typical Operating Circuit
INPUT
1V TO 5V
1μH
OUTPUT
3.3V, 5V,
OR ADJ
UP TO 4A
MAX1709
25 NC
24 NC
23 PGND
22 PGND
21 PGND
20 PGND
19 PGND
18 PGND
17 NC
16 FB
15 OUT
LX 8
NC 9
NC 10
GND 11
SS/ILM 12
REF 13
OFF ON
SYNC
OR
INTERNAL
ONA
MAX1709
CLK
SS/LIM
REF
LX
GND
OUT
GND 14
TSSOP-EP*
Pin Configurations continued at end of data sheet.
________________________________________________________________
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.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
