MAX5072 Datasheet, PDF (1/27 Pages) Maxim Integrated Products – 2.2MHz, Dual-Output Buck or Boost Converter with POR and Power-Fail Output

19-3503; Rev 2; 2/06
EVAALVUAAILTAIOBNLEKIT
2.2MHz, Dual-Output Buck or Boost
Converter with POR and Power-Fail Output
General Description
The MAX5072 is a dual-output DC-DC converter with inte-
grated high-side n-channel power MOSFETs. Each output
can be configured either as a buck converter or a boost
converter. The MAX5072 is designed to manage the
power requirements of xDSL modems. The wide 5.5V to
23V input voltage range allows for the use of inexpensive
AC adapters to power the device in xDSL modem appli-
cations. Each output is programmable down to 0.8V in the
buck mode and up to 28V in the boost mode with an out-
put voltage accuracy of ±1%. In the buck mode, convert-
er 1 and converter 2 can deliver 2A and 1A, respectively.
The output switching frequency of each converter can be
programmed from 200kHz to 2.2MHz to avoid harmonics
in the xDSL frequency band of operation. Each output
operates 180° out-of-phase, thus reducing input-capaci-
tor ripple current, size, and cost. A SYNC input facilitates
external frequency synchronization. Moreover, a CLKOUT
output provides out-of-phase clock signal with respect to
converter 2, allowing four-phase operation using two
MAX5072 ICs in master-slave configuration.
The MAX5072 includes an internal digital soft-start that
reduces inrush current, eliminates output-voltage over-
shoot, and ensures monotonic rise in output voltage dur-
ing power-up. The device includes a power-good output
and power-on reset as well as manual reset. In addition,
each converter output can be shut down individually. The
MAX5072 features a "dying gasp" output, which goes low
when the input voltage drops below a preprogrammed
voltage. Protection features include output short-circuit
protection for buck mode and maximum duty-cycle limit
for boost operation, as well as thermal shutdown.
The MAX5072 is available in a thermally enhanced 32-pin
thin QFN package that can dissipate 2.7W at +70°C ambi-
ent temperature. The device is rated for operation over the
-40°C to +85°C extended, or -40°C to +125°C automotive
temperature range.
Applications
xDSL Modems
xDSL Routers
Point-of-Load DC-DC Converters
Ordering Information
PART
TEMP RANGE
MAX5072ETJ -40°C to +85°C
*EP = Exposed pad.
PIN-PACKAGE
PKG
CODE
32 Thin QFN-EP*
(5mm x 5mm)
T3255-4
Features
♦ 4.5V to 5.5V or 5.5V to 23V Input Supply Voltage
Range
♦ 0.8V (Buck) to 28V (Boost) Output Voltage
♦ Two Independent Output DC-DC Converters with
Internal Power MOSFETs
♦ Each Output can be Configured in Buck or Boost
Mode
♦ I_OUT1 and I_OUT2 of 2A and 1A (Respectively) in
Buck Mode
♦ 180° Out-of-Phase Operation
♦ Clock Output for Four-Phase Operation
♦ Switching Frequency Programmable from 200kHz
to 2.2MHz
♦ Digital Soft-Start and Independent Converter
Shutdown
♦ SYNC Input, Power-On Reset, Manual Reset, And
Power-Fail Output
♦ Short-Circuit Protection (Buck)/Maximum Duty-
Cycle Limit (Boost)
♦ Thermal Shutdown
♦ Thermally Enhanced 32-Pin Thin QFN Package
Dissipates up to 2.7W at +70°C
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
PGOOD1 25
16 MR
SOURCE1 26
15 BYPASS
SOURCE1 27
14 VL
PGND 28
SGND 29
MAX5072
13 VL
12 V+
PGND 30
11 OSC
SOURCE2 31
10 PFI
SOURCE2 32
9 SYNC
12345678
Ordering Information continued at end of data sheet.
THIN QFN
________________________________________________________________ Maxim Integrated Products 1
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