MAX8529 Datasheet, PDF (1/21 Pages) Maxim Integrated Products – 1.5MHz Dual 180 Out-of-Phase PWM Step-Down Controller with POR

19-2696; Rev 0; 1/03
EVAALVUAAILTAIOBNLEKIT
1.5MHz Dual 180° Out-of-Phase
PWM Step-Down Controller with POR
General Description
The MAX8529 dual, synchronized, step-down controller
generates two outputs from input supplies ranging from
4.75V to 23V. Each output is adjustable from sub-1V
to 18V. Input voltage ripple and total RMS input ripple
current are reduced by synchronized 180-degree out-of-
phase operation.
The switching frequency is adjustable from 600kHz to
1.5MHz with an external resistor. Alternatively, the con-
troller can be synchronized to an external clock gener-
ated to another MAX8529 or a system clock. One
MAX8529 can be set to generate an in-phase, or 90-
degree out-of-phase, clock signal for synchronization
with additional controllers. This allows two controllers to
operate either as an interleaved two- or four-phase sys-
tem with each output shifted by 90 degrees. These
devices also feature soft-start and soft-stop.
The MAX8529 eliminates the need for current-sense
resistors by utilizing the low-side MOSFET’s on-resis-
tance as a current-sense element. This protects the
DC-to-DC components from damage during output
overload conditions or when output short circuit faults
without requiring a current-sense resistor. Adjustable
foldback current limit reduces power dissipation during
short-circuit conditions. The MAX8529 includes a
power-on reset output to signal the system when both
outputs reach regulation.
The MAX8529 is available in a 24-pin QSOP package. An
evaluation kit is available to speed designs.
Features
o Low Output Noise in DSL Band
o Ceramic Input/Output Capacitors
o Step-Down or Step-Up/Step-Down Operation
o Four Output, 90-Degree Out-of-Phase Operation
(Using Two MAX8529s)
o Foldback Current Limit
o 4.75V to 23V Input Supply Range
o 0 to 18V Output Voltage Range (Up to 6A)
o >90% Efficiency
o Fixed-Frequency PWM Operation
o Adjustable 600kHz to 1.5MHz Switching
Frequency
o External SYNC Input
o Clock Output for Master/Slave Synchronization
o Soft-Start and Soft-Stop
o RST Output with 140ms Minimum Delay
o Lossless Current Limit (No Sense Resistor)
Ordering Information
PART
MAX8529EEG
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
24 QSOP
Applications
xDSL Modems and Routers
DSP, ASIC, and FPGA Power Supplies
Set-Top Boxes
Broadband Routers
Pin Configuration
TOP VIEW
COMP2 1
FB2 2
ILIM2 3
OSC 4
V+ 5
REF 6
GND 7
CKO 8
SYNC 9
ILIM1 10
FB1 11
COMP1 12
MAX8529
QSOP
24 EN
23 DH2
22 LX2
21 BST2
20 DL2
19 V_L
18 PGND
17 DL1
16 BST1
15 LX1
14 DH1
13 RST
________________________________________________________________ Maxim Integrated Products 1
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