MAX5951 Datasheet, PDF (1/25 Pages) Maxim Integrated Products – 12V/5V Input Buck PWM Controller

19-0546; Rev 0; 5/06
12V/5V Input Buck PWM Controller
General Description
The MAX5951 is a 12V pulse-width modulated (PWM),
step-down, DC-DC controller. The device operates over
the input-voltage range of 8V to 16V or 5V ±10%, and
provides an adjustable output from 0.8V to 5.5V. The
device delivers up to 10A of load current with excellent
load-and-line regulation.
The MAX5951 PWM section utilizes a voltage-mode
control scheme for good noise immunity and offers
external compensation, allowing for maximum flexibility
with a wide selection of inductor values and capacitor
types. The device operates at a fixed switching fre-
quency that is programmable from 100kHz to 1MHz
and can be synchronized to an external clock signal
though the SYNCIN input. The device includes under-
voltage lockout (UVLO) and digital soft-start. Protection
features include lossless valley-mode current limit, hic-
cup-mode output short-circuit protection, and thermal
shutdown.
The MAX5951 is available in a space-saving 5mm x
5mm, 32-pin thin QFN package and is specified for
operation over the -40°C to +85°C extended tempera-
ture range. Refer to the MAX5950 data sheet for a pin-
compatible PWM controller with hot swap.
Applications
PCI-e Express Modules™
General 12V or 5V Input PWM Controllers
Blade Servers
RAID
Base Stations
Workstations
PCI-e Express Modules is a trademark of PCI-SIG.
Features
♦ 8V to 16V or 5V ±10% Input-Voltage Range
♦ Lossless Valley-Mode Current Sensing
♦ Output Voltage Adjustable from 0.8V to 5.5V
♦ Voltage-Mode Control
♦ External Compensation for Maximum Flexibility
♦ Digital Soft-Start
♦ Sequencing or Ratiometric Tracking
♦ Startup Synchronization
♦ Programmable PGOOD Output
♦ Programmable Switching Frequency from 100kHz
to 1MHz
♦ External Frequency Synchronization
♦ SYNCIN and SYNCOUT Enable 180° Out-of-Phase
Operation
♦ Thermal Shutdown and Short-Circuit Protection
♦ Space-Saving, 5mm x 5mm, 32-Pin TQFN Package
Ordering Information
PART
TEMP RANGE
MAX5951ETJ+ -40°C to +85°C
+Denotes lead-free package.
PIN-
PACKAGE
32 TQFN
PKG
CODE
T3255-4
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
CS- 25
16 SYNCIN
PGND 26
15 SYNCOUT
DL 27
14 AGND
DREG 28
LX 29
MAX5951
13 THRESH
12 DCENI
DH 30
11 N.C.
BST 31
REG 32 ⁺
10 N.C.
9 N.C.
1 2345678
TQFN
(5mm x 5mm)
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1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.