MAX1937 Datasheet, PDF (1/24 Pages) Maxim Integrated Products – Two-Phase Desktop CPU Core Supply Controllers with Controlled VID Change

19-2498; Rev 1; 10/02
Two-Phase Desktop CPU Core Supply Controllers
with Controlled VID Change
General Description
The MAX1937/MAX1938/MAX1939 comprise a family of
synchronous, two-phase, step-down controllers capable
of delivering load currents up to 60A. The controllers uti-
lize Quick-PWM™ control architecture in conjunction with
active load-current voltage positioning. Quick-PWM con-
trol provides instantaneous load-step response, while
programmable voltage positioning allows the converter
to utilize full transient regulation limits, reducing the out-
put capacitance requirement. The two phases operate
180° out-of-phase with an effective 500kHz switching fre-
quency, thus reducing input and output current ripple, as
well as reducing input filter capacitor requirements.
The MAX1937/MAX1938/MAX1939 are compliant with
AMD Hammer, Intel^‚ Voltage-Regulator Module (VRM)
9.0/9.1, and AMD Athlon™ Mobile VID code specifica-
tions (see Table 1 for VID codes). The internal DAC pro-
vides ultra-high accuracy of ±0.75%. A controlled VID
voltage transition is implemented to minimize both
undervoltage and overvoltage overshoot during VID
input change.
Remote sensing is available for high output-voltage
accuracy. The MOSFET switches are driven by a 6V
gate-drive circuit to minimize switching and crossover
conduction losses to achieve efficiency as high as
90%. The MAX1937/MAX1938/MAX1939 feature cycle-
by-cycle current limit to ensure that the current limit is
not exceeded. Crowbar protection is available to pro-
tect against output overvoltage.
Applications
Notebook and Desktop Computers
Servers and Workstations
Blade Servers
High-End Switches
High-End Routers
Macro Base Stations
Typical Application Circuits and Functional Diagram appear
at end of data sheet.
Quick-PWM is a trademark of Maxim Integrated Products, Inc.
Athlon is a trademark of Advanced Micro Devices, Inc.
Intel is a registered trademark of Intel Corp.
Features
o ±0.75% Output Voltage Accuracy
o Instant Load-Transient Response
o Up to 90% Efficiency Eliminates Heatsinks
o Up to 60A Output Current
o 8V to 24V Input Range
o User-Programmable Voltage Positioning
o Controlled VID Voltage Transition
o 500kHz Effective Switching Frequency
o MAX1937: AMD Hammer Compatible
o MAX1938: Intel VRM 9.0/9.1 Compatible
o MAX1939: AMD Athlon Mobile Compatible
o Soft-Start
o Power-Good (PWRGD) Output
o Cycle-by-Cycle Current Limit
o Output Overvoltage Protection (OVP)
o R_DS(ON) or R_SENSE Current Sensing
o Remote Voltage Sensing
o 28-Pin QSOP Package
Ordering Information
PART
MAX1937EEI
MAX1938EEI
MAX1939EEI
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
28 QSOP
28 QSOP
28 QSOP
Pin Configuration
TOP VIEW
VID0 1
VID1 2
TIME 3
VID2 4
VID3 5
VID4 6
VPOS 7
VDD 8
ILIM 9
GND 10
GNDS 11
REF 12
EN 13
FB 14
MAX1937
MAX1938
MAX1939
QSOP
28 VCC
27 BST1
26 DH1
25 LX1
24 CS1
23 DL1
22 VLG
21 PGND
20 DL2
19 CS2
18 LX2
17 DH2
16 BST2
15 PWRGD
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.