REGULATOR
BALANCE CONTROLLER
May 27, 1999
EZ1900
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
DESCRIPTION
The EZ1900 is a high performance positive load cur-
rent balancer designed for use in applications utiliz-
ing 2 regulators in parallel to achieve equal current
sharing or identical current for each load. The regula-
tor balance controller allows a flexible motherboard
design to be made to cope with different processor
configurations. The controller reads a logic level up-
grade signal (denoted V
CC2DET
on the Intel P55C; sim-
ilar on AMD, Cyrix and PowerPC microprocessors) to
control the output voltage of two linear low dropout
voltage regulators to the CPU core and I/O planes. In
single-voltage plane configurations (V
CC2DET
floating),
both regulators are set to the same output voltage
(usually 3.3 - 3.5V) and are configured in master-
slave mode. For split plane processors (V
CC2DET
low),
the outputs of the two regulators are switched - the
core voltage will be set to a nominal 2.5V while the
I/O voltage will remain at 3.3V. The actual output
voltages can be adjusted by means of resistors. The
EZ1900 programmable current balancer is available
in the popular SO-8 surface mount package.
FEATURES
•
•
•
•
•
•
Current balance controller for regulators in parallel
Slave and non-slave voltage modes
Slave or non-slave mode computer selected
Compatible with 3 or 5 pin low drop regulators
Remote sense operation
SO-8 package
APPLICATIONS
•
•
•
•
Flexible upgrade from single voltage plane to
split-plane processors
Intel Pentium® Processor P54CS & P55C
upgrades
PowerPC™ 603 & 604 upgrades
AMD5
K
86™ upgrades
ORDERING INFORMATION
DEVICE
EZ1900CS
Note:
(1) Add suffix ‘TR’ for tape and reel.
(1)
PACKAGE
SO-8
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
Parameter
Input Voltage Supply
Differential
Amplifier
Pin #
1
2
3
4
5
6
7
8
Legend
Sel
-IN
+IN
-V
nc
S
OUT
+V
nc
Description
Non-slave mode, voltage select
Negative error amplifier input
Positive error amplifier input
Power input, common
No Connection
Sets V
OUT
of slave device
Power input, positive
No connection
Slave Output Current
(sink only)
Thermal Resistance
Junction to Ambient
Operating Junction
Temperature Range
Storage
Temperature Range
Lead Temperature
(Soldering) 5 Sec
Symbol Maximum
V
IN
-IN, +IN
S
OUT
I
SLAVE
θ
JA
T
J
T
STG
T
LEAD
7
7
0 to +V
50
160
0 to 70
-65 to 125
260
Units
V
V
mA
°C/W
°C
°C
°C
Slave Mode Pin:
For non “Computer Select Operation”, the Select
Mode, pin #1, can be left open circuited for continuous slave mode
operation or balance current control. Ground the Select Mode, pin #1,
for non-slave mode operation.
Pentium Processor is a trademark of Intel Corp. PowerPC is a trademark of IBM Corp. AMD5
K
86 is a trademark of Advanced Micro Devices.
1
© 1999 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320
SEMTECH [ SEMTECH CORPORATION ]
