
SMS64 
Six-Channel Supply Monitor and Sequencing Controller 
Preliminary
SUMMIT MICROELECTRONICS, Inc. 2003    1717 Fox Dr.     San Jose, CA 95131    Phone 408-436-9890    FAX 408-436-9897    
wwwsummitmicro.com 
Characteristics Subject to Change Without Notice
2060 2.22 10/09/03 
1
FEATURES & APPLICATIONS 
 
Monitors and Controls up to 6 Power  
   Supplies 
 
Programmable Sequencing for both Power- 
   on and Power-off 
 
Programmable Threshold Sensors 
 
Programmable Reset and Interrupt Functions 
 
Programmable Watchdog/Longdog Timer 
 
Fault and Status Registers 
 
4k-Bit Nonvolatile Memory 
Applications 
 
Monitor and Control Distributed Power and 
Point of Use Power Supplies 
 
Telecom 
 
Compact PCI 
 
Servers 
 
Multi-voltage Network Processors, DSPs, 
ASICs 
INTRODUCTION 
The SMS64 is a highly integrated power supply 
monitor and controller.  The SMS64 has six supply 
managers, each individually programmable with 
regard to threshold voltages, actions that can be taken 
with either an under- or over-voltage condition and 
how that manager will operate in sequencing the 
power-on operation. 
The managers can act independently or sequenced 
with any other manager in the device.  When the 
managers work together the device can control the 
sequence in which power is applied to the application 
circuits.  Each manager is assigned to a sequence 
position which allows the device to perform power 
supply sequencing in any order.  For power-off 
situations the SMS64 can sequence the supplies 
either in the same order or reverse order from the 
power-on sequence. 
The SMS64 has two programmable Watchdog 
timers, two programmable reset outputs and a 
programmable IRQ# output.  Using the I
2
C 2-wire 
serial interface, a host system can communicate with 
the SMS64 status register, optionally control power-on 
via software and utilize 4 K-bits of nonvolatile memory.  
GND
V+
OUT
SET
ON/OFF
GND
V+
OUT
ON/OFF
GND
V+
OUT
SET
SHDN
3.3V
2.7V
V
A
P
A
V
A
V
B
P
B
V
B
P
C
V
C
PUP
D
V
D
P
F
V
F
P
E
V
E
ASIC
DSP
2.5V
1.8V
2.0V
1.5V
HAVGGCA
IQ
RST_A#
R
VCC_CAP
GND
Power-On
IRQ#
HEALTHY#
GND
MR#
RESET#
SMS64
GND
V+
OUT
ON/OFF
PWR_ON/OFF
2.7V
2.7V
UP
Power Supply Sequencing and System Start-up Initialization using the SMS64
This is an example application and the specific component values are purposely not shown.  The SMS64 can be used with any combination of
MOSFETs, LDOs or DC/DC converters to optimize sequencing and minimize losses in the power chain. 
SIMPLIFIED APPLICATIONS DRAWING