SUMMIT
MICROELECTRONICS, Inc.
SMS47
PRELIMINARY INFORMATION
1
(SEE LAST PAGE)
Quad Programmable Precision Cascade Sequencer and Supervisory
Controller
FEATURES
Operational from any of four Voltage Monitoring
Inputs
Programmable Power-up Cascade Sequencing
Programmability allows monitoring any voltage
between 0.6V and 5.6V with no external
components
Programmable 5mV steps in the low range
Programmable Watchdog Timer
Programmable Reset Pulse Width
Programmable Nonvolatile Combinatorial Logic
for generation of Reset
Fault Status Register
APPLICATIONS
Desktop/Notebook/Tablet Computers
Multi-voltage Systems
Telecom/Network Servers
Portable Battery-powered Equipment
Set-top Boxes
Data-storage Equipment
INTRODUCTION
The SMS47 is a nonvolatile user-programmable voltage
supply cascade sequencer and supervisory circuit de-
signed specifically for advanced systems that need to
monitor multiple voltages. The SMS47 can monitor four
separate voltages without the need of any external voltage
divider circuitry unlike other devices that need factory-
trimmed threshold voltages and external components to
accommodate different supply voltages and tolerances.
The SMS47 can also be used to enable DC/DC converters
or LDOs to provide a closed loop cascading of the supplies
during power-up.
The SMS47 watchdog timer has a user programmable
time-out period and it can be placed in an idle mode for
system initialization or system debug. All of the functions
are user accessible through an industry standard I
2
C 2-wire
serial interface.
Programming of configuration, control and calibration
values by the user is simplified with the SMX3200 program-
ming adapter and Windows GUI software obtainable from
Summit Microelectronics.
SIMPLIFIED APPLICATION DRAWING
5V
I
2
C
7
6
9
10
4
DC/DC
3.3V
12 VDD_CAP A2 A1 SDA SCL
PUP#1
16
V0
2
V1
3
V2
14
V3
SMS47
PUP#2
1 MR#
15
WLDI
GND
8
RESET#
11
PUP#3
0.1µF
5
DC/DC
2.5V
Reset#
13
LDO
1.8V
2047 SAD 2.0
Applications Schematic using the SMS47 Controller to provide closed loop power-up cascade sequenc-
ing and supervisory functions.
NOTE: THIS IS AN APPLICATIONS EXAMPLE ONLY. SOME PINS, COMPONENTS AND VALUES ARE NOT SHOWN.
©SUMMIT MICROELECTRONICS, Inc., 2005
Characteristics subject to change without notice
• 1717 Fox Dr. • San Jose, CA 95131 • Phone 408-436-9890 • FAX 408-436-9897 •
2087 1.1 04/11/05
www.summitmicro.com
1
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
