SUMMIT
MICROELECTRONICS, Inc.
SMS45
PRELIMINARY INFORMATION
1
(SEE LAST PAGE)
Quad Programmable Precision Cascade Sequencer and Supervisory
Controller with
4k-Bit Nonvolatile Memory
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
4k-Bit Nonvolatile General Purpose Memory
APPLICATIONS
Desktop/Notebook/Tablet Computers
Multi-voltage Systems
Telecom/Network Servers
Portable Battery-powered Equipment
Set-top Boxes
Data-storage Equipment
INTRODUCTION
The SMS45 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 SMS45 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 SMS45 can also be used to enable DC/DC converters
or LDOs to provide a closed loop cascading of the supplies
during power -up.
The SMS45 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 interface
adapter and Windows GUI software obtainable from Sum-
mit 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
SMS45
PUP#2
1
MR#
15
WLDI
GND
8
RESET#
11
PUP#3
0.1µF
5
DC-DC
2.5V
Reset#
13
LDO
1.8V
Applications Schematic using the SMS45 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., 2004
Characteristics subject to change without notice
• 1717 Fox Dr. • San Jose, CA 95131 • Phone 408-436-9890 • FAX 408-436-9897 •
2079 1.2 05/24/04
www.summitmicro.com
1
SMS45
Preliminary Information
INTERNAL BLOCK DIAGRAM
VDD_CAP
50kΩ
CONFIGURATION
REGISTER
11
RESET#
MR#
1
V0
16
NV DAC +
REF
–
PROGRAMMABLE
RESET PULSE
GENERATOR
V1
2
NV DAC
REF
+
–
PROGRAMMABLE
POWER
CASCADING
4
PUP#1
5
PUP#2
13
PUP#3
V2
3
NV DAC
REF
+
–
PROGRAMMABLE
WATCHDOG
TIMER
SERIAL
BUS
CONTROL
LOGIC
9
SDA
10
SCL
7
A2
6
A1
V3
14
NV DAC
REF
+
–
50kΩ
15
WLDI
SUPPLY
ARBITRATION
CONFIGURATION
REGISTER
4K-BIT NV
MEMORY
VDD_CAP
V0
V1
V2
V3
12
8
VDD_CAP
GND
CASCADE SEQUENCING
Time based sequencing has the ability to turn supplies on
in a specific order. However, it cannot guarantee that each
supply has reached valid voltage levels before the next
supply is sequenced on. Cascade sequencing guarantees
the supplies are enabled a programmed period of time after
the previous voltage has reached its minimum pro-
grammed valid level. Figure 1 shows that each succeeding
voltage must reach its minimum valid level before the timer
is started to time the interval,
t,
for the next voltage. The
duration of each
t
is programmable for each supply to
supply transition. The next supply is not enabled until the
timer has elapsed. See also Figure 5.
6V
5V
5V Valid
4V
V
3.3V Valid
3.3V
2.5V
2V
2.5V Valid
1.8V
0V
t
t
t
T
2047 Fig01
Figure 1. Cascading Power Supplies
2
2079 1.2 05/24/04
SUMMIT MICROELECTRONICS, Inc.
SMS45
Preliminary Information
PIN CONFIGURATION
PIN NAMES
Pin
1
MR#
V
1
V
2
PUP#1
PUP#2
A1
A2
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
0
WLDI
V
3
PUP#3
VDD_CAP
RESET#
SCL
SDA
2047 PCon 2.0
Name
MR#
V
1
V
2
PUP#1
PUP#2
A1
A2
GND
SD A
SC L
RESET#
PUP#3
V
3
WLDI
V
0
Function
Manual reset input
Voltage supply and monitor input
Voltage supply and monitor input
Power up permitted output
Power up permitted output
Address input
Address input
Power supply return
Serial data I/O
Serial data clock
Reset out
Power up permitted
Voltage supply and monitor input
Watchdog Timer interrupt
Voltage supply and monitor input
2047 Pins Table 2.0
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
VDD_CAP Power supply output
SUMMIT MICROELECTRONICS, Inc.
2079 1.2 05/24/04
3
SMS45
Preliminary Information
ABSOLUTE MAXIMUM RATINGS*
Temperature Under Bias ...................... –55°C to 125°C
Storage Temperature ............................. –65°C to 150°C
Lead Solder Temperature (10s) ........................... 300 °C
Terminal Voltage with Respect to GND:
V
0
, V
1
, V
2
, and V
3
......... –0.3V to 6.0V
All Others ....................... –0.3V to 6.0V
Junction Temperature.......................…….....…...150°C
ESD Rating per JEDEC……………………..….…..2000V
Latch-Up testing per JEDEC………..…….......…±100mA
*Note
-
Stresses beyond the listed Absolute Maximum Ratings may
cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions
outside those listed in the operational sections of this specification is not
implied. Exposure to any absolute maximum rating for extended
periods may affect device performance and reliability.
RECOMMENDED OPERATING CONDITIONS
Industrial Temperature Range............... –40ºC to +85ºC.
Commercial Temperature Range..............–5ºC to +70ºC.
V
SUPPLY
Supply Voltage............................2.7V to 5.5V
V
SUPPLY
=
Device supply voltage provided by the
highest V
X
input.
Package Thermal Resistance (θJA)
16 Lead SSOP…………………….………….…23
o
C/W
Moisture Classification Level 1 (MSL 1) per J-STD- 020
RELIABILITY CHARACTERISTICS
Data Retention………………….…………..…..100 Years
Endurance……………………….…..…….100,000 Cycles
DC OPERATING CHARACTERISTICS
(Over
Recommended Operating Conditions; Voltages are relative to GND)
Symbol
Parameter
Notes
1V Min. refers to a valid reset out-
put being generated
Min.
1.0
Typ.
Max.
5.5
Unit
V
V
SUPPLY
Operating supply voltage
Memory read/write operations: at
least one of the V
X
inputs must be
at or above V
SUPPLY
min.
VDD_CAP = 5.5V; V
0
trip point 4.7V; V
1
, V
2
,
V
3
= GND; MR# = V
CC
; all outputs
floating
2.7
5.5
V
200
400
3
µA
mA
V
V
%
mV
I
CC
Supply current
V
PTH
Programmable threshold
Range range (low range)
V
PTH
Programmable threshold
Range range (high range)
V
PTHACC
V
HYST
V
OL
V
IL
V
IH
Programmable threshold
Accuracy
V
RST
hysteresis
Low voltage output
Configuration register or memory
access
Reset threshold voltage range V
0
to V
3
(5mV increments)
Reset threshold voltage range V
0
to V
3
(15mV increments)
V
PTH
is the programmed threshold
setpoint within the V
PTH
Range
See Note 1 below
I
SINK
= 1mA, V
VDD_CAP
≥
2.7V
I
SINK
= 200µA, V
VDD_CAP
= 1.0V
0.6
1.8
–1.0
V
PTH
30
1.875
5.625
1.0
0.3
0.3
0.6
0.7
×
V
CC
V
V
V
V
Input threshold
Note 1: Low Range Hysteresis = 4.2 X (Vtrip - 0.5 volts) mV. For Vtrip = 1.0 volts, Hysteresis = 2.1 mV (0.21 %),
High Range Hysteresis = 12.6 X (Vtrip -0.5 volts) mV. For Vtrip = 5.0 volts, Hysteresis = 56.7 mV (1.13%).
4
2079 1.2 05/24/04
SUMMIT MICROELECTRONICS, Inc.
SMS45
Preliminary Information
AC OPERATING CHARACTERISTICS
(Over
Recommended Operating Conditions; Voltages are relative to GND, also see configuration registers)
Symbol
Parameter
WD2
0
0
Programmable Watchdog
timer period
Notes
WD1
0
1
0
0
1
1
PUP#X-1
0
WD0
X
1
0
1
0
1
PUP#X-0
0
1
0
1
Min.
Typ.
Max.
Unit
OFF
300
600
1200
2400
4800
400
800
1600
3200
6400
500
1000
2000
4000
8000
—
t
PWDTO
1
1
1
1
ms
0ms
19
38
75
25
50
100
100
31
63
125
—
t
PDLY
X
Programmable delay from
V
PTH
to PUP# out
0
1
1
ms
I
MR
T
MR
T
DMRRST
MR# pullup current
MR# input pulse width
Delay from MR# low to
RESET# low
RTO1
0
Programmable reset pulse
width
RTO0
0
1
0
1
19
38
75
150
Minimum
µA
ns
ns
300
200
25
50
100
200
20
31
63
125
250
ms
ms
ms
ms
µs
t
PRTO
0
1
1
t
DRST
V in to RESET# delay
100mV overdrive
SUMMIT MICROELECTRONICS, Inc.
2079 1.2 05/24/04
5
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