SMM151/152
Single-channel Voltage/Current Monitors and Voltage Marginers
FEATURES & APPLICATIONS
•
Capable of margining supplies with trim inputs using
either positive or negative trim pin control
•
Wide Margin range of 0.3V to VDD with internal
reference
•
Differential Voltage Sensing of the DC-DC converter
output voltage
•
Supply-side current monitoring (10-bit ADC)
2
•
10-bit ADC readout of supply voltage over I C bus
•
Margining Controlled Via:
2
I C Command
Input Pins (M
UP
, M
DN
)
•
Two programmable general purpose sensor inputs
(COMP1/2) – UV/OV with FAULT Output
•
Programmable glitch filters (COMP1/2)
•
Programmable internal COMP1/2 VREF: 0.5V or 1.25V
•
Operates from 2.7V to 5.5V supply
•
Current sensing from 4.0V to 15V supply
•
Programmable, general purpose I/Os (SMM152)
•
General Purpose 256-Byte EEPROM with Write Protect
2
•
I C 2-wire serial bus for programming configuration and
monitoring status
•
28-lead 5x5 QFN
INTRODUCTION
The SMM151/152 are highly accurate power supply
voltage/current supervisors and monitors with provisions for
voltage margining of the monitored supply. The parts include
an internal voltage reference to accurately monitor and margin
the supply to within ±1%. The SMM151/152 have the capability
to margin over a wide range from 0.3V to VDD using the
internal reference and can read the differential voltage of the
supply and voltage drop of the current sense resistor over the
I
2
C bus using an on-chip 10-bit ADC. The margin levels are set
using the I
2
C serial bus. The devices initiate margining via the
2
I C bus or by using the M
UP
or M
DN
inputs. Once the pre-
programmed margin target voltage is reached, the
SMM151/152 hold the converter at this voltage until receiving
an I
2
C command or de-asserting the margin input pin. When
the SMM151/152 are not margining, the TRIM output pin is
held in a high impedance state allowing the converter to
operate at its nominal set point.
Two general purpose input pins are provided for sensing under
or over-voltage conditions. A programmable glitch filter
associated with these inputs allows the user to ignore spurious
noise signals. A FAULT# pin is asserted once either input set
point is exceeded. The SMM152 also provides four
programmable general-purpose inputs/outputs.
Using the I
2
C interface, a host system can communicate with
the SMM151/152 status register and utilize 256-bytes of
nonvolatile memory.
•
•
•
Applications
In-system test and control of Point-of-Load (POL)
Power Supplies for Multi-voltage Processors, DSPs
and ASICs
Routers, Servers, Storage Area Networks
TYPICAL APPLICATION
4.0V-15V
2.7V-5.5V
R
S
CAPC
CS-
CS+
VDD
GND
VDD_CAP
COMP1
V1
Margin
Commands
Status
Outputs
I
2
C
Interface
MUP
MDN
FAULT#
READY
SDA
SCL
A0-A2
WP
(GPIO0)
(GPIO1)
(GPIO2)
(GPIO3)
COMP2
VREF
VIN
SMM151
(SMM152)
VOUT+
SEN+
TRIM
TRIM
CAPM+
VOUT-
SEN-
DC-DC Converter
CAPM-
VM+
VM-
Figure 1 – Application with the SMM151/152 used to Monitor and Margin a DC/DC Converter.
Notes: R
S
must be Kelvin sensed for maximum current sensing accuracy.This is an applications example only. Some components and values are
not shown.
© SUMMIT
Microelectronics, Inc. 2007 • 757 N. Mary Avenue • Sunnyvale CA 94085 • Phone 408 523-1000 • FAX 408 523-1266
http://www.summitmicro.com/
2131 3.0 1/20/2010
1
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
