a
FEATURES
Up to Eight Measurement Channels
Five Inputs to Measure Supply Voltages
V
CC
Monitored Internally
External Temperature Measurement with Remote Diode
On-Chip Temperature Sensor
Five Digital Inputs for VID Bits
Integrated 100 k Pull-Ups on VID Pins (ADM1025 Only)
LDCM Support
I
2
C
®
-Compatible System Management Bus (SMBus)
Programmable
RESET
Output Pin
Programmable
INT
Output Pin
Configurable Offset for Internal/External Channel
Shutdown Mode to Minimize Power Consumption
Limit Comparison of all Monitored Values
APPLICATIONS
Network Servers and Personal Computers
Microprocessor-Based Office Equipment
Test Equipment and Measuring Instruments
Low-Cost PC
Hardware Monitor ASIC
ADM1025/ADM1025A*
PRODUCT DESCRIPTION
The ADM1025/ADM1025A is a complete system hardware
monitor for microprocessor-based systems, providing measure-
ment and limit comparison of various system parameters. Five
voltage measurement inputs are provided, for monitoring 2.5 V,
3.3 V, 5 V and 12 V power supplies and the processor core
voltage. The ADM1025/ADM1025A can monitor a sixth power
supply voltage by measuring its own V
CC
. One input (two pins) is
dedicated to a remote temperature-sensing diode, and an on-chip
temperature sensor allows ambient temperature to be moni-
tored. The ADM1025A has open-drain VID inputs while the
ADM1025 has on-chip 100 kΩ pull-ups on the VID inputs.
Measured values and in/out of limit status can be read out via
an I
2
C-compatible serial System Management Bus. The device
can be controlled and configured over the same serial bus. The
device also has a programmable
INT
output to indicate under-
voltage, overvoltage and over-temperature conditions.
The ADM1025/ADM1025A’s 3.0 V to 5.5 V supply voltage
range, low supply current, and I
2
C-compatible interface make
it ideal for a wide range of applications. These include hardware
monitoring and protection applications in personal computers,
electronic test equipment, and office electronics.
FUNCTIONAL BLOCK DIAGRAM
V
DD
VID0
VID1
VID2
VID3
300k
12V
IN
/VID4
V
CC
POWER TO CHIP
100k
PULLUPS
VID4
REGISTER
SERIAL BUS
INTERFACE
ADD/RST/INT/NTO
SDA
SCL
VID0–3
REGISTER
ADM1025/
ADM1025A
VALUE AND
LIMIT
REGISTERS
V
CCPIN
2.5V
IN
3.3V
IN
5V
IN
D+
D–/NTI
BANDGAP
TEMPERATURE
SENSOR
INPUT
ATTENUATORS
AND
ANALOG
MULTIPLEXER
ADDRESS
POINTER
REGISTER
LIMIT
COMPARATORS
MEASUREMENT
STATUS
REGISTERS
ADC
OFFSET
REGISTER
2.5V
BANDGAP
REFERENCE
CONFIGURATION
REGISTER
GND
*Patent
Pending.
I
2
C is a registered trademark of Philips Corporation.
REV. A
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
AD [ ANALOG DEVICES ]
