MAX6652 Datasheet, PDF (1/12 Pages) Maxim Integrated Products – Temperature Sensor and System Monitor in a 10-Pin UMAX

19-1959; Rev 1; 8/01
Temperature Sensor and System Monitor
in a 10-Pin µMAX
General Description
The MAX6652 system supervisor monitors multiple
power-supply voltages, including its own, and also fea-
tures an on-board temperature sensor. Voltages and
temperature are converted to an 8-bit code using an
analog-to-digital converter (ADC). A multiplexer automat-
ically sequences through the voltage and temperature
measurements. The digitized signals are then stored in
registers and compared to the over/under threshold lim-
its programmed over the 2-wire serial interface.
When a temperature measurement exceeds the pro-
grammed threshold, or when an input voltage falls out-
side the programmed voltage limits, the MAX6652
generates a latched interrupt output ALERT. Three inter-
rupt modes are available for temperature excursions:
default mode, one-time interrupt mode, and comparator
mode. The ALERT output is cleared, except for tempera-
ture interrupts generated in comparator mode, by read-
ing the interrupt status register (Table 5). The ALERT
output can also be masked by writing to the appropriate
bits in the interrupt mask register (Table 6) or by setting
bit 1 of the configuration register (Table 4) to 0. The
MAX6652 I²C^™-compatible/SMBus interface also
responds to the SMB alert response address.
The 2-wire serial interface accepts both I²C and standard
system management bus (SMBus) write byte, read byte,
send byte, and receive byte commands to program the
alarm thresholds and to read voltage and temperature
data. Voltage data is scaled so that when the nominal
voltage is present at a pin (e.g., 3.3V for the 3.3V_IN pin),
the conversion result is equal to 3/4 of the ADC full-scale
range or a decimal count of 192 (Table 3). The tempera-
ture data format is 7 bits plus sign, with each data bit
representing 1°C, in two's complement format (Table 2).
The MAX6652 has only one address pin, ADD. One of
four different address codes can be selected by con-
necting the ADD pin to GND, V_CC, SDA, or SCL.
Whenever an I²C-compatible/SMBus transaction is initiat-
ed, the two LSBs of the slave address register are deter-
mined by connection, setting the chip address to one of
four possible values. In addition, an address code can
also be directly written to the serial address register. This
code will overwrite the code set by connection of the
ADD pin, until the MAX6652 is taken through a power-on
reset cycle.
The MAX6652 features 60Hz or 50Hz line-frequency
rejection for optimal performance. The device operates
from +2.7V to +5.5V and is specified for operation from
-40°C to +125°C. It is available in a tiny 10-pin µMAX
package.
I ²C is a trademark of Philips Corp.
Features
o Monitors Four Voltages (2.5V, 3.3V, 12V, V_CC)
o Monitors Local Temperature
o Temperature Measurement Accuracy,
±2°C (T_A = +25°C)
o User-Programmable Voltage and Temperature
Thresholds
o Alert Function with Ability to Respond to SMB
Alert Response Address
o +2.7V to +5.5V Supply Range
o -40°C to +125°C Temperature Range
o 60Hz or 50Hz Line-Frequency Rejection
o Tiny 10-Pin µMAX Package
Workstations
Servers
Applications
Networking
Telecommunications
PART
MAX6652AUB
Ordering Information
TEMP. RANGE
-40°C to +125°C
PIN-PACKAGE
10 µMAX
Pin Configuration
TOP VIEW
12V_IN 1
2.5V_IN 2
3.3V_IN 3
N.C. 4
GND 5
MAX6652
µMAX
10 V_CC
9 SCL
8 SDA
7 ADD
6 ALERT
Typical Application Circuit and Functional Diagram appear
at end of data sheet.
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