MIC184BMM Micrel Inc, MIC184BMM Datasheet - Page 12

• Manufacturer Part Number: MIC184BMM
• Description: IC SUPERVISOR LOCAL/REMOTE 8MSOP
• Manufacturer: Micrel Inc

Specifications of MIC184BMM

• Function: Temp Monitoring System (Sensor)
• Topology: ADC (Sigma Delta), Register Bank
• Sensor Type: External & Internal
• Sensing Temperature: -55°C ~ 125°C, External Sensor
• Output Type: I²C™/SMBus™
• Output Alarm: Yes
• Output Fan: No
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -55°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

MIC184
Interrupt Polarity Selection
The INT output can be programmed to behave as an active-
low signal or an active-high signal. The default is active-low.
INT polarity is selected by programming the appropriate value
into the polarity bit (POL) in the CONFIG register. Clearing
POL selects active-low interrupts; setting POL selects ac-
tive-high interrupts. INT is an open-drain digital output and
may be wire-ORed with other open-drain logic signals. Most
applications will require a pull-up resistor on this pin.
Whether the CONFIG register’s POL bit is set to provide a
current-sinking (low) or high-Z (high) state at the INT pin when
STS is high, writing a one to IM will put the INT pin into a high-
Z state. This meets the requirement of an active-low interrupt
for the SMBus, while making IM available as an INT-forcing
bit for those applications which employ an active-high INT
output (for example, software fan-control routines).
LM75 Compatibility
The MIC184 can be used interchangeably with the LM75 in
existing applications. The MIC184 offers several advantages
MIC184
12
over the LM75:
The three MSB’s of the configuration register (which power
up as zeroes) are used to access the MIC184’s additional
functions. These are reserved bits according to the LM75
specification and, for the LM75, must always be written as
zeroes. The MSB of the MIC184’s status register is a status
flag that does not exist in the LM75. This bit will be set to one
whenever an overtemperature event occurs. This bit would
never be set by an LM75. Software should not depend on this
bit being zero when using the MIC184 as an LM75 upgrade. If
at power-up the measured temperature is higher than T_SET,
the status bit will be set following the first conversion by the
A/D. See “Applications Information” for a method by which
host software can use this fact to differentiate between an
MIC184 and an LM75.
• Ability to monitor a second, remote temperature
• Interrupt masking capability
• Status bit for software polling routines
• Lower quiescent current
• Supports single-byte reads from 16-bit registers
• No “inadvertent 8-bit read” bus lock-up issues
May 2006
Micrel