MIC184 Micrel Semiconductor, MIC184 Datasheet - Page 6

• Manufacturer Part Number: MIC184
• Description: Local/Remote Thermal Supervisor Advance Information
• Manufacturer: Micrel Semiconductor

MIC184
Functional Diagram
Functional Description
Pin Descriptions
VDD
Power supply input. See electrical specifications.
GND
Ground return for all MIC184 functions.
CLK
Clock input to the MIC184 from the two-wire serial bus. The
clock signal is provided by the bus host and is shared by all
devices on the bus.
DATA
Serial data I/O pin that connects to the two-wire serial bus.
DATA is bidirectional and has an open-drain output driver. An
external pull-up resistor or current source somewhere in the
system is necessary on this line. This line is shared by all
devices on the bus.
A2/T1, A1, A0
These inputs set the three least significant bits of the MIC184’s
7-bit slave address. Each MIC184 will only respond to its own
unique slave address, allowing the use of up to eight MIC184s
on a single bus. A match between the MIC184’s address and
MIC184
A2/T1
DATA
CLK
A1
A0
MIC184
Reference
Serial Bus
Bandgap
Interface
Sensor
2-Wire
MUX
and
2:1
Register
Pointer
1-Bit
DAC
Configuration
Temperature
Temperature
Hysteresis
Register
Register
Register
Register
Setpoint
Result
6
the address specified in the serial bit stream must be made
to initiate communication. A1 and A0 should be connected
directly to V
bit input, it should also be tied to V
alternatively connect to a remote temperature sensor. When
A2/T1 is used for temperature measurements, an off-chip
diode junction must be connected between A2/T1 and ground.
In this case, internal circuitry will detect A2 as logic low,
leaving four possible slave addresses. See “Temperature
Measurement” and “Power On” for more information. A2/T1,
A1, and A0 determine the slave address as shown in Table 1.
INT
Temperature events are indicated to external circuitry via this
output. INT may be configured as active-low or active-high by
the host. Operation of the INT output is controlled by the
MODE and POL bits in the MIC184’s configuration register.
See “Comparator and Interrupt Modes” below. This output is
open-drain and may be wire-ORed with other open-drain
signals. Most systems will require a pull-up resistor or current
source on this pin. If the IM bit in the configuration register is
set, it prevents the INT output from sinking current. In I
SMBus systems, the IM bit is therefore an interrupt mask bit.
DD
TEMPERATURE-TO-DIGITAL
Thermostat
Output
or ground. When A2/T1 is used as an address
Digital Filter
Comparator
Machine
Control
Digital
Logic
State
and
and
CONVERTER
INT
DD
or ground. A2/T1 can
November 2000
2
Micrel
C and