MIC384
Micrel
Functional Diagram
VDD
8-Bit Sigma-Delta ADC
T1
T2
3:1
MUX
∑
∫
Digital Filter
and
Control
Logic
Bandgap
Sensor
and
Reference
1-Bit
DAC
Result
Registers
A0
2-Wire
Serial Bus
Interface
DATA
CLK
Pointer
Register
Temperature
Setpoint
Registers
Temperature
Hysteresis
Registers
State
Machine
and
Digital
Comparator
Configuration
Register
Open-Drain
Output
MIC384
GND
/INT
Functional Description
Pin Descriptions
VDD:
Power supply input. See electrical specifications.
GND:
Ground return for all MIC384 functions.
CLK:
Clock input to the MIC384 from the two-wire serial bus.
The clock signal is provided by the 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 bi-directional and has an open-drain output
driver. An external pull-up resistor or current source some-
where in the system is necessary on this line. This line is
shared by all devices on the bus.
A0:
This inputs sets the least significant bit of the MIC384’s
7-bit slave address. The six most-significant bits are fixed
and are determined by the part number ordered. (See order-
ing information table above.) Each MIC384 will only respond
to its own unique slave address, allowing up to eight MIC384’s
to share a single bus. A match between the MIC384’s
address and the address specified in the serial bit stream
must be made to initiate communication. A0 should be tied
directly to VDD or ground. See "Temperature Measurement
and Power On" for more information. A0 determines the slave
address as shown in Table 1:
Part Number
MIC384-0
MIC384-1
MIC384-2
MIC384-3
Inputs
A0
0
1
0
1
0
1
0
1
MIC384 Slave Address
Binary
100 1000
b
100 1001
b
100 1010
b
100 1011
b
100 1100
b
100 1101
b
100 1110
b
100 1111
b
Hex
48
h
49
h
4A
h
4B
h
4C
h
4D
h
4E
h
4F
h
Table 1. MIC384 Slave Address Settings
/INT:
Temperature events are indicated to external circuitry
via this output. Operation of the /INT output is controlled by
the MODE and IM bits in the MIC384’s configuration register.
See "Comparator and Interrupt Modes" below. This output is
open-drain and may be wire-OR’ed 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
6
September 2000
MIC384
MICREL [ MICREL SEMICONDUCTOR ]
