LTC1392
Micropower Temperature,
Power Supply and
Differential Voltage Monitor
FEATURES
s
s
s
DESCRIPTIO
s
s
s
s
s
s
Complete Ambient Temperature Sensor Onboard
System Power Supply Monitor
10-Bit Resolution Rail-to-Rail Common-Mode
Differential Voltage Input
Available in 8-Pin SO and PDIP
0.2碌A Supply Current When Idle
700碌A Supply Current When Sampling at
Maximum Rate
Single Supply Voltage: 4.5V to 6V
3-Wire Half-Duplex Serial I/O
Communicates with Most MPU Serial Ports and All
MPU Parallel I/O Ports
The LTC
廬
1392 is a micropower data acquisition system
designed to measure temperature, on-chip supply voltage
and a differential voltage. The differential inputs feature
rail-to-rail common mode input voltage range. The LTC1392
contains a temperature sensor, a 10-bit A/D converter with
sample-and-hold, a high accuracy bandgap reference and
a 3-wire half-duplex serial interface.
The LTC1392 can be programmed to measure ambient
temperature, power supply voltage and an external volt-
age at the differential input pins, that can also be used for
current measurement using an external sense resistor.
When measuring temperature, the output code of the A/D
converter is linearly proportional to the temperature in
擄C.
Production trimming achieves
鹵2擄C
initial accuracy at
room temperature and
鹵4擄C
over the full 鈥?40擄C to 85擄C
temperature range.
The on-chip serial port allows efficient data transfer to a
wide range of MPUs over three or four wires. This,
coupled with low power consumption, makes remote
location sensing possible and facilitates transmitting
data through isolation barriers.
APPLICATI
s
s
s
s
s
S
Temperature Measurement
Power Supply Measurement
Current Measurement
Remote Data Acquisition
Environment Monitoring
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATI
Complete Temperature, Supply Voltage and
Supply Current Monitor
1碌F
TEMPERATURE ERROR (擄C)
Output Temperature Error
5
4
LTC1392C
GUARANTEED
LIMIT
LTC1392I
GUARANTEED
LIMIT
TYPICAL
+
LTC1392
P1.4
MPU
(e.g., 68HC11)
P1.3
P1.2
1
2
3
4
D
IN
D
OUT
CLK
CS
V
CC
鈥揤
IN
+V
IN
GND
8
7
6
5
5V
3
2
1
0
鈥?
鈥?
鈥?
鈥?
鈥?
鈥?0 鈥?0
40
20
0
60
TEMPERATURE (擄C)
80
100
R
SENSE
I
LOAD
LTC1392 鈥?TA01
U
LTC1392 鈥?TA02
UO
UO
1