LTC1392 Datasheet, PDF (1/12 Pages) Linear Technology – Micropower Temperature, Power Supply and Differential Voltage Monitor

LTC1392
Micropower Temperature,
Power Supply and
Differential Voltage Monitor
FEATURES
s _{Complete Ambient Temperature Sensor Onboard}
s _{System Power Supply Monitor}
s _{10-Bit Resolution Rail-to-Rail Common-Mode}
Differential Voltage Input
s _{Available in 8-Pin SO and PDIP}
s _{0.2µA Supply Current When Idle}
s _{700µA Supply Current When Sampling at}
Maximum Rate
s _{Single Supply Voltage: 4.5V to 6V}
s _{3-Wire Half-Duplex Serial I/O}
s _{Communicates with Most MPU Serial Ports and All}
MPU Parallel I/O Ports
APPLICATI S
s _{Temperature Measurement}
s _{Power Supply Measurement}
s _{Current Measurement}
s _{Remote Data Acquisition}
s _{Environment Monitoring}
, LTC and LT are registered trademarks of Linear Technology Corporation.
DESCRIPTIO
The LTC^®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 °C.
Production trimming achieves ±2°C initial accuracy at
room temperature and ±4°C over the full – 40°C to 85°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.
TYPICAL APPLICATI
Complete Temperature, Supply Voltage and
Supply Current Monitor
1µF
+
5V
P1.4
MPU
(e.g., 68HC11)
P1.3
P1.2
LTC1392
1
D_IN
2
D_OUT
3
CLK
4
CS
8
V_CC
7
–V_IN
6
+V_IN
5
GND
R_SENSE
I_LOAD
LTC1392 • TA01
Output Temperature Error
5
4
3
2
1
0
–1
–2
–3
–4
–5
–40 –20
0 20 40 60 80 100
TEMPERATURE (°C)
LTC1392 • TA02
LTC1392C
GUARANTEED
LIMIT
LTC1392I
GUARANTEED
LIMIT
TYPICAL
1