LTC1392 Micropower Temperature, Power Supply and Differential Voltage Monitor DESCRIPTIO FEATURES n Complete Ambient Temperature Sensor Onboard The LTC 1392 is a micropower data acquisition system n System Power Supply Monitor designed to measure temperature, on-chip supply voltage n 10-Bit Resolution Rail-to-Rail Common-Mode and a differential voltage. The differential inputs feature Differential Voltage Input rail-to-rail common mode input voltage range. The LTC1392 n Available in 8-Pin SO and PDIP contains a temperature sensor, a 10-bit A/D converter with n 0.2A Supply Current When Idle sample-and-hold, a high accuracy bandgap reference and n 700A Supply Current When Sampling at a 3-wire half-duplex serial interface. Maximum Rate The LTC1392 can be programmed to measure ambient n Single Supply Voltage: 4.5V to 6V temperature, power supply voltage and an external volt- n 3-Wire Half-Duplex Serial I/O age at the differential input pins, that can also be used for n Communicates with Most MPU Serial Ports and All current measurement using an external sense resistor. MPU Parallel I/O Ports When measuring temperature, the output code of the A/D converter is linearly proportional to the temperature in C. PP IC I A L AT S Production trimming achieves 2C initial accuracy at room temperature and 4C over the full 40C to 85C n Temperature Measurement temperature range. n Power Supply Measurement n Current Measurement The on-chip serial port allows efficient data transfer to a n Remote Data Acquisition wide range of MPUs over three or four wires. This, n Environment Monitoring coupled with low power consumption, makes remote location sensing possible and facilitates transmitting , LTC and LT are registered trademarks of Linear Technology Corporation. data through isolation barriers. TYPICAL APPLICATI Output Temperature Error Complete Temperature, Supply Voltage and Supply Current Monitor 5 LTC1392C GUARANTEED 4 LIMIT 1F 5V 3 + LTC1392I GUARANTEED 2 LIMIT LTC1392 1 TYPICAL 1 8 0 P1.4 D V IN CC R SENSE 2 7 MPU 1 D V OUT IN (e.g., 68HC11) 3 6 2 I P1.3 CLK +V LOAD IN 4 5 3 P1.2 CS GND 4 LTC1392 TA01 5 40 100 40 20 0 20 60 80 TEMPERATURE (C) LTC1392 TA02 1 TEMPERATURE ERROR (C) UO UO ULTC1392 ABSOLUTEXAI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) ORDER PART Supply Voltage (V ) ................................................ 7V CC TOP VIEW NUMBER Input Voltage ................................. 0.3V to V + 0.3V CC Output Voltage ............................... 0.3V to V + 0.3V D 1 8 V IN CC CC LTC1392CN8 D 2 V Operating Temperature Range 7 OUT IN LTC1392CS8 CLK 3 6 +V LTC1392C............................................... 0C to 70C IN LTC1392IN8 CS 4 5 GND LTC1392I........................................... 40C to 85C LTC1392IS8 Junction Temperature.......................................... 125C N8 PACKAGE S8 PACKAGE 8-LEAD PDIP 8-LEAD PLASTIC SO Storage Temperature Range ................ 65C to 150C S8 PART MARKING Lead Temperature (Soldering, 10 sec)................. 300C T = 125C, = 100C/ W (N8) JMAX JA T = 125C, = 130C/ W (S8) JMAX JA 1392 1392I Consult factory for Military grade parts. LECTR AL CHARACTERIST E IC ICS (Note 2, 3) PARAMETER CONDITIONS MIN TYP MAX UNITS Power Supply To Digital Conversion Resolution V = 4.5V to 6V 10 Bit CC Total Absolute Error V = 4.5V to 6V l 8 LSB CC Differential Voltage to Digital Conversion (Full-Scale Input = 1V) Resolution 10 Bit Integral Linearity Error (Note 5) l 0.5 1 LSB Differential Linearity Error l 0.5 1 LSB Offset Error l 4 LSB Full-Scale Error l 15 LSB Differential Voltage to Digital Conversion (Full-Scale Input = 0.5V) Resolution 10 Bit Integral Linearity Error (Note 5) l 0.5 2 LSB Differential Linearity Error l 0.5 1 LSB Offset Error l 8 LSB Full-Scale Error l 25 LSB Temperature to Digital Conversion Accuracy T = 25C (Note 7) 2 C A T = T or T (Note 7) l 4 C A MAX MIN Nonlinearity T T T (Note 4) 1 C MIN A MAX 2 U W W W U WU