MIKROE-3683 MikroElektronika

LM75A Digital temperature sensor and thermal watchdog Rev. 04 10 July 2007 Product data sheet 1. General description The LM75A is a temperature-to-digital converter using an on-chip band gap temperature sensor and Sigma-delta A-to-D conversion technique. The device is also a thermal detector providing an overtemperature detection output. The LM75A contains a number of data registers: Conguration register (Conf) to store the device settings such as device operation mode, OS operation mode, OS polarity and OS fault queue as described in Section 7 Functional description temperature register (Temp) to store the digital temp reading, and set-point registers (Tos and Thyst) to store programmable overtemperature shutdown and hysteresis limits, that can be communicated by a controller via the 2-wire 2 serial I C-bus interface. The device also includes an open-drain output (OS) which becomes active when the temperature exceeds the programmed limits. There are three selectable logic address pins so that eight devices can be connected on the same bus without address conict. The LM75A can be congured for different operation conditions. It can be set in normal mode to periodically monitor the ambient temperature, or in shutdown mode to minimize power consumption. The OS output operates in either of two selectable modes: OS comparator mode or OS interrupt mode. Its active state can be selected as either HIGH or LOW. The fault queue that denes the number of consecutive faults in order to activate the OS output is programmable as well as the set-point limits. The temperature register always stores an 11-bit 2 s complement data giving a temperature resolution of 0.125 C. This high temperature resolution is particularly useful in applications of measuring precisely the thermal drift or runaway. The device is powered-up in normal operation mode with the OS in comparator mode, temperature threshold of 80 C and hysteresis of 75 C, so that it can be used as a stand-alone thermostat with those pre-dened temperature set points. 2. Features n Pin-for-pin replacement for industry standard LM75 and offers improved temperature resolution of 0.125 C and specication of a single part over power supply range from 2.8 V to 5.5 V n Small 8-pin package types: SO8 and TSSOP8 2 n I C-bus interface with up to 8 devices on the same bus n Power supply range from 2.8 V to 5.5 V n Temperatures range from - 55 C to +125 C n 11-bit ADC that offers a temperature resolution of 0.125 CLM75A NXP Semiconductors Digital temperature sensor and thermal watchdog n Temperature accuracy of: u 2 C from - 25 C to +100 C u 3 C from - 55 C to +125 C n Programmable temperature threshold and hysteresis set points n Supply current of 3.5 A in shutdown mode for power conservation n Stand-alone operation as thermostat at power-up n ESD protection exceeds 2000 V HBM per JESD22-A114, 200 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101 n Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA 3. Applications n System thermal management n Personal computers n Electronics equipment n Industrial controllers 4. Ordering information Table 1. Ordering information Type number Package Name Description Version LM75AD SO8 plastic small outline package 8 leads SOT96-1 body width 3.9 mm LM75ADP TSSOP8 plastic thin shrink small outline package 8 leads SOT505-1 body width 3 mm 4.1 Ordering options Table 2. Ordering options Type number Topside mark Temperature range LM75AD LM75A T = - 55 C to +125 C amb LM75ADP L75A T = - 55 C to +125 C amb LM75A 4 NXP B.V. 2007. All rights reserved. Product data sheet Rev. 04 10 July 2007 2 of 24