TC74A3-3.3VAT

TC74 Tiny Serial Digital Thermal Sensor Features General Description • Digital Temperature Sensing in SOT-23-5 or TO-220 Packages • Outputs Temperature as an 8-Bit Digital Word • Simple SMBus/I2C™ Serial Port Interface • Solid-State Temperature Sensing: - ±2°C (max.) Accuracy from +25°C to +85°C - ±3°C (max.) Accuracy from 0°C to +125°C • Supply Voltage of 2.7V to 5.5V • Low Power: - 200 µA (typ.) Operating Current - 5 µA (typ.) Standby Mode Current The TC74 is a serially accessible, digital temperature sensor particularly suited for low cost and small formfactor applications. Temperature data is converted from the onboard thermal sensing element and made available as an 8-bit digital word. Applications • Thermal Protection for Hard Disk Drives and other PC Peripherals • PC Card Devices for Notebook Computers • Low Cost Thermostat Controls • Power Supplies • Thermistor Replacement Package Types Communication with the TC74 is accomplished via a 2wire SMBus/I2C compatible serial port. This bus also can be used to implement multi-drop/multi-zone monitoring. The SHDN bit in the CONFIG register can be used to activate the low power Standby mode. Temperature resolution is 1°C. Conversion rate is a nominal 8 samples/sec. During normal operation, the quiescent current is 200 µA (typ). During standby operation, the quiescent current is 5 µA (typ). Small size, low installed cost and ease of use make the TC74 an ideal choice for implementing thermal management in a variety of systems. Functional Block Diagram Internal Sensor (Diode) TO-220 SOT-23 SCLK SDA SCLK 5 4  Modulator TC74 Control Logic TC74 12345 NC SDA GND SCLK VDD SDA Serial Port Interface 1 2 3 NC GND VDD Temperature Register Note: The TO-220 tab is connected to pin 3 (GND)  2001-2012 Microchip Technology Inc. DS21462D-page 1 TC74 1.0 ELECTRICAL CHARACTERISTICS 1.1 Absolute Maximum Ratings† Supply Voltage (VDD) ............................................ +6V Voltage On Any Pin ....... (GND – 0.3V) to (VDD + 0.3V) † Notice: Stresses above those listed under "Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Current On Any Pin ..........................................±50 mA Operating Temperature (TA) ........ -40°C  TA  +125°C Storage Temperature (TSTG) ..............-65°C to +150°C Junction Temperature (TJ)................................ +150°C DC CHARACTERISTICS Electrical Specifications: Unless otherwise noted, VDD = 3.3V for TC74AX-3.3VXX and VDD = 5.0V for TC74AX-5.0VXX, -40°C  TA  125°C. Note 5 Parameters Sym Min Typ Max Units Conditions Power-on Reset Threshold VPOR 1.2 — 2.2 V Supply Voltage VDD 2.7 — 5.5 V Note 5 Operating Current IDD — 200 350 µA VDD = 5.5V, Note 1 IDD-STANDBY — 5.0 10 µA VDD = 3.3V Serial Port Inactive, Note 4 TERR -2.0 -3.0 — — — ±2.0 +2.0 +3.0 — °C +25°C