LOW COST SINGLE TRIP POINT TEMPERATURE SENSOR

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1 LOW COST SINGLE TRIP POINT TEMPERATURE SENSOR FEATURES Temperature Set Point Easily Programs with a Single External Resistor Operates with.v Power Supply () TO-0 Package for Direct Mounting to Heatsink (xat) or Standard -Pin PDIP and SOIC Cost Effective APPLICATIONS Power Supply Over-Temperature Detection Consumer Electronics Fire/ Heat Detection UPSs, Amplifiers, Motors CPU Thermal Management in PCs driven to their active state when the measured temperature exceeds the programmed setpoint. The has a power supply voltage range of.v to.0v while the operates over a power supply range of.v to.v. Both devices are usable over a temperature range of 0 C to + C (Vxx, Vxx). Both devices feature low supply current making them suitable for many portable applications. Eight-pin through-hole and surface mount packages are available. The is also offered in a -pin TO-0 package. TYPICAL APPLICATION +9V 9V BATTERY SENSOR SOUNDER GENERAL DESCRIPTION The and are programmable solid state temperature sensors designed to replace mechanical switches in sensing and control applications. Both devices integrate the temperature sensor with a voltage reference and all required detector circuitry. The desired temperature set point is set by the user with a single external resistor. Ambient temperature is sensed and compared to the programmed setpoint. The and outputs are CONTROL ASIC ALARM Heat Monitor for Smoke Detector ORDERING INFORMATION Part No. Voltage Operation Package Ambient Temperature COA.V to V -Pin SOIC 0 C to +0 C CPA.V to V -Pin Plastic DIP 0 C to +0 C EAT.V to V -Pin TO-0 0 C to + C EOA.V to V -Pin SOIC 0 C to + C EPA.V to V -Pin Plastic DIP 0 C to + C VAT.V to V -Pin TO-0 0 C to + C VOA.V to V -Pin SOIC 0 C to + C VPA.V to V -Pin Plastic DIP 0 C to + C COA.V to.v -Pin SOIC 0 C to +0 C CPA.V to.v -Pin Plastic DIP 0 C to +0 C EOA.V to.v -Pin SOIC 0 C to + C EPA.V to.v -Pin Plastic DIP 0 C to + C VOA.V to.v -Pin SOIC 0 C to + C VPA.V to.v -Pin Plastic DIP 0 C to + C /- //9 TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.

2 ABSOLUTE MAXIMUM RATINGS* Supply Voltage ()...0V ()...V Input Voltage Any Input... ( 0.V) to ( +0.V) Operating Temperature... 0 C to + C C Version... 0 C to +0 C E Version... 0 C to + C V Version... 0 C to + C Maximum Junction Temperature C Storage Temperature... C to +0 C Lead Temperature (Soldering, 0 sec) C *Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (Over Operating Temperature Range, unless otherwise specified.) Parameter Conditions Min Typ Max Unit Supply Voltage Range. V.. Supply Current.0V V µa.v.v 0 00 V OH.0V V, 0 C T A + C, I OH = 0µA 0.90 x V I OH = 00µA 0.0 x V OL 0 C T A + C, I OL = 00µA 0. x V I OL = ma 0.0 x 0 C T A + C, I OL = ma 0. x V OH.V.V, 0 C T A + C, I OH = 0µA 0.9 x V I OH = 00µA 0. x V OL 0 C T A + C, I OL = 00µA 0. x V I OL = ma 0. x 0 C T A + C, I OL = ma 0. x Absolute Accuracy = Programmed Temperature T T ± T + C = Programmed Temperature T T ± T + Trip Point Hysteresis C DETAILED DESCRIPTION Trip Point Programming The and are single point temperature detectors ideal for use in a wide variety of applications. When the temperature of the device exceeds the programmed temperature trip point,, the and outputs are driven into their active states. The desired trippoint temperature is programmed with a single external resistor connected between the input and V CC. The relationship between the resistor value and the trip point temperature is given by the equation below. R TRIP = 0.99 x T. Where Rtrip = Programming resistor value in Ohms T = Desired trip temperature in degrees Kelvin. For example, to program the device to trip at 0 C, the programming resistor is: R TRIP = 0.99 x ((0 +.). ) =, Ω RESISTAE (kω) TEMPERATURE ( C) Figure. Programming Resistor Values vs. Temperature /- //9

3 Hysteresis To prevent output chattering at the trip point temperature, the temperature detector in the / has C of hysteresis (See Figure ). The outputs are driven active when the temperature crosses the setpoint determined by the external resistor. As temperature declines below the setpoint, the hysteresis action will hold the outputs true until the temperature drops C below the threshold. SET POINT (SET POINT - DEGREE C) TEMPERATURE APPLICATIONS Over-Temperature Shutdown The can be used to create a simple overtemperature shutdown circuit. In this circuit, temperature is sensed within the system enclosure (internal system ambient), or at the heatsink itself. When measured temperature exceeds a preset limit, a fault is indicated and the system shuts down. Figure illustrates a simple over-temperature shutdown circuit using the sensor in a single TO-0 package, allowing direct attachment to the heatsink surface. As shown, the outputs are driven active when the heatsink temperature equals the trip point temperature set by. When this happens, the crowbar circuit is activated, causing the supply output to fold back to zero. The outputs remain active until the heatsink temperature falls a minimum of C (built-in hysteresis) below the trip point temperature, at which time the device again allows normal supply operation. Figure. / Hysteresis HEATSINK PUT DEVICE V CC PUT DEVICE V CIRCUIT BOARD Heatsink Mounting POWER GOOD SIGNAL CROWBAR CIRCUIT OVERTEMP HEATSINK SURFACE Figure. Power Supply Over-Temperature Shutdown /- //9

4 Cooling and Heating Applications The / can be used to control a DC fan as shown in Figure. The fan turns on when the sensed temperature rises above and remains on until the temperature falls below C. +. to.0v +V Figure shows the acting as a heater thermostat. Circuit operation is identical to that of the cooling fan application. HEATER +. to.v +V N-CHANNEL LOGIC LEVEL MOSFET + DC FAN N-CHANNEL LOGIC LEVEL MOSFET TEMPERATURE C TEMPERATURE C HEATER "ON" Figure. as a Heater Thermostat FAN "ON" Figure. as a Fan Controller for Notebook PCs /- //9

5 PIN CONFIGURATIONS -Pin DIP -Pin SOIC -Pin TO-0 CPA EPA VPA COA EOA VOA EAT VAT -Pin DIP -Pin SOIC CPA EPA VPA COA EOA VOA NOTE: For TO-0 Package, Pin is connected to case heatsink. /- //9

6 PACKAGE DIMENSIONS -Pin TO-0. (.0). (.9). (.).0 (.). (.).0 (.).0 (0.).90 (9.9). (.9). (.) DIA..0 (.0).0 (.).9 (.09).9 (.) -. PLCS..0 (.). (.).0 (0.9).0 (0.9).00 (0.).0 (0.0). (.9). (.).0 (.).0 (.). (.9).09 (.) -Pin Plastic DIP PIN.0 (.0).0 (.0).0 (.).00 (0.).00 (0.). (.).00 (.).0 (.).0 (.).90 (.).00 (.0).0 (.).0 (.). (.9).00 (.0).00 (0.).0 (0.).00 (0.0) MIN..0 (.9).090 (.9).0 (0.).0 (0.).00 (0.).0 (.) Dimensions: inches (mm) /- //9

7 PACKAGE DIMENSIONS (CONT.) -Pin SOIC PIN indicated by dot and / or beveled edge. (.99).0 (.). (.0). (.9).00 (.) TYP..9 (.00).9 (.0).0 (0.).0 (0.).00 (0.).00 (0.0).09 (.).0 (.) MAX..00 (0.).00 (0.).00 (.).0 (0.0) Dimensions: inches (mm) Sales Offices TelCom Semiconductor, Inc. 00 Terra Bella Avenue P.O. Box Mountain View, CA 909- TEL: FAX: liter@telcom-semi.com /- //9 TelCom Semiconductor, Inc. Austin Product Center 0 MoPac Expressway North Suite A-0 Austin, TX 9 TEL: --00 FAX: --0 TelCom Semiconductor H.K. Ltd. 0 Sam Chuk Street, Ground Floor San Po Kong, Kowloon Hong Kong TEL: --0 FAX: --99

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