PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1023 TC1024 TC1024 PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE FEATURES GENERAL DESCRIPTION ■ ■ ■ ■ ■ The TC1023/1024 temperature sensors furnish a linearized output voltage directly proportional to measured temperature. The TC1023 has a temperature measurement range of – 20°C to +100°C. Its output voltage is directly calibrated in degrees Centigrade (i.e., VOUT = 10mV/°C x Temperature °C). An external pull-down resistor to a negative voltage source is required for temperature measurement below 0°C. The TC1024 has a temperature measurement range of – 20°C to +125°C, and operates with a single supply. It has the same output voltage slope with temperature as the TC1023 (10mV/°C). The output voltage range is 100mV at – 20°C to 1,750mV at +125°C. Both devices have a chip enable input that reduces supply current to 1µA (typical) when pulled active high. In this state, the output defaults to a high resistance allowing an external reference voltage to be directly connected for A/D calibration. Small size, low cost, flexibility and low power operation make the TC1023/1024 suitable for a wide range of general purpose temperature measurement applications. ■ ■ ■ Linearized Temperature-to-Voltage Converters Direct Centigrade Output Voltage Scaling (TC1023) Shutdown/Calibrate Mode Multi-Zone Temperature Sensing Capability Wide Temperature Measurement Range (TC1024) ........................... – 20°C to +125°C Excellent Temperature Converter Linearity .. 0.8°C Over Temperature High Temperature Converter Accuracy ......... ± 2°C at 25°C Guaranteed Small Packages ......... 8-Pin SOIC and 8-Pin MSOP APPLICATIONS ■ ■ ■ ■ ■ ■ Power Supply Thermal Shut-Down Temperature-Controlled Fans Temperature Measurement/Instrumentation Temperature Regulators Consumer Electronics Lithium Battery Temperature Monitor ORDERING INFORMATION TYPICAL APPLICATION VCC = 2.2V to 12V MICROCONTROLLER VCC VOUT A/D CONVERTER TC1023 GND Part No. Package Output Voltage At 25°C TC1023VOA TC1023VUA TC1024VOA TC1024VUA 8-Pin SOIC 8-Pin MSOP 8-Pin SOIC 8-Pin MSOP 250mV 250mV 750mV 750mV Temp. Range – 20°C to +100°C – 20°C to +100°C – 20°C to +125°C – 20°C to +125°C PIN CONFIGURATION CE 8-Pin SOIC I/O LINE TC1023/1024-05 6/12/97 VOUT 1 NC 2 NC 3 GND 4 TelCom Semiconductor reserves the right to make changes in the circuitry and 1 specifications of its devices. MSOP-8 8 TC1023VOA TC1024VOA VCC 7 NC 6 NC 5 CE VOUT 1 8 VCC NC 2 7 NC NC 3 6 NC GND 4 5 CE TC1023VUA TC1024VUA PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1024 * Static-sensitive device. Unused devices must be stored in conductive material. Protect devices from static discharge and static fields. 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 operational sections of the specifications is not implied. Exposure to Absolute Maximum Rating Conditions for extended periods may affect device reliability. ABSOLUTE MAXIMUM RATINGS * Supply Voltage ............................................................15V Input Voltage, Any Terminal .............. – 1.0 to (VCC +0.3V) Operating Temperature (TC1023) ......... – 20°C to +100°C Operating Temperature (TC1024) ......... – 20°C to +125°C Storage Temperature ............................ – 55°C to +150°C Lead Temperature (Soldering, 10 sec) ................. +300°C ELECTRICAL CHARACTERISTICS : TA = – 20°C to +125°C, VCC = 5V ±5%, GND = 0V, unless otherwise specified. Symbol Parameter VCC IS Supply Voltage (TC1023) (TC1024) Supply Current ICE Shutdown Current VIH VIL ICE tREC CE Input Logic HIGH Level CE Input Logic LOW Level CE Input Leakage Current Recovery Time from Shutdown VOUT VOUT Output Voltage (TC1024) VOUT Output Voltage (TC1023) ISRC VOUT Output Source Current Accuracy at Room Temperature Accuracy at Minimum Temperature Accuracy at Maximum Temperature AV VOUTMAX Nonlinearity Line Regulation Average Slope of Output Voltage Maximum Output Voltage Test Conditions CE = VIL (Note 1) CE = VIH (Note 2) CE = VIH or VIL CE = step from VIH to VIL (Note 3) TA = – 20°C and +125°C TA = – 20°C and +100°C Circuit per Figure 1: R1 = 240kΩ VSS = – 12V (Note 1) TA = +25°C (Note 4) TC1023: TA = – 20°C TC1024: TA = – 20°C (Note 4) TC1023: TA = +100°C TC1024: TA = +125°C (Note 4) Note 5 TC1023: 2.2V ≤ VCC ≤ 12V TC1024: 3.0V ≤ VCC ≤ 12V (Note 1) Min Typ Max Unit 2.2 3.0 — — — 40 12 12 60 V µA — 1 5 µA 2.0 — –1 — — — — 400 — 0.8 +1 — V V µA µsec 270 – 230 — — 1780 1030 mV — –2 — — 1.0 +2 mA °C –4 — +4 °C –3 — +3 °C – 0.8 — — — — 80 10 — +0.8 — — VCC – 1.2 °C µV/V mV/°C V NOTES: 1. VOUT outputs open circuited. 2. VOUT is 0V through approximately 100kΩ to ground when CE = VIH. 3. Recovery time is the period required for VOUT to rise from 0V (shutdown state) to the voltage corresponding to the measured temperature driving a 100pF capacitive load. 4. Accuracy = Difference between calculated output voltage (10mV/°C x Device case temperature at specified temperature and power supply) and measured output voltage expressed in °C. 5. Nonlinearity = deviation of output voltage versus temperature from the best-fit straight line over the device rated temperature range. TC1023/1024-05 6/12/97 2 PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1024 DETAILED DESCRIPTION VCC = 3.0V to 12.0V A plot of output voltage versus temperature for both the TC1023 and TC1024 appears in Figure 5. The TC1023 can be used with single power supply to measure temperatures from 0°C to 100°C. A pull-down resistor (R1 in Figure 1) must be added from the output pin to the negative power supply for measuring temperatures less than 0°C. The value of the resistor must be chosen to limit the maximum current pulled from the output to the negative supply to – 50µA (i.e., R1 = VSS/50µA). VCC VOUT CE VOUT TC1024 GND Output Stage TC1024 (– 20°C to +125°C) Both devices have Class A output stages capable of sourcing 1mA. These devices have a limited ability to drive heavy capacitive loads. Loads of 50pF (to ground) can be driven directly. For heavier loads, a 2kΩ (or greater) resistor should be placed in series with the output for decoupling. If the TC1023/1024 is used in a noisy electrical environment, a 0.1µF bypass capacitor from VCC to GND is recommended. Figure 2. TC1024 Connections 2.5V REF VCC VCC A/D CONVERTER VOUT Shutdown/Calibrate Mode TC102x CE The TC1023/1024 enters shutdown when the CE input is taken to VIH. This causes quiescent current to fall to 1µA (typ) and the output to drop immediately to 0V through approximately 100kΩ. For applications where the TC1023/ 1024 is connected to an external A/D converter, a reference voltage can be directly connected to VOUT while in shutdown for A/D calibration, as shown in Figure 3. A CMOS gate provides bias voltage to the bandgap reference VR, and at the same time disables the TC102x by taking CE to VIH. Limiting resistor R1 should be chosen to limit current through the voltage reference to the desired current (IREF). That is, R1 = (VOH – VREF)/IREF (where VOH is the CMOS gate output high voltage at output current equal to IREF; and VREF is the reference voltage of VR). GND CMOS GATE R1 CAL Figure 3. A/D Calibration Multi-Zone Temperature Sensing The CE input facilitates multi-zone temperature sensing as shown in the example of Figure 4. In this example, the processor addresses either of two sensors with a single I/O port pin. The TC102x VOUT pins are connected together and routed to the processor's A/D converter, eliminating the need for separate A/D input channels for each sensor. VCC = 2.2V to 12.0V MIN. VCC MICROCONTROLLER VCC Zone 1 VCC VCC VOUT VOUT CE TC1023 VOUT VOUT TC102x CE GND A/D CONVERTER Zone 2 GND R1 = VSS /50µA TC102x CE GND Zone 1/Zone 2 I/O Pin VSS Figure 1. TC1023 Connections TC1023/1024-05 6/12/97 Figure 4. TC1023/1024 Addressing 3 PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1024 1.8 1.7 1.6 TC1023: VOUT = (10mV/°C) (Temperature °C) TC1024: VOUT = (10mV/°C) (Temperature °C) + 500mV 1.5 1.4 1.3 1.2 VOUT (VOLTS) 1.1 1.0 TC1024 0.9 0.8 0.7 TC1023 0.6 0.5 0.4 0.3 0.2 0.1 0 – 0.1 – 0.2 – 40 – 30 – 20 –10 0 10 20 30 40 50 60 70 TEMPERATURE (°C) Figure 5. Output Voltage vs. Temperature TC1023/1024-05 6/12/97 4 80 90 100 110 120 130 PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1024 PACKAGE DIMENSIONS 8-Pin SOIC PIN 1 .157 (3.99) .150 (3.81) .244 (6.20) .228 (5.79) .050 (1.27) TYP. .197 (5.00) .189 (4.80) .069 (1.75) .053 (1.35) .010 (0.25) .007 (0.18) 8°MAX. .018 (0.46) .010 (0.25) .014 (0.36) .004 (0.10) .050 (1.27) .016 (0.40) 8-Pin MSOP PIN 1 .122 (3.10) .114 (2.90) .197 (5.00) .187 (4.80) .026 (0.65) TYP. .122 (3.10) .114 (2.90) .043 (1.10) MAX. .016 (0.40) .010 (0.25) .008 (0.20) .005 (0.13) 6°MAX. .006 (0.15) .002 (0.05) .028 (0.70) .016 (0.40) Dimensions: inches (mm) TC1023/1024-05 6/12/97 5 PRELIMINARY INFORMATION PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE TC1023 TC1024 Sales Offices TelCom Semiconductor 1300 Terra Bella Avenue P.O. Box 7267 Mountain View, CA 94039-7267 TEL: 415-968-9241 FAX: 415-967-1590 E-Mail: [email protected] TC1023/1024-05 6/12/97 TelCom Semiconductor Austin Product Center 9101 Burnet Rd. Suite 214 Austin, TX 78758 TEL: 512-873-7100 FAX: 512-873-8236 6 TelCom Semiconductor H.K. Ltd. 10 Sam Chuk Street, Ground Floor San Po Kong, Kowloon Hong Kong TEL: 852-2324-0122 FAX: 852-2354-9957 Printed in the U.S.A.