10-Bit Digital Temperature Sensor a in 6-Lead SOT-23 AD7814 FEATURES FUNCTIONAL BLOCK DIAGRAM 10-Bit Temperature-to-Digital Converter 55 C to +125 C Operating Temperature Range BAND GAP 10-BIT 2 C Accuracy TEMPERATURE ANALOG/DIGITAL SPI- and DSP-Compatible Serial Interface SENSOR CONVERTER Shutdown Mode GND V DD Space-Saving SOT-23 Package TEMPERATURE AD7814 VALUE APPLICATIONS REGISTER Hard Disk Drives Personal Computers CS SERIAL Electronic Test Equipment SCLK BUS DIN Office Equipment INTERFACE DOUT Domestic Appliances Process Control GENERAL DESCRIPTION PRODUCT HIGHLIGHTS The AD7814 is a complete temperature monitoring system in a 1. The AD7814 has an on-chip temperature sensor that allows SOT-23 package or 8-lead MSOP package. It contains a band an accurate measurement of the ambient temperature. The gap temperature sensor and 10-bit ADC to monitor and digitize measurable temperature range is 55C to +125C, with a the temperature reading to a resolution of 0.25C. 2C temperature accuracy. The AD7814 has a flexible serial interface that allows easy inter- 2. Supply voltage of 2.7 V to 5.5 V facing to most microcontrollers. The interface is compatible 3. Space-saving 6-lead SOT-23 package and 8-lead MSOP with SPI , QSPI, and MICROWIRE protocol, and is also package compatible with DSPs. The part features a standby mode that is 4. 10-bit temperature reading to 0.25C resolution controlled via the serial interface. 5. Standby mode that reduces the current consumption to 1 A The AD7814s wide supply voltage range, low supply current, and SPI-compatible interface make it ideal for a variety of applications, including personal computers, office equipment, and domestic appliances. 2 Purchase of licensed I C components of Analog Devices or one of its sublicensed 2 Associated Companies conveys a license for the purchaser under the Philips I C 2 Patent Rights to use these components in an I C system, provided that the system 2 conforms to the I C Standard Specification as defined by Philips. REV. E Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. may result from its use. No license is granted by implication or otherwise Tel: 781/329-4700 www.analog.com under any patent or patent rights of Analog Devices. Trademarks and Fax: 781/326-8703 2004 Analog Devices, Inc. All rights reserved. registered trademarks are the property of their respective owners.1 AD7814SPECIFICATIONS (T = T to T , V = 2.7 V to 5.5 V, unless otherwise noted.) A MIN MAX DD Parameter Min Typ Max Unit Test Conditions/Comments TEMPERATURE SENSOR AND ADC 2 Accuracy 2.0 CT = 0C to 85C. V = 3 V to 5.5 V A DD 2 2.5 CT = 40C to 0C. V = 3 V to 5.5 V A DD 2.0 3.5 CT = 55C to +125C. V = 3 V to 5.5 V A DD Resolution 10 Bits Update Rate, t 400 s R Temperature Conversion Time 25 s SUPPLIES Supply Voltage 2.7 5.5 V For Specified Performance Supply Current Normal Mode 250 400 A Shutdown Mode (V = 5 V) 1.23 3 A DD Shutdown Mode (V = 3 V) 0.43 1 A DD Power Dissipation 80 WV = 3 V. Using Normal Mode DD Power Dissipation V = 3 V. Using Shutdown Mode DD 1 sps 3.7 W 10 sps 3.9 W 100 sps 5.8 W 3 DIGITAL INPUT Input High Voltage, V 2.4 V IH Input Low Voltage, V 0.8 V IL Input Current, I 1 AV = 0 V to V IN IN DD Input Capacitance, C 10 pF All Digital Inputs IN 3 DIGITAL OUTPUT Output High Voltage, V V 0.3 V I = I = 200 A OH DD SOURCE SINK Output Low Voltage, V 0.4 V I = 200 A OL OL Output Capacitance, C 50 pF OUT NOTES 1 All specifications apply for 55C to +125C unless otherwise stated. 2 For V = 2.7 V to 3 V and T = 40C to +85C, the typical temperature error is 2C. DD A 3 Guaranteed by design and characterization, not production tested. Specifications subject to change without notice. 1, 2, 3 TIMING CHARACTERISTICS (T = T to T , V = 2.7 V to 5.5 V, unless otherwise noted.) A MIN MAX DD Parameter Limit Unit Comments t 0 ns min CS to SCLK Setup Time 1 t 50 ns min SCLK High Pulse Width 2 t 50 ns min SCLK Low Pulse Width 3 4 t 35 ns max Data Access Time After SCLK Falling Edge 4 t 20 ns min Data Setup Time Prior to SCLK Rising Edge 5 t 0 ns min Data Hold Time After SCLK Rising Edge 6 t 0 ns min CS to SCLK Hold Time 7 4 t 40 ns max CS to DOUT High Impedance 8 NOTES 1 Guaranteed by design and characterization, not production tested. 2 All input signals are specified with tr = tf = 5 ns (10% to 90% of V ) and timed from a voltage level of 1.6 V. DD 3 See Figure 2. 4 Measured with the load circuit of Figure 1. Specifications subject to change without notice. 2 REV. E