G780 Global Mixed-mode Technology Inc. ±1°C Remote and Local Temperature Sensor with SMBus Serial Interface Features General Description Two Channels: Measures Both Remote and Local Temperatures Measure Thermal Diode with a Transistor Model No Calibration Required Built-in Noise-Buster for Remote Sensor SMBus 2-Wire Serial Interface Programmable Under/Overtemperature Alarms Supports SMBus Alert Response Accuracy: ±1°C (+60°C to +100°C, remote) ±3°C (+60°C to + 100°C, local) 320µA (typ) Average Supply Current During Conversion Measure Thermal Diode with Transistor Model Support 45nm, 65nm and 90nm CPU thermal diode +3V to +5.5V Supply Range Small 8-Lead SOP , MSOP and TDFN Package Remote Temperature Measurment up to 160°C by using offset shifting method (see “Measure Remote Temperature Higher Than 127°C” section) The G780 is a precise digital thermometer that reports the temperature of both a remote sensor and its own package. The remote sensor is a diode-connected transistor typically a low-cost, easily mounted 2N3904 NPN type that replace conventional thermistors or thermocouples. Remote accuracy is ±1°C with no calibration needed. It also has a build-in noise filtering function in remote sensor measuring the diode temperature. The remote channel can also measure the die temperature of other ICs, such as microprocessors, that contain an on-chip, diode-connected transistor. The 2-wire serial interface accepts standard System Management Bus (SMBus) Write Byte, Read Byte, Send Byte, and Receive Byte commands to program the alarm thresholds and to read temperature data. The data format is 11bits plus sign, with each bit corresponding to 0.125°C, in two’s-complement format. Measurements can be done automatically and autonomously, with the conversion rate programmed by the user or programmed to operate in a single-shot mode. The adjustable rate allows the user to control the supply current drain. The G780 is available in a small, 8-pin SOP, MSOP and TDFN surface-mount package. Applications Desktop and Notebook Computers Smart Battery Packs LAN Servers Industrial Controllers Central Office Telecom Equipment Test and Measurement Multi-Chip Modules Ordering Information ORDER NUMBER MARKING TEMP. RANGE PACKAGE (Pb free) G780P11U G780P81U G780RD1U G780-1P11U G780-1P81U G780 G780 780 G780-1 G780-1 -55°C to +125°C -55°C to +125°C -55°C to +125°C -55°C to +125°C -55°C to +125°C SOP-8 MSOP-8 TDFN3X3-8 SOP-8 MSOP-8 Note:P1:SOP-8 P8:MSOP-8 RD:TDFN3X3-8 1: Bonding Code U: Tape & Reel Pin Configuration Typical Application Circuit 3V TO 5.5V 0.1µF G780/G780-1 VCC DXP DXN G780 8 1 7 2 3 6 VCC SMBCLK SMBDATA ALERT VCC 1 DXP 2 DXN 3 THERM THERM 4 5 SOP-8/MSOP-8 Thermal Pad 4 8 SMBCLK 7 SMBDATA 6 ALERT 5 GND DXP 10kΩ EACH SMBCLK SMBDATA DXN 2N3904 GND ALERT CLOCK DATA INTERRUPT TO µC 2200pF THERM GND TDFN3X3-8 Note: Recommend connecting the Thermal Pad to the GND or let it keep floating. Ver: 0.5 Oct 02 , 2008 TEL: 886-3-5788833 http://www.gmt.com.tw 1