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
G780
8
1
VCC
SMBCLK
VCC
DXP
DXN
7
2
3
6
ALERT
DXP
2
DXN
SMBDATA
1
3
THERM
THERM
4
5
SOP-8/MSOP-8
8
4
7
SMBDATA
6
ALERT
5
Thermal
Pad
GND
10kΩ EACH
SMBCLK
DXP
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: 0.4
Feb 20 , 2008
TEL: 886-3-5788833
http://www.gmt.com.tw
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