GMT G786 ±1c remote and local temperature sensor with smbus serial interface Datasheet

G786
Global Mixed-mode Technology Inc.
±1°C Remote and Local Temperature Sensor with
SMBus Serial Interface
Features
General Description
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The G786 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.
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Two Channels: Measures Both Remote and
Local Temperatures
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
+3V to +5.5V Supply Range
Small 8-Lead SOP and MSOP Package
Remote Temperature Measurment up to 160°C
by using offset shifting method (see “Measure
Remote Temperature Higher Than 127°C” section)
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.
Applications
Desktop and Notebook
Computers
Smart Battery Packs
LAN Servers
Industrial Controllers
Central Office
Telecom Equipment
Test and Measurement
Multi-Chip Modules
The G786 and G786-1 have the same functions but
different SMBus slave addresses. This allows for one
of each to be on the bus at the same time.
The G786 is available in a small, 8-pin SOP and
MSOP surface-mount package.
Ordering Information
ORDER
NUMBER
MARKING
TEMP.
RANGE
PACKAGE
(Green)
G786P11U
G786
-55°C to +125°C
SOP-8
G786P81U
G786-1P81U
G786
G786-1
-55°C to +125°C
-55°C to +125°C
MSOP-8
MSOP-8
Note:P1:SOP-8
P8:MSOP-8
1: Bonding Code
U: Tape & Reel
Pin Configuration
Typical Application Circuit
3V TO 5.5V
0.1µF
G786/G786-1
VCC
1
8
SMBCLK
DXP
2
7
SMBDATA
VCC
DXP
10kΩ EACH
SMBCLK
SMBDATA
*DXN
3
6
ALERT
DXN
2N3904
THERM
4
5
ALERT
CLOCK
DATA
INTERRUPT TO µC
2200pF
THERM
GND
GND
SOP-8/MSOP-8
*: DXN : DXN is internally connected to GND.
Ver: 0.3
Apr 29, 2009
TEL: 886-3-5788833
http://www.gmt.com.tw
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