G7932 Datasheet, PDF (1/1 Pages) Global Mixed-mode Technology Inc – Two Remote and One Local Temperature Sensors and 3/4 Fan Controllers with SMBus Interface

Global Mixed-mode Technology Inc.
G7931/G7932
Two Remote and One Local Temperature Sensors
and 3/4 Fan Controllers with SMBus Interface
Features
„ Measures Two Remote and One Local Tempera-
tures
„ Adjustable Offset for Each Sensor via SMBus
„ Accuracy: Remote ±1°C (+20°C to +80°C)
±3°C (-10°C to +120°C)
„ +4.5V to +5.5V Supply Range
„ Alert Signal for Diode Fault, Fan Fail, and Fan
Out of Control
„ Supports SMBus Alert Response
„ Fan Drivers Using Linear Control Algorithm
„ Closed Loop Speed Control and programmable
8 Bits Open Loop Voltage Control for Fan
„ Wide speed control range for Fan, Accuracy
within 2%, when FANx_SET_CNT > 50
„ Internal Current-limit and Over-temperature
Protection for the Fan Controllers
„ Build-In Inverters for Driving Crystal
„ Optional Internal Clock Accuracy ±3% from 20°C to
80°C at 5V VCC
„ 20-Pin TSSOP Package
Applications
„ Projector, LCD TV, PDP TV
„ Desktop and Notebook
„ Central Office Computers
„ Telecom Equipments
„ Industrial Controls
„ LAN Servers
General Description
The G7931/G7932 contains 3 precise digital thermometers,
3/4 fan controllers, fan failure detection.
The thermometers report the temperature of 2 remote sen-
sors and 1 local sensor. The remote sensors are di-
ode-connected transistors typically a low-cost, easily
mounted 2N3904 NPN type or the diode built-in in CPU.
Remote accuracy is ±1°C for multiple transistor manufac-
turer. Local accuracy is ±3°C. The G7931/G7932 also sup-
port offset adjust function via SMBus to fix the error due to
different CPU diode or parasitic resistors.
The 2-wire serial interface accepts standard System Man-
agement Bus (SMBus^TM) Write Byte, Read Byte, Send
Byte, and Receive Byte commands. The SMBus address
is 70h 72h for write and 7173hh for read for G7932.For
G7931, ADD0 pin selects 3 different SMBus addresses.
(see “ SMBus Digital Interface” section)
G7931/G7932 contains 3/4 fan controllers which perform
closed-loop and open-loop control. G7931/ G7932 deter-
mines the current fan speed based on the FG inputs and an
externally supplied 32.768kHz clock. The driving ability is
5mA. G7931/G7932 also provides ALERT for fan fail and out
of control event.
SMBus^TM is a trademark of Intel Corp
Ordering Information
ORDER
NUMBER
G7931D51U
G7932D51U
Note: D5: TSSOP-20
1: Bonding Code
U: Tape & Reel
MARKING
G7931
G7932
TEMP.
RANGE
-55°C to +125°C
-55°C to +125°C
PACKAGE
(Green)
TSSOP-20
TSSOP-20
GMT Inc. does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and GMT Inc. reserves the right at
any time without notice to change said circuitry and specifications.
Pin Configuration
FAN2 1
FG2 2
FAN1 3
FG1 4
ALERT 5
NC 6
DXP1 7
SGND1 8
DXP2 9
SGND2 10
G7931
20 FAN3
19 FG3
18 NC
17 ADD0
16 GND
15 VCC
14 SCL
13 SDA
12 X2
11 X1/CLK
FAN2 1
FG2 ²
FAN1 3
FG1 ⁴
ALERT 5
NC 6
DXP1 7
SGND1 8
DXP2 9
SGND2 10
G7932
20 FAN3
19 FG3
18 FAN4
17 FG4
16 GND
15 VCC
14 SCL
13 SDA
12 X2
11 X1/CLK
TSSOP-20
TSSOP-20
Ver: 1.3
Oct 18, 2010
TEL: [phone]
http://www.gmt.com.tw
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