G751-2 [ETC]
Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface; 数字温度传感器和热看门狗具有双线接口![G751-2](http://pdffile.icpdf.com/pdf1/p00052/img/icpdf/G751-2_271986_icpdf.jpg)
型号: | G751-2 |
厂家: | ![]() |
描述: | Digital Temperature Sensor and Thermal Watchdog with Two-Wire Interface |
文件: | 总10页 (文件大小:162K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
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Global Mixed-mode Technology Inc.
G751
Digital Temperature Sensor and Thermal Watchdog
with Two-Wire Interface
General Description
Features
ꢀSMBus interface
ꢀProgrammable Trip Point (TOS) and Hysteresis
The G751 is a temperature sensor, Delta-Sigma
analog-to-digital converter, and digital over- tem-
perature detector with SMBus interface. The host
can query the G751 at any time to read temperature.
The open-drain Over temperature Shutdown (O.S.)
output becomes active when the temperature ex-
ceeds a programmable limit. This pin can operate in
either “Comparator” or “Interrupt” mode.
(THYST
)
ꢀSeparate open-drain output pin operates as
interrupt or comparator at output
ꢀRegister readback capability
ꢀPower up defaults permit stand-alone opera-
tion as thermostat
The host can program both the temperature alarm
threshold (TOS) and the temperature at which the
alarm condition goes away (THYST). In addition, the
host can read back the contents of the G751’s TOS
and THYST registers. The sensor powers up in Com-
parator mode with default thresholds of 50°C TOS
45°C THYST. for G751-1 and 80°C TOS , 75°C THYST
for G751-2.
ꢀShutdown mode to minimize power consump-
tion
ꢀUp to 8 G751s can be connected to a single
bus
Key Specifications
ꢀSupply Voltage
ꢀSupply Current
3.0V to 5.5V
280µA (typ)
1mA (max)
2µA(typ)
operating
Ordering Information
shutdown
ꢀTemperature Accuracy
-25°C to 100°C
-55°C to 125°C
PART
T
OS THYST
Transport Media
PACKAGE
8 SOP
±2°C (max)
±3°C (max)
G751-1 50°C/45°C 2500 Units on Tape and Reel
G751-2 80°C /75°C 2500 Units on Tape and Reel
8 SOP
Applications
ꢀSystem Thermal Management
ꢀPersonal Computers
ꢀOffice Electronics
ꢀElectronic Test Equipment
Typical Application
Pin Configuration
+VS 3V to 5.5V
Typical Bypass 0.1 µF
(Unless mounted close
to Processor)
G751
8
7
6
5
SMBDATA
SMBCLK
O.S.
1
2
8
7
6
+Vs
A0
A0
A1
A2
Address(Set as
desired)
3
To Processor
Interrupt Line
G751
3
4
O.S. Out
A1
A2
1
2
SMBDATA
SMBCLK
Interface
5
GND
4
8Pin SOP
O.S. Set for active low for
wire OR’d multiple
interrupt line
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver: 2.2
Nov 07 2001
1
Global Mixed-mode Technology Inc.
G751
Absolute Maximum Ratings.
Operating Ratings
Specified Temperature Range…………….TMIN to TMAX
Supply Voltage………….…………………-0.3V to 6.5V
Voltage at any Pin……………….…-0.3V to +Vs +0.3V
Input Current at any Pin…………………………….5mA
Package Input Current…………………………….20mA
O.S. Output Sink Current………………………….10mA
O.S. Output Voltage…………………….…………..6.5V
Storage Temperature…………………-65°C to +150°C
Soldering Information, Lead Temperature
SOP Package
-55°C to +125°C
Supply Voltage Range (+Vs)…………..+3.0V to +5.5V
Vapor Phase (60 seconds)……………………….215°C
Infrared (15 seconds)……………………………..220°C
ESD Susceptibility
Human Body Model……………………………….2000V
Machine
Model……………………………………...200V
Temperature-to-Digital Converter Characteristics
Unless otherwise noted, these specifications apply for +Vs=+3.3v Vdc. Boldface limits apply for TA=TJ=TMIN to
TMAX; all other limits TA=TJ= +25°C, unless otherwise noted.
PARAMETER
CONDITIONS
TA=-25°C to +100°C
TA=-55°C to +125°C
TYPICAL
LIMITS
UNITS
±
±
Accuracy
2.0
°C (max)
3.0
Resolution
9
Bits
Temperature Conversion Time
Quiescent Current
100
0.25
Ms
SMBus Inactive
SMBus Active
Shutdown Mode
IOUT = 4.0mA
Ma
mA (max)
1.0
1
µA
O.S. Output Saturation Voltage
O.S. Delay
V (max)
0.8
1
Conversions (min)
Conversions (max)
6
TOS Default Temperature G751-1/G751-2
THYST Default Temperature G751-1/G751-2
50/80
45/75
°C
°C
Block Diagram
+VS 3.0V - 5.5V
8
Temperature
3
O.S.
Threshold
9-Bit Delta-Sigma
Analog-to-Digital
Converter
Set Point
Comparator
TOS Set Point
Register
Reset
Silicon
Bandgap
Temperature
Sensor
Pointer
Register
Configuration
Register
THYST Set Point
Register
7
A0
6
1
2
SMBDATA
SMBCLK
Two-Wire Interface
4
A1
5
A2
TEL: 886-3-5788833
http://www.gmt.com.tw
Ver: 2.2
Nov 07 2001
2
Global Mixed-mode Technology Inc.
G751
Logic Electrical Characteristics
Digital DC Characteristics
Unless otherwise noted, these specifications apply for +Vs=+3.3 Vdc. Boldface limits apply for TA=TJ=TMIN to
TMAX; all other limits TA=TJ=+25°C, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
TYPICAL
LIMITS
UNITS
V (min)
V (max)
V (min)
V (max)
µA
×
+Vs 0.7
VIN (1)
Logical “1” Input Voltage
+Vs + 0.5
-0.3
VIN (0)
Logical “0” Input Voltage
×
+Vs 0.3
IIN (1)
IIN (0)
CIN
Logical “1”Intput Current
Logical “0”Intput Current
All Digital Inputs
VIN=5V
VIN=0V
0.005
-0.005
20
1.0
µA
-1.0
PF
IOH
High Level Output Current
Low Level Output Voltage
Output Fall Time
VOH=5V
IOL=3ma
µA (max)
V (max)
ns (max)
100
0.4
VOL
tOF
CL=400pF,IO=3ma
250
SMBus Digital Switching Characteristics
Unless otherwise noted, these specifications apply for +Vs = +3.3 Vdc and CL (load capacitance) on output lines =
80pF unless otherwise specified. Boldface limits apply for TA = TJ = TMIN to TMAX; all other limits TA = TJ = +25°C,
unless otherwise noted.
The switching characteristics of the G751 fully meet or exceed the published specifications of the SMBus. The
following parameters are the timing relationships between SMBCLK and SMBDATA signals related to the G751.
They are not the SMBus specifications.
SYMBOL
PARAMETER
CONDITIONS TYPICAL LIMITS UNITS
t1
t2
t3
t4
t5
SMBCLK (Clock) Period
2.5
100
0
µs (min)
ns (min)
ns (min)
ns (min)
ns (min)
Data in Set-Up Time to SMBCLK High
Data Out Stable after SMBCLK Low
SMBDATA Low Set-Up Time to SMBCLK Low (Start Condition)
SMBDATA High Hold Time after SMBCLK High (Stop Condition)
100
100
Pin Description
PIN LABEL
FUNCTION
TYPICAL CONNECTION
1
SMBDATA SMBus Serial Bi-Directional Data Line
SMBCLK SMBus Clock Input
From Controller
2
3
From Controller
O.S.
Overtemperature Shutdown Open Drain Output
Power Supply Ground
Pull Up Resistor, Controller Interrupt Line
Ground
4
GND
5,6,7
8
A0-A2 User-Set SMBus Address Inputs
Ground (Low, “0”) or +Vs (High, “1”)
DC Voltage from 3V to 5.5V
+Vs
Positive Supply Voltage Input
t1
SMBCLK
t5
t4
SMBDATA
Data in
t2
SMBDATA
Data out
t3
Logic Electrical Characteristics
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
3
Global Mixed-mode Technology Inc.
G751
0,1111,1010
+25°C
+0.5°C
0,0011,0010
0,0000,0001
Temperature
0,0000,0000
0°C
-55°C
1,1111,1111
1,1100,1110
+125°C
-0.5°C
1,1001,0010
-25°C
Temperature-to-Digital Transfer Function (Non-linear scale for clarity)
Default Modes
Functional Description
G751 always powers up in a known state. G751
power up default conditions are:
1. Comparator mode
2. TOS set to 50°C for G751-1, to 80°C for G751-2
3. THYST set to 45°C for G751-1, to 75°C for G751-2
4. O.S. active low
5. Pointer set to “00”; Temperature Register
With these operating conditions G751 can act as a
stand-alone thermostat with the above temperature
settings. Connection to an SMBus is not required.
The G751 temperature sensor incorporates
a
band-gap type temperature sensor and 9-bit ADC
(Delta-Sigma Analog- to-Digital Converter). The
temperature data output of the G751 is available at
all times via the SMBus. If a conversion is in pro-
gress, it will be stopped and restarted after the read.
A digital comparator is also incorporated that com-
pares a series of readings, the number of which is
user-selectable, to user-programmable setpoint and
hysteresis values. The comparator trips the O.S.
output line, which is programmable for mode and
polarity.
SMBus Interface
The G751 operates as a slave on the SMBus, so the
SMBCLK line is an input (no clock is generated by
the G751) and the SMBDATA line is a bi-directional
serial data path. According to SMBus specifications,
the G751 has a 7-bit slave address. The four most
significant bits of the slave address are hard wired
inside the G751 and are “1001”. The three least sig-
nificant bits of the address are assigned to pins
A2-A0, and are set by connecting these pins to
ground for a low, (0); or to +Vs for a high, (1).
O.S. Output, TOS and THYST Limits
In Comparator mode the O.S. Output behaves like a
thermostat. The output becomes active when tem-
perature exceeds the TOS limit, and leaves the active
state when the temperature drops below the THYST
limit. In this mode the O.S. output can be used to
turn a cooling fan on, initiate an emergency system
shutdown, or reduce system clock speed. Shutdown
mode does not reset O.S. state in a comparator
mode.
Therefore, the complete slave address is:
In interrupt mode exceeding TOS also makes O.S.
active but O.S. will remain active indefinitely until
reset by reading any register via the SMBus inter-
face. Once O.S. has been activated by crossing TOS,
then reset, it can activated again only by Tempera-
ture going below THYST. Again, it will remain active
indefinitely until being reset by a read. Placing the
G751 in shutdown mode also resets the O.S. output.
1
0
0
1
A2
A1
A0
MSB
LSB
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
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Global Mixed-mode Technology Inc.
G751
Shutdown Mode
Shutdown mode is enabled by setting the shutdown
bit in the Configuration register via the SMBus. Shut-
down mode reduces power supply current to 1 µA
typical. In interrupt mode O.S. is reset if previously
set and is undefined in Compatator mode during
shutdown. The SMBus interface remains active. Ac-
tivity on the clock and data lines of the SMBus may
slightly increase shutdown mode quiescent current.
TOS, THYST, and Configuration registers can be read
from and written to in shutdown mode.
*
*
*
Fault Queue
A fault queue of up to 6 faults is provided to prevent
false tripping of O.S. when the G751 is used in noisy
environments. The number of faults set in the queue
must occur consecutively to set the O.S. output.
Comparator/Interrupt Mode
As indicated in the O.S. Output Temperature Re-
sponse Diagram, Figure 1, the events that trigger
O.S. are identical for either Comparator or Interrupt
mode. The most important difference is that in Inter-
rupt mode the O.S. will remain set indefinitely once it
has been set. To reset O.S. while in Interrupt mode,
perform a read from any register in the G751.
O.S. Output
The O.S. output is an open-drain output and does
not have an internal pull-up. A ”high” level will not be
observed on this pin until pull-up current is provided
from some external source, typically a pull-up resis-
tor. Choice of resistor value depends on many sys-
tem factors but, in general, the pull-up resistor
should be as large as possible. This will minimize
any errors due to internal heating of the G751. The
maximum resistance of the pull up, based on G751
specification for High Level Output Current, to pro-
vide a 2V high level, is 30kΩ.
Figure1 O.S. Output Temperature Response Diagram
Temperature Data Format
Temperature data can be read from the Temperature,
TOS Set Point, and THYST Set Point registers; and
written to the TOS Set Point, and THYST Set Point reg-
isters. Temperature data is represented
by a 9-bit, two’s complement word with an LSB
(Least Significant Bit) equal to 0.5°C:
O.S. Polarity
DIGITAL OUTPUT
TEMPERATURE
The O.S. output can be programmed via the con-
figuration register to be either active low (default
mode), or active high. In active low mode the O.S.
output goes low when triggered exactly as shown on
the O.S. Output Temperature Response Diagram,
Figure 1. Active high simply inverts the polarity of the
O.S. output.
BINARY
HEX
0FAh
032h
001h
000h
1FFh
1CEh
192h
+125°C
+25°C
+0.5°C
0°C
-0.5°C
-25°C
-55°C
0 1111 1010
0 0011 0010
0 0000 0001
0 0000 0000
1 1111 1111
1 1100 1110
1 1001 0010
TEL: 886-3-5788833
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Ver: 2.2
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Global Mixed-mode Technology Inc.
Internal Register Structure
G751
SMBDATA
SMBCLK
Interface
Data
Address
Pointer Register
(Selects register for
communication
Register Select
Configuration
(Read-write, sets operating
Mode)
Temperature
(Read-only)
Pointer = 00000000
Pointer = 00000001
TOS Set Point
(Read-write)
THYST Set Point
(Read-write)
Pointer = 00000011
Pointer = 00000010
There are four data registers in the G751, selected
by the Pointer register. At power-up the Pointer is set
to “00”; the location for the Temperature Register.
The Pointer register latches whatever the last loca-
tion it was set to. In Interrupt Mode, a read from the
G751, or placing the device in shutdown mode, re-
sets the O.S. output. All registers are read and write,
except the Temperature register which is read only.
The first data byte is the most significant byte with
most signification bit first, permitting only as much
data as necessary to be read to determine tempera-
ture condition. For instance, if the first four bits of the
temperature data indicates an overtemperature con-
dition, the host processor could immediately take
action to remedy the excessive temperatures. At the
end of a read, the G751 can accept either Acknowl-
edge or No Acknowledge from the Master (No Ac-
knowledge is typically used as a signal for the salve
that the Master has read its last byte).
A write to the G751 will always include the address
byte and the Pointer byte. A write to the Configura-
tion register requires one data byte, and the TOS and
T
HYST registers require two data bytes.
An inadvertent 8-bit read from a 16-bit register, with
the D7 bit low, can cause the G751 to stop in a state
where the SDA line is held low as shown in Figure 2.
This can prevent any further bus communication until
at least 9 additional clock cycles have occurred. Al-
ternatively, the master can issue clock cycles until
SDA goes high, at which time issuing a “Stop” condi-
tion will reset the G751.
Reading the G751 can take place either of two ways:
If the location latched in the Pointer is correct (most
of the time it is expected that the Pointer will point to
Temperature register because it will be the data
most frequently read from the G751), then the read
can simply consist of an address byte, followed by
retrieving the corresponding number of data bytes. If
the Pointer needs to be set, than an address byte,
pointer byte, repeat start, and another address byte
will accomplish a read.
SMBCLK
SMBDATA
A2
A1
A0
D7
D15
D14
D6
D5
D4
D3
D2
D1
D0
D13
D12
D11
D10
D9
D8
R/W
Bit
Stop
Cond
by
Ack
by
Master
Ack
by
G751
Ack
by
Master
Master
Start
by
Master
Address Byte
Most Significant
Data Byter
Master detects the error
of its ways
Intended Stop by
Master but G751 locks SMBDATA low
Figure 2. Inadvertent 8-Bit Read from 16-Bit Register where D7 is Zero
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
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Global Mixed-mode Technology Inc.
Pointer Register
(Selects which registers will be read from or written to):
G751
P7
P6
P5
P4
P3
P2
P1
P0
0
0
0
0
0
0
Register Select
P0-P1 :Register Select:
P1
0
P0
0
REGISTER
Temperature (Read only) (Power-up default)
Configuration (Read/Write)
THYST (Read/Write)
0
1
1
0
1
1
TOS (Read/Write)
P2-P7 :Must be kept zero.
Temperature Register
(Read Only):
D15 D14 D13 D12 D11 D10
MSB Bit 7 Bit 6 Bit 5 Bit 4 Bit 3
D0-D6 :Undefined
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Bit 2
Bit 1
LSB
X
X
X
X
X
X
X
D7-D15 :Temperature Data. One LSB = 0.5°C. Two’s complement format.
Configuration Register
(Read/Write):
D7
D6
D5
D4
D3
Fault Queue
D2
O.S. Polarity
D1
Cmp/Int
D0
Shutdown
0
0
0
Power up default is with all bits “0” (zero).
D0 :Shutdown : When set to 1 the G751 goes to low power shutdown mode.
D1 :Comparator / Interrupt mode : 0 is Comparator mode, 1 is Interrupt mode.
D2 :O.S. Polarity : 0 is active low, 1 is active high. O.S. is an open-drain output under all conditions.
D3-D4 :Fault Queue : Number of faults necessary to detect before setting O.S. output to avoid false tripping due
to noise :
D4
0
D3
0
NUMBER OF FAULTS
1 (Power-up default)
0
1
2
4
6
1
0
1
1
D5-D7 :These bits are used for production testing and must be kept zero for normal operation.
T
HYST and TOS Register
(Read/Write):
D15 D14 D13 D12 D11 D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
MSB Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
LSB
X
X
X
X
X
X
X
D0-D6 :Undefined
D7-D15 :THYST Or TOS Trip Temperature Data. Power up default is TOS = 50°C /80°C for G751-1/G751-2, THYST
45°C /75°C for G751-1/G751-2.
=
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
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Global Mixed-mode Technology Inc.
G751
SMBus Timing Diagrams
1
1
9
9
1
9
A1
D4
D3
1
0
0
1
A2
A0
D7
D5
D2
D1
D0
D7
D6
D6
D5
D4
D3
D2
D1
D0
R/W
Start
by
Master
Ack
by
G751
Ack
by
Master
No Ack
by
Master
Stop
Cond
by
Master
Address Byte
Most Significant Data Byte
Least Significant Data Byte
1
1
9
9
A1
D1
D0
1
0
0
1
A2
A0
R/W
0
0
0
0
0
0
Start
by
Master
Ack
by
G751
Ack
by
G751
Address Byte
Pointer Byte
1
1
1
9
9
1
9
A1
D4
D3
0
0
1
A2
A0
D7
D5
D2
D1
D0
D7
D6
D6
D5
D4
D3
D2
D1
D0
R/W
Ack
by
G751
Ack
by
Master
No Ack
by
Master
Stop
Cond
by
Repeat
Start
by
Master
Address Byte
Most Significant Data Byte
Least Significant Data Byte
Master
1
1
1
9
9
D6
D3
D2
A1
D7
D5
D4
D0
0
0
1
A2
A0
R/W
D1
Start
by
Master
Ack
by
G751
Stop
Cond
by
Ack
by
G751
Master
Address Byte
Pointer Byte
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
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Global Mixed-mode Technology Inc.
G751
Timing Diagrams (Continued)
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
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Global Mixed-mode Technology Inc.
G751
Package Information
C
E
H
L
D
θ
7 ° (4X)
A2
A1
A
y
e
B
Note:
1. Package body sizes exclude mold flash and gate burrs
2. Dimension L is measured in gage plane
3. Tolerance 0.10mm unless otherwise specified
4. Controlling dimension is millimeter converted inch dimensions are not necessarily exact.
DIMENSION IN MM
DIMENSION IN INCH
SYMBOL
MIN.
1.35
0.10
-----
0.33
0.19
4.80
3.80
-----
5.80
0.40
-----
0º
NOM.
1.60
-----
1.45
-----
-----
-----
-----
1.27
-----
-----
-----
-----
MAX.
1.75
0.25
-----
MIN.
0.053
0.004
-----
NOM.
0.063
-----
MAX.
0.069
0.010
-----
A
A1
A2
B
0.057
-----
0.51
0.25
5.00
4.00
-----
0.013
0.007
0.189
0.150
-----
0.020
0.010
0.197
0.157
-----
C
D
E
-----
-----
-----
e
0.050
-----
H
L
6.20
1.27
0.10
8º
0.228
0.016
-----
0.244
0.050
0.004
8º
-----
y
θ
-----
0º
-----
Taping Specification
Feed Direction
Typical SOP Package Orientation
TEL: 886-3-5788833
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Ver: 2.2
Nov 07 2001
10
相关型号:
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