LM64
±
1˚C Remote Diode Temperature Sensor with PWM Fan Control and 5 GPIO’s
December 2003
LM64
±
1˚C Remote Diode Temperature Sensor with PWM Fan
Control and 5 GPIO’s
General Description
The LM64 is a remote diode temperature sensor with PWM
fan control. The LM64 accurately measures its own tempera-
ture and that of a remote diode. The LM64 remote tempera-
ture accuracy is factory trimmed for a MMBT3904 diode-
connected transistor with a 16˚C offset for high
temperatures. T
ACTUAL DIODE JUNCTION
= T
LM64
+ 16˚C
The LM64 features a PWM, open-drain, fan control output, 5
GPIO (General Purpose Input/Output) and 5 GPD (General
Purpose Default) pins. The 8-step Lookup Table allows for a
non-linear fan speed vs. temperature transfer function often
used to quiet acoustic fan noise.
Key Specifications
n
Remote Diode Temperature Accuracy (includes
quantization error)
Ambient Temp
30˚C to 50˚C
0˚C to 85˚C
Diode Temp
120˚C to 140˚C
25˚C to 140˚C
Max Error
±
1.0˚C (max)
±
3.0˚C (max)
n
Local Temp Accuracy (includes quantization error)
Ambient Temp
25˚C to 125˚C
n
Power Supply Requirements
Max Error
±
3.0˚C (max)
Features
n
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n
n
n
n
n
n
Accurately senses remote and local diode temperatures
Integrated PWM fan speed control output
Programmable 8-step Lookup Table for quieting fans
ALERT and T_Crit open-drain outputs
Tachometer input for measuring fan RPM
10 bit plus sign remote diode temperature data format,
with 0.125˚C resolution
SMBus 2.0 compatible interface, supports TIMEOUT
5 General Purpose Input/Output pins
5 General Purpose Default input pins
24-pin LLP package
Supply DC Voltage
Supply DC Current
3.0 V to 3.6 V
1.1 mA (typ)
Applications
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Computer Processor Thermal Management
Graphics Processor Thermal Management
Voltage Regulator Modules
Electronic Instrumentation
Power Supplies
Projectors
Connection Diagram
20065501
© 2003 National Semiconductor Corporation
DS200655
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LM64
Pin Descriptions
Pin
1
2
3
4
Name
GPIO1
GPIO2
GPIO3
PWM
Input/Output
Digital Input/
Open-Drain Output
Digital Input/
Open-Drain Output
Digital Input/
Open-Drain Output
Open-Drain
Digital Output
Function and Connection
General Purpose Open-Drain Digital Output or Digital Input. Typical pull-up
resistor is 10 kΩ to V
DD
.
General Purpose Open-Drain Digital Output or Digital Input. Typical pull-up
resistor is 10 kΩ to V
DD
.
General Purpose Open-Drain Digital Output or Digital Input. Typical pull-up
resistor is 10 kΩ to V
DD
.
Open-Drain Digital Output. Connect to fan drive circuitry. The power-on
default for this pin is low (pin 4 pulled to ground).
Connect to a low-noise +3.3
±
0.3 VDC power supply, and bypass to GND
with a 0.1 µF ceramic capacitor in parallel with a 100 pF ceramic capacitor.
A bulk capacitance of 10 µF needs to be in the vicinity of the LM64’s V
DD
pin.
Connect to the anode (positive side) of the remote diode. A 2.2 nF ceramic
capacitor must be connected between pins 6 and 7.
Connect to the cathode (negative side) of the remote diode. A 2.2 nF
ceramic capacitor must be connected between pins 6 and 7.
Open-Drain Digital Output. Typical pull-up resistor is 3 kΩ to V
DD
.
No Connection.
No Connection.
No Connection.
SMBus Address Select pin. If High, the SMBus address is 0x4E or, if Low,
the SMBus address is 0x18. Typical pull-up resistor is 10 kΩ to V
DD
.
This is the analog and digital ground return.
This pin is an open-drain ALERT Output. Typical pull-up resistor is 3 kΩ to
V
DD
.
This pin is a digital tachometer input. Typical pull-up resistor is 3 kΩ to
V
DD
.
This is the bi-directional SMBus data line. Typical pull-up resistor is 1.5 kΩ
to V
DD
.
This is the SMBus clock input. Typical pull-up resistor is 1.5 kΩ to V
DD
.
General Purpose Open-Drain Digital Output or Digital Input. Typical pull-up
resistor is 10 kΩ to V
DD
.
General Purpose Open-Drain Digital Output or Digital Input. Typical pull-up
resistor is 10 kΩ to V
DD
.
General Purpose Default Input Pin. Typical pull-up resistor is 10 kΩ to V
DD
.
Always connect to a logical High or Low level.
General Purpose Default Input Pin. Typical pull-up resistor is 10 kΩ to V
DD
.
Always connect to a logical High or Low level.
General Purpose Default Input Pin. Typical pull-up resistor is 10 kΩ to V
DD
.
Always connect to a logical High or Low level.
General Purpose Default Input Pin. Typical pull-up resistor is 10 kΩ to V
DD
.
Always connect to a logical High or Low level.
General Purpose Default Input Pin. Typical pull-up resistor is 10 kΩ to V
DD
.
Always connect to a logical High or Low level.
5
V
DD
Power Supply Input
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
D+
D-
T_Crit
N/C
N/C
N/C
A0
GND
ALERT
TACH
SMBDAT
SMBCLK
GPIO5
GPIO4
GPD1
GPD2
GPD3
GPD4
GPD5
Analog Input
Analog Input
Open-Drain
Digital Output
N/A
N/A
N/A
Digital Input
Ground
Open-Drain
Digital Output
Digital Input
Digital Input/
Open-Drain Output
Digital Input
Digital Input/
Open-Drain Output
Digital Input/
Open-Drain Output
Digital Input
Digital Input
Digital Input
Digital Input
Digital Input
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2
LM64
Simplified Block Diagram
20065502
Ordering Information
Part Description
LM64 24-pin LLP
LM64 24-pin LLP
LM64 Evaluation Board
With Software and Manual
Order Number
LM64CILQ-F
LM64CILQX-F
LM64EVAL
Top Mark
64CILQF
64CILQF
N/A
Transport Media
1000 Units in Tape and Reel
4500 Units in Tape and Reel
Packaged
3
www.national.com
LM64
Typical Application
20065503
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4
LM64
Absolute Maximum Ratings
2)
Supply Voltage, V
DD
Voltage on SMBDAT, SMBCLK,
ALERT, T_Crit, PWM Pins
Voltage on Other Pins
Input Current, D− Pin
Input Current at All Other Pins (Note 3)
Package Input Current (Note 3)
Package Power Dissipation
SMBDAT, ALERT, T_Crit, PWM pins
Output Sink Current
Storage Temperature
(Notes 1,
ESD Susceptibility
(Note 4)
Human Body Model
2000 V
200 V
Machine Model
SMT Soldering Information
See National Semiconductor Application Note AN-1187,
"Leadless Leadframe Package" for information on SMT
Assembly using LLP Packages. This is available at
http://www.national.com/an/AN/AN-1187.pdf.
−0.3 V to 6.0 V
−0.5 V to 6.0 V
−0.3 V to (V
DD
+ 0. 3 V)
±
1 mA
5 mA
30 mA
(Note 5)
10 mA
−65˚C to +150˚C
Operating Ratings
(Notes 1, 2)
LM64 Operating Temperature Range
Remote Diode Temperature Range
Electrical Characteristics
Supply Voltage Range (V
DD
)
0˚C
≤
T
A
≤
+85˚C
25˚C
≤
T
D
≤
+140˚C
T
MIN
≤
T
A
≤
T
MAX
+3.0 V to +3.6 V
DC Electrical Characteristics
TEMPERATURE-TO-DIGITAL CONVERTER CHARACTERISTICS
The following specifications apply for V
DD
= 3.0 VDC to
3.6 VDC, and all analog source impedance R
S
= 50
Ω
unless otherwise specified in the conditions.
Boldface limits apply for
T
A
= T
MIN
to T
MAX
;
all other limits T
A
= +25˚C.
Parameter
Temperature Error using a diode-connected
MMBT3904 transistor. T
D
is the Remote
Diode Junction Temperature.
T
D
= T
LM64
+ 16˚C
Temperature Error Using the Local Diode
Remote Diode Resolution
Local Diode Resolution
Conversion Time of All Temperatures
D− Source Voltage
(V
D+
− V
D−
) = +0.65 V; High
Current
Low Current
Fastest Setting
Conditions
T
A
= +30˚C to
+50˚C
T
A
= +0˚C to
+85˚C
T
D
= +120˚C to
+140˚C
T
D
= +25˚C to
+140˚C
Typical
(Note 7)
Limits
(Note 8)
Units
(Limits)
˚C (max)
˚C (max)
˚C (max)
Bits
˚C
Bits
˚C
34.4
315
110
20
7
ms (max)
V
µA (max)
µA (min)
µA (max)
µA (min)
±
1
±
3
±
1
11
0.125
8
1
31.25
0.7
160
13
T
A
= +25˚C to +125˚C (Note 10)
±
3
Diode Source Current
Operating Electrical Characteristics
Parameter
ALERT, T_Crit and PWM Output Saturation
Voltage
Power-On-Reset Threshold Voltage
Supply Current (Note 9)
SMBus Inactive, 16 Hz
Conversion Rate
STANDBY Mode
Conditions
ALERT, T_Crit
I
OUT
I
OUT
4 mA
6 mA
PWM
6 mA
0.4
0.55
2.4
1.8
1.1
320
2.0
V (max)
V (max)
V (min)
mA (max)
µA
Typ
(Note 7)
Limits
(Note 8)
Units
5
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