Document
LM94023 1.5V, micro SMD, Dual-Gain Analog Temperature Sensor with Class AB Output
September 10, 2008
LM94023 1.5V, micro SMD, Dual-Gain Analog Temperature Sensor with Class AB Output
General Description
The LM94023 is a precision analog output CMOS integratedcircuit temperature sensor that operates at a supply voltage as low as 1.5 Volts. Available in the very small four-bump microSMD 0.8mm x 0.8mm) the LM94023 occupies very little board area. A class-AB output structure gives the LM94023 strong output source and sink current capability for driving heavy loads, making it well suited to source the input of a sample-and-hold analog-to-digital converter with its transient load requirements, This generally means the LM94023 can be used without external components, like resistors and buffers, on the output. While operating over the wide temperature range of −50°C to +150°C, the LM94023 delivers an output voltage that is inversely porportional to measured temperature. The LM94023's low supply current makes it ideal for battery-powered systems as well as general temperature sensing applications.
A Gain Select (GS) pin sets the gain of the temperature-tovoltage output transfer function. Either of two slopes are selectable: −5.5 mV/°C (GS=0) or −8.2 mV/°C (GS=1). In the lowest gain configuration, the LM94023 can operate with a 1.5V supply while measuring temperature over the full −50°C to +150°C operating range. Tying GS high causes the transfer function to have the largest gain for maximum temperature sensitivity. The gain-select inputs can be tied directly to VDD or Ground without any pull-up or pull-down resistors, reducing component count and board area. These inputs can also be driven by logic signals allowing the system to optimize the gain during operation or system diagnostics.
Applications
■ Cell phones ■ Wireless Transceivers
■ Battery Management ■ Automotive ■ Disk Drives ■ Games ■ Appliances
Features
■ Low 1.5V operation ■ Push-pull output with 50µA source current capability ■ Two selectable gains ■ Very accurate over wide temperature range of −50°C to
+150°C
■ Low quiescent current ■ Output is short-circuit protected ■ Extremely small microSMD package ■ Footprint compatible with the industry-standard LM20
temperature sensor
Key Specifications
■ Supply Voltage ■ Supply Current ■ Output Drive ■ Temperature
Accuracy
■ Operating
Temperature
20°C to 40°C -50°C to 70°C -50°C to 90°C -50°C to 150°C
1.5V to 5.5V
5.4 μA (typ) ±50 μA ±1.5°C ±1.8°C ±2.1°C ±2.7°C
−50°C to 150°C
Connection Diagram
Typical Transfer Characteristic
micro SMD
Output Voltage vs Temperature
Top View See NS Package Number TMD04AAA
30075001
© 2008 National Semiconductor Corporation 300750
30075024
www.national.com
LM94023
Typical Application
Full-Range Celsius Temperature Sensor (−50°C to +150°C) Operating from a Single Battery Cell
Ordering Information
Order Number LM94023BITME LM94023BITMX
Temperature Accuracy
±1.5°C to ±2.7°C ±1.5°C to ±2.7°C
Pin Descriptions
Label GS
Pin Number
Type
A1 Logic Input
30075002
NS Package Number
TMD04AAA TMD04AAA
Device Marking Date Code Date Code
Transport Media 250 Units on Tape and Reel 3000 Units on Tape and Reel
Equivalent Circuit
Function
Gain Select - Input for selecting the slope of the analog output response
GND VOUT
A2 Ground B1 Analog Output
Power Supply Ground
Outputs a voltage which is inversely proportional to temperature
VDD B2 Power
Positive Supply Voltage
www.national.com
2
LM94023
Absolute Maximum Ratings (Note 1)
Supply Voltage Voltage at Output Pin
Output Current Voltage at GS Input Pin Input Current at any pin (Note 2) Storage Temperature Maximum Junction Temperature (TJMAX) ESD Susceptibility (Note 3):
Human Body Model
−0.3V to +6.0V −0.3V to (VDD + 0.3V)
±7 mA −0.3V to +6.0V
5 mA −65°C to +150°C
+150°C
2500V
Machine Model
Soldering process must comply with National's Reflow Temperature Profile specifications. Refer to www.national.com/packaging. (Note 4)
250V
Operating Ratings (Note 1)
Specified Temperature Range:
LM94023
Supply Voltage Range (VDD) Thermal Resistance (θJA) LM94023BITME, LM94023BITMX
TMIN ≤ TA ≤ TMAX −50°C ≤ TA ≤ +150°C
+1.5 V to +5.5 V
122.6°C/W
Accuracy Characteristics
These limits do not include DC load regulation. These stated accuracy limits are with reference to the values in the LM94023 Transfer Table.
Parameter
Conditions
Limits (Note 7)
Units (Limit)
Temperature Error GS=0 (Note 8)
GS=1
TA = +20°C to +40°C; VDD = 1.5V to 5.5V TA = +0°C to +70°C; VDD = 1.5V to 5.5V TA = +0°C to +90°C; VDD = 1.5V to 5.5V TA = +0°C to +120°C; VDD = 1.5V to 5.5V TA = +0°C to +150°C; VDD = 1.5V to 5.5V TA = −50°C to +0°C; VDD = 1.6V to 5.5V TA = +20°C to +40°C; VDD = 1.8V to 5.5V TA = +0°C to +70°C; VDD = 1.9V to 5.5V TA = +0°C to +90°C; VDD = 1.9V to 5.5V TA = +0°C to +120°C; VDD = 1.9V to 5.5V TA = +0°C to +150°C; VDD = 1.9V to 5.5V TA = −50°C to +0°C; VDD = 2.3V to 5.5V
±1.5 ±1.8 ±2.1 ±2.4 ±2.7 ±1.8 ±1.5 ±1.8 ±2.1 ±2.4 ±.