MIC281
Low-Cost IttyBitty Thermal Sensor
General Description Features
The MIC281 is a digital thermal sensor capable of Remote temperature measurement using embedded
measuring the temperature of a remote PN junction. It is
thermal diodes or commodity transistors
optimized for applications favoring low cost and small size.
Accurate remote sensing: 3C max., 0C to 100C
The remote junction may be an inexpensive commodity
Excellent noise rejection
transistor, e.g., 2N3906, or an embedded thermal diode
2
such as found in Intel Pentium II/III/IV CPUs, AMD
I C and SMBus 2.0-compatible serial interface
Athlon CPUs, and Xilinx Virtex FPGAs.
SMBus timeout to prevent bus lockup
The MIC281 is 100% software and hardware backward
Voltage tolerant I/Os
compatible with the MIC280 and features the same
industry-leading noise performance and small size. The Low power shutdown mode
advanced integrating A/D converter and analog front-end
Failsafe response to diode faults
reduce errors due to noise for maximum accuracy and
3.0V to 3.6V power supply range
minimum guardbanding.
Available in IttyBitty SOT23-6 package
A 2-wire SMBus 2.0-compatible serial interface is provided
for host communication. The clock and data pins are 5V-
Applications
tolerant regardless of the value of V . They will not clamp
DD
the bus lines low even if the device is powered down.
Desktop, server, and notebook computers
Superior performance, low power, and small size make the
Set-top boxes
MIC281 an excellent choice for cost-sensitive thermal
Game consoles
management applications.
Appliances
Datasheets and support documentation are available on
Micrels website at: www.micrel.com.
Typical Application
IttyBitty is a trademark of Micrel, Inc. All other trademarks are the property of their respective owners.
Micrel Inc. 2180 Fortune Drive San Jose, CA 95131 USA tel +1 (408) 944-0800 fax + 1 (408) 474-1000 Micrel, Inc. MIC281
Ordering Information
(1)
Part Number Marking Slave Address Ambient Temp. Range Package
MIC281-0YM6 TB00 1001 000x 55 to +125C SOT23-6
b
MIC281-1YM6 TB01 1001 001x 55 to +125C SOT23-6
b
MIC281-2YM6 TB02 1001 010x 55 to +125C SOT23-6
b
MIC281-3YM6 TB03 1001 011x 55 to +125C SOT23-6
b
MIC281-4YM6 TB04 1001 100x 55 to +125C SOT23-6
b
MIC281-5YM6 TB05 1001 101x 55 to +125C SOT23-6
b
MIC281-6YM6 TB06 1001 110x 55 to +125C SOT23-6
b
MIC281-7YM6 TB07 1001 111x 55 to +125C SOT23-6
b
Note:
1. Underbar (_) may not be to scale.
Pin Configuration
SOT23-6 (M6)
Top View
Pin Description
Pin Number Pin Name Pin Function
1 VDD Analog input: Power supply input to the IC.
2 GND Ground return for all IC functions.
3 T1 Analog input: Connection to remote diode junction.
4 CLK Digital input: Serial bit clock input.
5 DATA Digital input/output: Open-drain. Serial data input/output.
6 NC No connection: Must be left unconnected.
Revision 2.0
April 23, 2014 2