MIC280
Precision IttyBitty™ Thermal Supervisor
General Description
The MIC280 is a digital thermal supervisor capable of
measuring its own internal temperature and that of a
remote PN junction. The remote junction may be an
inexpensive commodity transistor—e.g., 2N3906—or an
embedded thermal diode such as those found in Intel
®
®
Pentium II/III/IV CPUs, AMD Athlon CPUs, and Xilinx
®
®
Virtex FPGAs. A 2-wire SMBus 2.0-compatible serial
interface is provided for host communication. Remote
temperature is measured with ±1°C accuracy and 9-bit to
12-bit resolution (programmable). Independent high, low,
and overtemperature thresholds are provided for each
zone.
The advanced integrating A/D converter and analog front-
end reduce errors due to noise for maximum accuracy and
minimum guardbanding. The interrupt output signals
temperature events to the host, including data-ready and
diode faults. Critical device settings can be locked to
prevent changes and ensure failsafe operation. The clock,
data, and interrupt pins are 5V-tolerant regardless of the
value of V
DD
. They will not clamp the bus lines low even if
the device is powered down. Superior accuracy, failsafe
operation, and small size make the MIC280 an excellent
choice for the most demanding thermal management
applications.
Datasheets and support documentation are available on
Micrel’s web site at:
www.micrel.com.
Features
Measures local and remote temperature
Highly accurate remote sensing: ±1°C max., 60°C to
100°C
Superior noise immunity for reduced temperature
guardbands
9-bit to 12-bit temperature resolution for remote zone
Fault queues to further reduce nuisance tripping
Programmable high, low, and overtemperature
thresholds for each zone
SMBus 2.0-compatible serial interface including device
timeout to prevent bus lockup
Voltage-tolerant I/Os
Open-drain interrupt output pin – supports SMBus Alert
Response Address protocol
Low power shutdown mode
Locking of critical functions to ensure failsafe operation
Failsafe response to diode faults
Enables ACPI-compliant thermal management
3.0V to 3.6V power supply range
Available in IttyBitty™ SOT23-6 package
Applications
Desktop, server, and notebook computers
Printers and copiers
Test and measurement equipment
Thermal supervision of Xilinx Virtex FPGAs
Wireless/RF systems
Intelligent power supplies
Datacom/telecom cards
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 •
http://www.micrel.com
May 5, 2014
Revision 2.0
Micrel, Inc.
MIC280
Ordering Information
Part Number
MIC280-0YM6
MIC280-1YM6
MIC280-2YM6
MIC280-3YM6
MIC280-4YM6
MIC280-5YM6
MIC280-6YM6
MIC280-7YM6
Note:
1. Underbar (_) may not be to scale.
Marking
TA00
TA01
TA02
TA03
TA04
TA05
TA06
TA07
Slave Address
100 1000
b
100 1001
b
100 1010
b
100 1011
b
100 1100
b
100 1101
b
100 1110
b
100 1111
b
Ambient Temp. Range
–55° to +125°C
–55° to +125°C
–55° to +125°C
–55° to +125°C
–55° to +125°C
–55° to +125°C
–55° to +125°C
–55° to +125°C
Package
SOT23-6
SOT23-6
SOT23-6
SOT23-6
SOT23-6
SOT23-6
SOT23-6
SOT23-6
Pin Configuration
SOT23-6 (M6)
(Top View)
Pin Description
Pin Number
1
2
3
4
5
6
Pin Name
VDD
GND
T1
CLK
DATA
/INT
Pin Function
Power supply input.
Ground.
Analog input. Connection to remote diode junction.
Digital input. Serial bit clock input.
Digital input/output. Open-drain. Serial data input/output.
Digital output. Open-drain. Interrupt output.
May 5, 2014
2
Revision 2.0
Micrel, Inc.
MIC280
Absolute Maximum Ratings
(2)
Power Supply Voltage (V
DD
)........................................ +3.8V
Voltage on T1 ....................................... –0.3V to V
DD
+ 0.3V
Voltage on CLK, DATA, /INT............................. –0.3V to 6V
Current into Any Pin .................................................. ±10mA
Power Dissipation, T
A
= +125°C .............................. 109mW
Storage Temperature (Ts)......................... –65°C to +150°C
(4)
ESD Ratings
Human Body Model ..................................................... 1.5kV
Machine Model ............................................................. 200V
Soldering (SOT23-6 package)
+5
Vapor Phase (60s) ........................................... 220°C /
-0
°C
+5
Infrared (15s) .................................................... 235°C /
-0
°C
Operating Ratings
(3)
Power Supply Voltage (V
DD
) ........................ +3.0V to +3.6V
Ambient Temperature Range (T
A
) ............ –55°C to +125°C
Junction Temperature .............................................. +150°C
Junction Thermal Resistance
SOT23-6 (
JA
) .................................................. 230°C/W
Electrical Characteristics
(5,
6)
V
DD
= 3.3V; T
A
= 25°C, unless noted.
Bold
values indicate –55°C ≤ T
A
≤ +125°C, 3.0V ≤ V
DD
≤ 3.6V, unless noted .
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
(3)
Power Supply
/INT, T1 open; CLK = DATA = High;
Normal mode
I
DD
Supply Current
Shutdown mode; /INT, T1 open;
Note 7
CLK = 100kHz, DATA = High
Shutdown mode; /INT, T1 open;
CLK = DATA = High
t
POR
V
POR
V
HYST
Power-on Reset Time,
Note 7
Power-on Reset Voltage
Power-on Reset Hysteresis
Voltage,
Note 7
60°C ≤ T
D
≤ 100°C
3.15V < V
DD
< 3.45V, 25°C < T
A
< 85°C
Accuracy, Remote Temperature
Notes 3, 9, 12, 13
0°C ≤ T
D
≤ 100°C
3.15V < V
DD
< 3.45V, 25°C < T
A
< 85°C
–55°C ≤ T
D
≤ 125°C
3.15V < V
DD
< 3.45V, 25°C < T
A
< 85°C
Accuracy, Local Temperature
Notes 3, 12
0°C ≤ T
A
≤ 100°C, 3.15V < V
DD
< 3.45V
–55°C ≤ T
A
≤ 125°C, 3.15V < V
DD
< 3.45V
RES[1:0]=00 (9 bits)
t
CONV
Conversion Time
Notes 3, 10
RES[1:0]=01 (10 bits)
RES[1:0]=10 (11 bits)
RES[1:0]=11 (12 bits)
V
DD
> V
POR
All registers reset to default values;
A/D conversions initiated
0.23
9
6
200
2.65
300
2.95
0.4
mA
µA
µA
µs
V
mV
Temperature-to-Digital Converter Characteristics
±0.25
±1
±2
±1
±1.5
200
330
570
1000
±1
±2
±4
±2
±2.5
240
390
670
1250
°C
°C
°C
°C
°C
ms
ms
ms
ms
May 5, 2014
3
Revision 2.0
Micrel, Inc.
MIC280
Electrical Characteristics
(5,
6)
(Continued)
V
DD
= 3.3V; T
A
= 25°C, unless noted.
Bold
values indicate –55°C ≤ T
A
≤ +125°C, 3.0V ≤ V
DD
≤ 3.6V, unless noted .
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
(3)
Remote Temperature Input, T1
I
F
Current into External Diode
Note 7
T1 forced to 1.0V, High level
Low level
7
192
12
400
µA
µA
Serial Data I/O Pin, DATA
V
OL
V
IL
V
IH
C
IN
I
LEAK
Low Output Voltage,
Note 6
Low Input Voltage
High Input Voltage
Input Capacitance
Input Current
3V ≤ V
DD
≤ 3.6V
3V ≤ V
DD
≤ 3.6V
Note 7
2.1
10
±1
I
OL
= 3mA
I
OL
= 6mA
3V ≤ V
DD
≤ 3.6V
3V ≤ V
DD
≤ 3.6V
Note 7
2.1
10
±1
0.3
0.5
0.8
5.5
V
V
V
V
pF
µA
Serial Clock Input, CLK
V
IL
V
IH
C
IN
I
LEAK
Low Input Voltage
High Input Voltage
Input Capacitance
Input Current
0.8
5.5
V
V
pF
µA
Interrupt Output, /INT
V
OL
Low Output Voltage,
Note 6
Interrupt Propagation Delay
Notes 7, 8
Interrupt Reset Propagation
Delay,
Notes 7, 11
I
OL
= 3mA
I
OL
= 6mA
From TEMPx < TLOWx or TEMPx > THIGHx
or TEMPx > CRITx to /INT < V
OL
,
R
PULLUP
= 10kΩ
From read of STATUS or A.R.A. to /INT > V
OH
R
PULLUP
= 10kΩ
0.3
0.5
[t
CONV
]
V
V
ms
t
INT
t
nINT
I
LEAK
1
±1
µs
µA
May 5, 2014
4
Revision 2.0
Micrel, Inc.
MIC280
Electrical Characteristics
(5,
6)
(Continued)
V
DD
= 3.3V; T
A
= 25°C, unless noted.
Bold
values indicate –55°C ≤ T
A
≤ +125°C, 3.0V ≤ V
DD
≤ 3.6V, unless noted .
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
(3)
Serial Interface Timing
t
1
t
2
t
3
t
4
t
5
t
TO
Notes:
2. Exceeding the absolute maximum ratings may damage the device.
3. The device is not guaranteed to function outside its operating ratings. Final test on outgoing product is performed at T
A
= 25°C.
4. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
5. Specification for packaged product only.
6. Current into the /INT or DATA pins will result in self heating of the device. Sink current should be minimized for best accuracy.
7. Guaranteed by design over the operating temperature range. Not 100% production tested.
8. t
INT
and t
CRIT
are equal to t
CONV
.
9. T
D
is the temperature of the remote diode junction. Testing is performed using a single unit of one of the transistors listed in Table 8.
10. t
CONV
= t
CONV
(local) + t
CONV
(remote). Following the acquisition of either remote or local temperature data, the limit comparisons for that zone are
performed and the device status updated. Status bits will be set and /INT driven active, if applicable.
11. The interrupt reset propagation delay is dominated by the capacitance on the bus.
12. Accuracy specification does not include quantization noise, which may be up to ±1/2 LSB.
13. Tested at 10-bit resolution.
CLK (clock) Period
Data In Setup Time to CLK High
Data Out Stable after CLK Low
Data Low Setup Time to CLK
Low
Data High Hold Time after CLK
High
Bus Timeout
Start Condition
Stop Condition
2.5
100
300
100
100
25
30
35
µs
ns
ns
ns
ns
ms
May 5, 2014
5
Revision 2.0
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