2010 Microchip Technology Inc.
DS21935D-page 1
TCN75A
Features:
• Temperature-to-Digital Converter
• Accuracy:
- ±1 (typical) from -40°C to +125°C
- ±2°C (maximum) from -40°C to +125°C
• User-selectable Resolution: 0.5°C to 0.0625°C
• Operating Voltage Range: 2.7V to 5.5V
• 2-wire Interface: I
2
C™ Compatible
• Operating Current: 200 µA (typical)
• Shutdown Current: 2 µA (maximum)
• Power-saving One-shot Temperature
Measurement
• Available Packages: MSOP-8, SOIC-8
Typical Applications:
• Personal Computers and Servers
• Hard Disk Drives and Other PC Peripherals
• Entertainment Systems
• Office Equipment
• Data Communication Equipment
• General Purpose Temperature Monitoring
Typical Application
Description:
Microchip Technology Inc.’s TCN75A digital tempera-
ture sensor converts temperatures between -40°C and
+125°C to a digital word, with ±1°C (typical) accuracy.
The TCN75A product comes with user-programmable
registers that provide flexibility for temperature-sensing
applications. The register settings allow
user-selectable, 0.5°C to 0.0625°C temperature
measurement resolution, configuration of the
power-saving Shutdown and One-shot (single
conversion on command while in Shutdown) modes
and the specification of both temperature alert output
and hysteresis limits. When the temperature changes
beyond the specified limits, the TCN75A outputs an
alert signal. The user has the option of setting the alert
output signal polarity as an active-low or active-high
comparator output for thermostat operation, or as
temperature event interrupt output for
microprocessor-based systems.
This sensor has an industry standard 2-wire, I
2
C™
compatible serial interface, allowing up to eight devices
to be controlled in a single serial bus. These features
make the TCN75A ideal for low-cost, sophisticated
multi-zone temperature-monitoring applications.
Package Types
V
DD
R
TCN75A
SDA
SCL
I/O Ports
R
PULL-UP
PIC
®
1
2
3
4
8
7
6
5
A0
V
DD
A1
A2
SDA
GND
ALERT
SCL
Microcontroller
ALERT
V
DD
SDA
GND
ALERT
SCL
1
2
3
4
8
7
6
5
8-Pin SOIC, MSOP
A0
V
DD
A1
A2
TCN7
5
A
2-Wire Serial Temperature Sensor
TCN75A
DS21935D-page 2
2010 Microchip Technology Inc.
NOTES:
2010 Microchip Technology Inc.
DS21935D-page 3
TCN75A
1.0
ELECTRICAL
CHARACTERISTICS
Absolute Maximum Ratings †
V
DD
....................................................................... 6.0V
Voltage at all Input/Output pins .....GND – 0.3V to 5.5V
Storage temperature .......................... -65°C to +150°C
Ambient temp. with power applied ..... -55°C to +125°C
Junction Temperature (T
J
) ................................. 150°C
ESD protection on all pins (HBM:MM) .......(4 kV:400V)
Latch-up current at each pin ......................... ±200 mA
†Notice:
Stresses above those listed under “Maximum
ratings” may cause permanent damage to the device. This is
a stress rating only and functional operation of the device at
those or any other conditions above those indicated in the
operational listings of this specification is not implied.
Exposure to maximum rating conditions for extended periods
may affect device reliability.
DC CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 2.7V to 5.5V, GND = Ground, and
T
A
= -40°C to +125°C.
Parameters
Sym
Min
Typ
Max
Unit
Conditions
Power Supply
Operating Voltage Range
V
DD
2.7
—
5.5
V
Operating Current
I
DD
—
200
500
µA
Continuous operation
Shutdown Current
I
SHDN
—
0.1
2
µA
Shutdown mode
Power-on Reset (POR) Threshold
V
POR
—
1.7
—
V
V
DD
falling edge
Line Regulation
°C/V
DD
—
0.2
—
°C/V
V
DD
= 2.7V to 5.5V
Temperature Sensor Accuracy
T
A
= -40°C to +125°C
T
ACY
-2
±1
+2
°C
V
DD
= 3.3V
Internal
ADC
Conversion Time:
0.5°C Resolution
t
CONV
—
30
—
ms
33 samples/sec (typical)
0.25°C Resolution
t
CONV
—
60
—
ms
17 samples/sec (typical)
0.125°C Resolution
t
CONV
—
120
—
ms
8 samples/sec (typical)
0.0625°C Resolution
t
CONV
—
240
—
ms
4 samples/sec (typical)
Alert Output (Open-drain)
High-level Current
I
OH
—
—
1
µA
V
OH
= 5V
Low-level Voltage
V
OL
—
—
0.4
V
I
OL
= 3 mA
Thermal Response
Response Time
t
RES
—
1.4
—
s
Time to 63% (89°C)
27°C (air) to 125°C (oil
bath)
TCN75A
DS21935D-page 4
2010 Microchip Technology Inc.
Graphical Symbol Description
DIGITAL INPUT/OUTPUT PIN CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= 2.7V to 5.5V, GND = Ground and
T
A
= -40°C to +125°C.
Parameters
Sym
Min
Typ
Max
Units
Conditions
Serial Input/Output (SCL, SDA, A0, A1, A2)
Input
High-level Voltage
V
IH
0.7 V
DD
—
—
V
Low-level Voltage
V
IL
—
—
0.3 V
DD
V
Input Current
I
IN
-1
—
+1
µA
Output (SDA)
Low-level Voltage
V
OL
—
—
0.4
V
I
OL
= 3 mA
High-level Current
I
OH
—
—
1
µA
V
OH
= 5V
Low-level Current
I
OL
6
—
—
mA
V
OL
= 0.6V
Capacitance
C
IN
—
10
—
pF
SDA and SCL Inputs
Hysteresis
V
HYST
0.05 V
DD
—
—
V
V
DD
V
IH
V
IL
I
IN
Voltage
Current
time
time
V
DD
I
OH
Voltage
Current
time
time
INPUT
OUTPUT
V
OL
I
OL
TEMPERATURE CHARACTERISTICS
Electrical Specifications:
Unless otherwise indicated, V
DD
= +2.7V to +5.5V and GND = Ground.
Parameters
Sym
Min
Typ
Max
Units
Conditions
Temperature Ranges
Specified Temperature Range
T
A
-40
—
+125
°C
Note 1
Operating Temperature Range
T
A
-40
—
+125
°C
Storage Temperature Range
T
A
-65
—
+150
°C
Thermal Package Resistances
Thermal Resistance, 8L-SOIC
JA
—
163
—
°C/W
Thermal Resistance, 8L-MSOP
JA
—
206
—
°C/W
Note 1:
Operation in this range must not cause T
J
to exceed Maximum Junction Temperature (+150°C).
2010 Microchip Technology Inc.
DS21935D-page 5
TCN75A
Timing Diagram
SERIAL INTERFACE TIMING SPECIFICATIONS (
Note 1
)
Electrical Specifications:
Unless otherwise indicated, V
DD
= 2.7V to 5.5V, GND = Ground, T
A
= -40°C to +125°C,
C
L
= 80 pF and all limits measured to 50% point.
Parameters
Sym
Min
Typ
Max
Units
Conditions
2-Wire I
2
C™ Compatible Interface
Serial Port Frequency
f
SC
0
—
400
kHz
Clock Period
t
SC
2.5
—
—
µs
Low Clock
t
LOW
1.3
—
—
µs
High Clock
t
HIGH
0.6
—
—
µs
Rise Time
t
R
20
—
300
ns
10% to 90% of V
DD
(SCL, SDA)
Fall Time
t
F
20
—
300
ns
90% to 10% of V
DD
(SCL, SDA)
Data Setup Before SCL High
t
SU-DATA
0.1
—
—
µs
Data Hold After SCL Low
t
H-DATA
0
—
—
µs
Start Condition Setup Time
t
SU-START
0.6
—
—
µs
Start Condition Hold Time
t
H-START
0.6
—
—
µs
Stop Condition Setup Time
t
SU-STOP
0.6
—
—
µs
Bus Idle
t
B-FREE
1.3
—
—
µs
Note 1:
Specification limits are characterized but not product tested.
t
SU
-S
TA
RT
t
H-S
TA
RT
t
SU
-D
ATA
t
SU
-S
TO
P
t
B-
FR
EE
SCL
SDA
t
H-
DA
TA
t
HI
GH
t
LOW
t
R
, t
F
Start Condition
Data Transmission
Stop Condition
TCN75A
DS21935D-page 6
2010 Microchip Technology Inc.
NOTES:
2010 Microchip Technology Inc.
DS21935D-page 7
TCN75A
2.0
TYPICAL PERFORMANCE CURVES
Note:
Unless otherwise noted: V
DD
= 2.7V to 5.5V.
FIGURE 2-1:
Average Temperature
Accuracy vs. Ambient Temperature, V
DD
= 3.3V.
FIGURE 2-2:
Average Temperature
Accuracy vs. Ambient Temperature.
FIGURE 2-3:
Average Temperature
Accuracy vs. Ambient Temperature, V
DD
= 3.3V.
FIGURE 2-4:
Temperature Accuracy
Histogram, T
A
= +25°C.
FIGURE 2-5:
Supply Current vs. Ambient
Temperature.
FIGURE 2-6:
Shutdown Current vs.
Ambient Temperature.
Note:
The graphs and tables provided following this note are a statistical summary based on a limited number of
samples and are provided for informational purposes only. The performance characteristics listed herein
are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified
operating range (e.g., outside specified power supply range) and therefore outside the warranted range.
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
Tem
p
e
ra
tur
e A
c
cur
a
cy (°C
)
0.0625°C Resolution
160 Devices
V
DD
= 3.3V
Specification
Limits
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
Temper
atur
e A
ccur
acy (°C
)
0.0625°C Resolution
160 Devices
V
DD
= 2.7V
V
DD
= 3.3V
V
DD
= 5.5V
V
DD
= 5.0V
-3.0
-2.0
-1.0
0.0
1.0
2.0
3.0
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
Temper
atur
e A
ccur
acy (°C
)
0.125°C
0.0625°C
0.5°C
0.25°C
V
DD
= 3.3V
160 Devices
Resolution
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
-3
.0
-2
.5
-2
.0
-1
.5
-1
.0
-0
.5
0.0
0.5
1.0
1.5
2.0
2.5
3.0
Temperature Accuracy (°C)
Oc
cu
rr
enc
e
s
T
A
= +25°C
V
DD
= 3.3V
5 lots
32 Samples/lot
160 Devices
50
100
150
200
250
300
350
400
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
I
DD
(µA
)
V
DD
= 2.7V
V
DD
= 3.3V
V
DD
= 5.5V
V
DD
= 5.0V
0
0.2
0.4
0.6
0.8
1
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C )
I
SH
DN
(µ
A
)
TCN75A
DS21935D-page 8
2010 Microchip Technology Inc.
Note:
Unless otherwise noted: V
DD
= 2.7V to 5.5V.
FIGURE 2-7:
ALERT and SDA I
OL
vs.
Ambient Temperature.
FIGURE 2-8:
ALERT and SDA Output
V
OL
vs. Ambient Temperature.
FIGURE 2-9:
TCN75A Thermal Response
vs. Time.
6
12
18
24
30
36
42
48
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
AL
E
R
T
a
n
d
S
DA I
OL
(m
A
)
V
DD
= 5.5V
V
DD
= 3.3V
V
DD
= 2.7V
V
OL
= 0.6V
0
0.1
0.2
0.3
0.4
-55
-35
-15
5
25
45
65
85
105 125
T
A
(°C)
AL
ER
T a
n
d
SD
A
V
OL
(V
)
V
DD
= 5.5V
V
DD
= 3.3V
V
DD
= 2.7V
I
OL
= 3 mA
5
25
45
65
85
105
125
145
-2
0
2
4
6
8
10
12
14
16
18
20
Time (s)
T
e
m
p
er
at
u
re D
a
ta
(
°C
)
SOIC
Average of 10 samples per package
27°C (Air) to 125°C (Oil bath)
MSOP
2010 Microchip Technology Inc.
DS21935D-page 9
TCN75A
3.0
PIN DESCRIPTION
The descriptions of the pins are listed in
Table 3-1
.
TABLE 3-1:
PIN FUNCTION TABLE
3.1
Serial Data Pin (SDA)
SDA is a bidirectional input/output pin, used to serially
transmit data to and from the host controller. This pin
requires a pull-up resistor to output data.
3.2
Serial Clock Pin (SCL)
SCL is a clock input pin. All communication and timing
is relative to the signal on this pin. The clock is
generated by the host controller on the bus.
3.3
Power Supply Input (V
DD
)
V
DD
is the power pin. The operating voltage, as
specified in the DC electrical specification table, is
applied on this pin.
3.4
Ground (GND)
GND is the system ground pin.
3.5
ALERT Output
The TCN75A’s ALERT pin is an open-drain output. The
device outputs an alert signal when the ambient
temperature goes beyond the user-programmed
temperature limit.
3.6
Address Pins (A2, A1, A0)
A2, A1 and A0 are device or slave address input pins.
The address pins are the Least Significant bits (LSb) of
the device address bits. The Most Significant bits
(MSb) (A6, A5, A4, A3) are factory-set to <1001>. This
is illustrated in
Table 3-2
.
MSOP, SOIC
Symbol
Function
1
SDA
Bidirectional Serial Data
2
SCL
Serial Clock Input
3
ALERT
Temperature Alert Output
4
GND
Ground
5
A2
Address Select Pin (bit 2)
6
A1
Address Select Pin (bit 1)
7
A0
Address Select Pin (bit 0)
8
V
DD
Power Supply Input
TABLE 3-2:
SLAVE ADDRESS
Device
A6
A5
A4
A3
A2
A1
A0
TCN75A
1
0
0
1
X
X
X
Note:
User-selectable address is shown by X.
TCN75A
DS21935D-page 10
2010 Microchip Technology Inc.
NOTES: