Microchip Technology TC74A7-5.0VCT, TC74A7-5.0VAT, TC74A7-3.3VCT, TC74A7-3.3VAT, TC74A6-5.0VCT Datasheet
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Tiny Serial Digital Thermal Sensor
TC74
Features
• Digital TemperatureSensing in SOT-23-5 Package
• Outputs Temperature as an8-Bit Digital Word
• Simple Serial Port Interface
• Solid-State Temperature Sensing:
- ±2°C Accuracy from +25°C to +85°C
- ±3°C Accuracy from 0°C to +125°C
• 3.0 and 5.5V Operating Range
•LowPower:
- 200µA Operating
-5µA Standby Mode
Applications
• Thermal Protection for Hard Disk Drives
and other PC Peripherals
• PC Card Devices for Notebook Computers
• Low Cost Thermostat Controls
• Power Supplies
• Thermistor Replacement
Package Type
TO-220
General Description
The TC74 is a serially accessible digital temperature
sensor particularly suited for low cost and small formfactorapplications. Temperaturedataisconverted from
the onboard thermal sensing element and made
available as an 8-bit digital word.
Communicationwiththe TC74 is accomplishedviaa 2wire SMBus/I
can be used to implement multi-drop/multi-zone
monitoring. The SHDN bit in the CONFIG register can
be used to activate the low power Standby mode.
Temperature resolution is 1°C. Conversion rate is a
nominal 8 samples/sec. Power consumption is only
200µAtyp,(5µA Standby, typ).
Smallsize,lowinstalledcost,andeaseofusemakethe
TC74 an ideal choice for implementing thermal
management in a variety of systems.
2C™
compatible serial port. This bus also
Functional Block Diagram
Internal Sensor
(Diode)
Serial Port
Interface
SDA
SCL
TC74
12345
SDA
GND
DD
V
SCLK
NC
SOT-23
SDA SCLK
5
4
TC74
NC
1
2
GND
3
V
DD
∆∑ Modulator
Control
Logic
Temperature
Register
2002 Microchip TechnologyInc. DS21462B-page 1
TC74
Device Selection Table
Part Number Package Address Temperature Range
TC74A0-3.3VCT SOT-23A-5 1001 000 -40°C to +125°C
TC74A1-3.3VCT SOT-23A-5 1001 001 -40°C to +125°C
TC74A2-3.3VCT SOT-23A-5 1001 010 -40°C to +125°C
TC74A3-3.3VCT SOT-23A-5 1001 011 -40°C to +125°C
TC74A4-3.3VCT SOT-23A-5 1001 100 -40°C to +125°C
TC74A5-3.3VCT* SOT-23A-5 1001 101* -40°C to +125°c
TC74A6-3.3VCT SOT-23A-5 1001 110 -40°C to +125°C
TC74A7-3.3VCT SOT-23A-5 1001 111 -40°C to +125°C
TC74A0-5.0VCT SOT-23A-5 1001 000 -40°C to +125°C
TC74A1-5.0VCT SOT-23A-5 1001 001 -40°C to +125°C
TC74A2-5.0VCT SOT-23A-5 1001 010 -40°C to +125°C
TC74A3-5.0VCT SOT-23A-5 1001 011 -40°C to +125°C
TC74A4-5.0VCT SOT-23A-5 1001 100 -40°C to +125°C
TC74A5-5.0VCT* SOT-23A-5 1001 101 -40°C to +125°C
TC74A6-5.0VCT SOT-23A-5 1001 110 -40°C to +125°C
TC74A7-5.0VCT SOT-23A-5 1001 111 -40°C to +125°C
TC74A0-3.3VAT TO-220-5 1001 000 -40°C to +125°C
TC74A1-3.3VAT TO-220-5 1001 001 -40°C to +125°C
TC74A2-3.3VAT TO-220-5 1001 010 -40°C to +125°C
TC74A3-3.3VAT TO-220-5 1001 011 -40°C to +125°C
TC74A4-3.3VAT TO-220-5 1001 100 -40°C to +125°C
TC74A5-3.3VAT TO-220-5 1001 101 -40°C to +125°C
TC74A6-3.3VAT TO-220-5 1001 110 -40°C to +125°C
TC74A7-3.3VAT TO-220-5 1001 111 -40°C to +125°C
TC74A0-5.0VAT TO-220-5 1001 000 -40°C to +125°C
TC74A1-5.0VAT TO-220-5 1001 001 -40°C to +125°C
TC74A2-5.0VAT TO-220-5 1001 010 -40°C to +125°C
TC74A3-5.0VAT TO-220-5 1001 011 -40°C to +125°C
TC74A4-5.0VAT TO-220-5 1001 100 -40°C to +125°C
TC74A5-5.0VAT TO-220-5 1001 101 -40°C to +125°C
TC74A6-5.0VAT TO-220-5 1001 110 -40°C to +125°C
TC74A7-5.0VAT TO-220-5 1001 111 -40°C to +125°C
NOTE: *DefaultAddress.
DS21462B-page 2
2002 Microchip TechnologyInc.
TC74
1.0 ELECTRICAL
CHARACTERISTICS
*Stresses above those listed under "Absolute Maximum Ratings"maycause permanentdamage to thedevice.These are
stress ratings only and functional operation of the device at
these or any other conditions above those indicated in the
Absolute Maximum Ratings*
Supply Voltage (VDD)............................................ +6V
Voltage On Any Pin....... (GND – 0.3V) to (V
DD
+0.3V)
operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended
periodsmay affectdevice reliability.
Current On Any Pin.......................................... ±50 mA
Operating Temperature (T
StorageTemperature (T
)........................ See Below
A
)..............-65°C to +150°C
STG
TC74 ELECTRICAL SPECIFICATIONS
Electrical Characteristics: VDD=3.3Vor5.0V(Note 5),-40°C≤ TA≤ 125°C, unless otherwisenoted.
Symbol Parameter Min Typ. Max Unit Test Conditions
Power Supply
V
POR
I
DD
I
DD-STANDBY
Temperature to Bits Converter
T
ERR
CR Conversion Rate 4 8 — Sps (Note2)
Serial Port Interface
V
IH
V
IL
V
OL
C
IN
I
LEAK
Note 1: Operating current is an average value integrated over multiple conversion cycles. Transient current may exceed this specification.
2: Maximum ensured conversion time after Power-on Reset (POR to DATA_RDY) is 250 msec.
3: Output current should be minimized for best temperature accuracy. Power dissipation within the TC74 will cause self-heating and
4: SDA andSCLK mustbe connectedto V
5: V
Power-on Reset Threshold 1.2 — 2.2 V VDDFalling Edge or Rising Edge
Operating Current — 200 350 µAVDD=5.5V
Serial Port Inactive (Note 1)
StandbySupply Current — 5 10 µAVDD=3.3V
Serial Port Inactive (Note 1)
DD
°C +25°C<T
0°C < T
-40°C < T
V
V
IOL=3mA
V
I
=6mA(Note 3)
OL
<+85°C
A
< +125°C
A
<0°C
A
Temperature Accuracy TC74A -2
-3
—
Logic Input High 0.8 x V
—+2
—
+2
—— V
DD
Logic Input Low — — 0.2 x V
SDA OutputLow —
—
—
—
0.4
0.6
Input Capacitance SDA, SCL — 5 — pF
I/O Leakage -1 0.1 1 µA
temperature drift error.
or GND.
= 3.3V for TC74X -3.3VCT. VDD= 5.0V for TC74X -5.0VCT. All part types of the TC74 will operate properly over the wider power
DD
supply range of 2.7V to 5.5V. Each part type is tested and specified for rated accuracy at its nominal supply voltage. As V
the nominal value, accuracy will degrade 1°C/V of V
DD
DD
change.
DD
varies from
2002 Microchip TechnologyInc. DS21462B-page 3
TC74
TC74 ELECTRICAL SPECIFICATIONS (CONTINUED)
Electrical Characteristics: VDD=3.3Vor5.0V(Note 5),-40°C≤ TA≤ 125°C, CL= 80pF unless otherwise noted.
Serial Port AC Timing
Symbol Parameter Min Typ. Max Unit Test Conditions
f
SMB
t
LOW
t
HIGH
t
R
t
F
t
SU(START)
t
H(START)
t
SU-DATA
t
H-DATA
t
SU(STOP)
t
IDLE
t
POR
Note 1: Operating current is an average value integrated over multiple conversion cycles. Transient current may exceed this specification.
2: Maximum ensured conversion time after Power-on Reset (POR to DATA_RDY) is 250 msec.
3: Output current should be minimized for best temperature accuracy. Power dissipation within the TC74 will cause self-heating and
4: SDA andSCLK mustbe connectedto V
5: V
SMBusClockFrequency 10 — 100 kHz
Low Clock Period 4.7 — — µsec 10% to 10%
High Clock Period 4 — — µsec 90% to 90%
SMBusRiseTime
SMBus Fall Time
STAR T Condition Setup Time
—
—
—
1000
—
300
nsec
nsec
10% to 90%
90% to10%
4——µsec 90% SCLK to 10% SDA
(forrepeated START Condition)
START Condition Hold Time 4 — — µsec
Data In Setup Time 1000 — — nsec
Data In Hold Time 1250 — — nsec
STOP Condition Setup Time 4 — — µsec
Bus Free Time Prior to New Tran-
4.7 — — µsec
sition
Power-on Res et Delay — 500 — µsec VDD≥ V
temperature drift error.
or GND.
= 3.3V for TC74X -3.3VCT. VDD= 5.0V for TC74X -5.0VCT. All part types of the TC74 will operate properly over the wider power
DD
supply range of 2.7V to 5.5V. Each part type is tested and specified for rated accuracy at its nominal supply voltage. As V
the nominal value, accuracy will degrade 1°C/V of V
DD
DD
change.
(Rising Edge)
POR
DD
varies from
DS21462B-page 4
2002 Microchip TechnologyInc.
2.0 PIN DESCRIPTIONS
ThedescriptionsofthepinsarelistedinTable2-1.
TABLE 2-1: PIN FUNCTION TABLE
TC74
Pin Number
(5-Pin SOT-23)
1 1 NC None No Internal Connection.
2 3 GND Power System Ground
35V
4 4 SCLK Input SMBus Serial Clock
5 2 SDA Bi-directional SMBus Serial Data
Pin Number
(5-Pin TO-220)
Symbol Type Description
DD
Power Power Supply Input
2002 Microchip TechnologyInc. DS21462B-page 5
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