Texas Instruments TMP421, TMP422, TMP423A, TMP423B Schematic [ru]

	TMP421
	TMP422
www.ti.com	TMP423

SBOS398B–JULY 2007–REVISED MARCH 2008

±1°C Remote and Local TEMPERATURE SENSOR

in SOT23-8

FEATURES

∙SOT23-8 PACKAGE

∙±1°C REMOTE DIODE SENSOR (MAX)

∙±1.5°C LOCAL TEMPERATURE SENSOR (MAX)

∙SERIES RESISTANCE CANCELLATION

∙n-FACTOR CORRECTION

∙TWO-WIRE/SMBus™ SERIAL INTERFACE

∙MULTIPLE INTERFACE ADDRESSES

∙DIODE FAULT DETECTION

∙RoHS COMPLIANT AND NO Sb/Br

APPLICATIONS

∙PROCESSOR/FPGA TEMPERATURE MONITORING

∙LCD/DLP®/LCOS PROJECTORS

∙SERVERS

∙CENTRAL OFFICE TELECOM EQUIPMENT

∙STORAGE AREA NETWORKS (SAN)

DESCRIPTION

The TMP421, TMP422, and TMP423 are remote temperature sensor monitors with a built-in local temperature sensor. The remote temperature sensor diode-connected transistors are typically low-cost, NPNor PNP-type transistors or diodes that are an integral part of microcontrollers, microprocessors, or FPGAs.

Remote accuracy is ±1°C for multiple IC manufacturers, with no calibration needed. The two-wire serial interface accepts SMBus write byte, read byte, send byte, and receive byte commands to configure the device.

The TMP421, TMP422, and TMP423 include series resistance cancellation, programmable non-ideality factor, wide remote temperature measurement range (up to +150°C), and diode fault detection.

The TMP421, TMP422, and TMP423 are all available in a SOT23-8 package.

+5V

TMP421	TMP422	TMP423
			8
1 DXP	1 DX1	1 DXP1	V+	7
			SCL
				SMBus
2	2	2		Controller
			SDA	6
DXN	DX2	DXP2
3
A1	3	3
	DX3	DXP3
4	4	4
A0
	DX4	DXN
			GND
			5
1 Channel Local	1 Channel Local	1 Channel Local
1 Channel Remote	2 Channels Remote	3 Channels Remote

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

DLP is a registered trademark of Texas Instruments. SMBus is a trademark of Intel Corporation.

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.	Copyright © 2007–2008, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.

TMP421

TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.

PACKAGE INFORMATION(1)

		TWO-WIRE		PACKAGE	PACKAGE
PRODUCT	DESCRIPTION	ADDRESS	PACKAGE-LEAD	DESIGNATOR	MARKING
	Single Channel
TMP421	Remote Junction	100 11xx	SOT23-8	DCN	DACI
	Temperature Sensor
	Dual Channel
TMP422	Remote Junction	100 11xx	SOT23-8	DCN	DADI
	Temperature Sensor
TMP423A	Triple Channel	100 1100	SOT23-8	DCN	DAEI
TMP423B	Remote Junction	100 1101	SOT23-8	DCN	DAFI
	Temperature Sensor

(1)For the most current package and ordering information see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com.

ABSOLUTE MAXIMUM RATINGS(1)

Over operating free-air temperature range, unless otherwise noted.

			TMP421, TMP422, TMP423	UNIT
	Power Supply, VS		+7	V
	Input Voltage	Pins 1, 2, 3, and 4 only	–0.5 to VS + 0.5	V
		Pins 6 and 7 only	–0.5 to 7	V
	Input Current		10	mA
	Operating Temperature Range		–55 to +127	°C
	Storage Temperature Range		–60 to +130	°C
	Junction Temperature (TJ max)		+150	°C
		Human Body Model (HBM)	3000	V
	ESD Rating	Charged Device Model (CDM)	1000	V
		Machine Model (MM)	200	V

(1)Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not implied.

2

Submit Documentation Feedback

Copyright © 2007–2008, Texas Instruments Incorporated

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421 TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

ELECTRICAL CHARACTERISTICS

At TA = –40°C to +125°C and VS = 2.7V to 5.5V, unless otherwise noted.

			TMP421, TMP422, TMP423
PARAMETER		CONDITIONS	MIN	TYP	MAX	UNIT
TEMPERATURE ERROR
Local Temperature Sensor	TELOCAL	TA = –40°C to +125°C		±1.25	±2.5	°C
		TA = +15°C to +85°C, VS = 3.3V		±0.25	±1.5	°C
Remote Temperature Sensor(1)	TEREMOTE	TA = +15°C to +85°C, TD = –40°C to +150°C, VS = 3.3V		±0.25	±1	°C
		TA = –40°C to +100°C, TD = –40°C to +150°C, VS = 3.3V		±1	±3	°C
		TA = –40°C to +125°C, TD = –40°C to +150°C		±3	±5	°C
vs Supply (Local/Remote)		VS = 2.7V to 5.5V		±0.2	±0.5	°C/V
TEMPERATURE MEASUREMENT
Conversion Time (per channel)			100	115	130	ms
Resolution
Local Temperature Sensor (programmable)				12		Bits
Remote Temperature Sensor				12		Bits
Remote Sensor Source Currents
High		Series Resistance 3kΩ Max		120		μA
Medium High				60		μA
Medium Low				12		μA
Low				6		μA
Remote Transistor Ideality Factor	η	TMP421/22/23 Optimized Ideality Factor		1.008
SMBus INTERFACE
Logic Input High Voltage (SCL, SDA)	VIH		2.1			V
Logic Input Low Voltage (SCL, SDA)	VIL				0.8	V
Hysteresis				500		mV
SMBus Output Low Sink Current			6			mA
SDA Output Low Voltage	VOL	IOUT = 6mA		0.15	0.4	V
Logic Input Current		0 ≤ VIN ≤ 6V	–1		+1	μA
SMBus Input Capacitance (SCL, SDA)				3		pF
SMBus Clock Frequency					3.4	MHz
SMBus Timeout			25	30	35	ms
SCL Falling Edge to SDA Valid Time					1	μs
DIGITAL INPUTS
Input Capacitance				3		pF
Input Logic Levels
Input High Voltage	VIH		0.7(V+)		(V+)+0.5	V
Input Low Voltage	VIL		–0.5		0.3(V+)	V
Leakage Input Current	IIN	0V ≤ VIN ≤ VS			1	μA
POWER SUPPLY
Specified Voltage Range	VS		2.7		5.5	V
Quiescent Current	IQ	0.0625 Conversions per Second		32	38	μA
		Eight Conversions per Second		400	525	μA
		Serial Bus Inactive, Shutdown Mode		3	10	μA
		Serial Bus Active, fS = 400kHz, Shutdown Mode		90		μA
		Serial Bus Active, fS = 3.4MHz, Shutdown Mode		350		μA
Undervoltage Lockout	UVLO		2.3	2.4	2.6	V
Power-On Reset Threshold	POR			1.6	2.3	V
TEMPERATURE RANGE
Specified Range			–40		+125	°C
Storage Range			–60		+130	°C
Thermal Resistance, SOT23	θJA			100		°C/W

(1)Tested with less than 5Ω effective series resistance and 100pF differential input capacitance.

Copyright © 2007–2008, Texas Instruments Incorporated

Submit Documentation Feedback

3

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421

TMP422

TMP423									www.ti.com
SBOS398B–JULY 2007–REVISED MARCH 2008
		TMP421 PIN CONFIGURATION
					DCN PACKAGE
					SOT23-8
					(TOP VIEW)
									V+
		DXP		1				8
									SCL
		DXN		2				7
					TMP421
		A1		3				6	SDA
		A0							GND
				4				5
		TMP421 PIN ASSIGNMENTS
	TMP421
NO.	NAME	DESCRIPTION
1	DXP	Positive connection to remote temperature sensor.
2	DXN	Negative connection to remote temperature sensor.
3	A1	Address pin
4	A0	Address pin
5	GND	Ground
6	SDA	Serial data line for SMBus, open-drain; requires pull-up resistor to V+.
7	SCL	Serial clock line for SMBus, open-drain; requires pull-up resistor to V+.
8	V+	Positive supply voltage (2.7V to 5.5V)
		TMP422 PIN CONFIGURATION
					DCN PACKAGE
					SOT23-8
					(TOP VIEW)
									V+
		DX1		1				8
									SCL
		DX2		2				7
					TMP422
		DX3		3				6	SDA
									GND
		DX4		4				5
		TMP422 PIN ASSIGNMENTS
	TMP422
NO.	NAME	DESCRIPTION
1	DX1	Channel 1 remote temperature sensor connection pin. Also sets the TMP422 address; see Table 10.
2	DX2	Channel 1 remote temperature sensor connection pin. Also sets the TMP422 address; see Table 10.
3	DX3	Channel 2 remote temperature sensor connection pin. Also sets the TMP422 address; see Table 10.
4	DX4	Channel 2 remote temperature sensor connection pin. Also sets the TMP422 address; see Table 10.
5	GND	Ground
6	SDA	Serial data line for SMBus, open-drain; requires pull-up resistor to V+.
7	SCL	Serial clock line for SMBus, open-drain; requires pull-up resistor to V+.
8	V+	Positive supply voltage (2.7V to 5.5V)

4

Submit Documentation Feedback

Copyright © 2007–2008, Texas Instruments Incorporated

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421 TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

TMP423 PIN CONFIGURATION

DCN PACKAGE

SOT23-8

(TOP VIEW)

				V+
DXP1	1		8
				SCL
DXP2	2		7
		TMP423
DXP3	3		6	SDA
DXN				GND
	4		5

		TMP423 PIN ASSIGNMENTS
	TMP423
NO.	NAME	DESCRIPTION
1	DXP1	Channel 1 positive connection to remote temperature sensor.
2	DXP2	Channel 2 positive connection to remote temperature sensor.
3	DXP3	Channel 3 positive connection to remote temperature sensor.
4	DXN	Common negative connection to remote temperature sensors, Channel 1, Channel 2, Channel 3.
5	GND	Ground
6	SDA	Serial data line for SMBus, open-drain; requires pull-up resistor to V+.
7	SCL	Serial clock line for SMBus, open-drain; requires pull-up resistor to V+.
8	V+	Positive supply voltage (2.7V to 5.5V)

Copyright © 2007–2008, Texas Instruments Incorporated

Submit Documentation Feedback

5

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421

TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

TYPICAL CHARACTERISTICS

At TA = +25°C and VS = +5.0V, unless otherwise noted.

RemoteTemperatureError(°C)

REMOTE TEMPERATURE ERROR	LOCAL TEMPERATURE ERROR
vs TEMPERATURE	vs TEMPERATURE

3	VS	= 3.3V							3
										VS = 3.3V				50 Units Shown
	TREMOTE = +25°C
2								°C)	2
	30 Typical Units Shown
	η = 1.008							(
								Error
1									1
−2								LocalTemperature	−2
0									0
−1									−1
−3									−3
	−50	−25	0	25	50	75	100	125	−50	−25	0	25	50	75	100	125
			Ambient Temperature, TA (°C)								Ambient Temperature, TA (°C)

Figure 1.

REMOTE TEMPERATURE ERROR vs LEAKAGE RESISTANCE

°C)	60
	40
(
emperatureErrorRemoteT	20
								R −GND
	0
									R −VS
	−20
	−40
	−60
	0		5		10		15		20		25		30

Leakage Resistance (MΩ )

Figure 3.

REMOTE TEMPERATURE ERROR vs SERIES RESISTANCE (GND Collector-Connected Transistor, 2N3906 PNP)

	2.0
°C)	1.5
					VS = 2.7V
(
RemoteTemperatureError	1.0
	0.5
	0						VS = 5.5V
	−0.5
	−1.0
	−1.5
	−2.0
	0	500	1000	1500	2000	2500	3000	3500
				RS ( Ω )

Figure 5.

Figure 2.

REMOTE TEMPERATURE ERROR vs SERIES RESISTANCE (Diode-Connected Transistor, 2N3906 PNP)

	2.0
°C)	1.5
					VS = 2.7V
(
RemoteTemperatureError	1.0
	0.5
	0
							VS = 5.5V
	−0.5
	−1.0
	−1.5
	−2.0
	0	500	1000	1500	2000	2500	3000	3500
				RS ( Ω )

Figure 4.

REMOTE TEMPERATURE ERROR vs DIFFERENTIAL CAPACITANCE

	3
°C)	2
(
emperatureErrorRemoteT	1
	0
	−1
	−2
	−3

0

0.5

1.0

1.5

2.0

2.5

3.0

Capacitance (nF)

Figure 6.

6

Submit Documentation Feedback

Copyright © 2007–2008, Texas Instruments Incorporated

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421 TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

TYPICAL CHARACTERISTICS (continued)

At TA = +25°C and VS = +5.0V, unless otherwise noted.

		TEMPERATURE ERROR
		vs POWER-SUPPLY NOISE FREQUENCY
	25		Local 100mVPP Noise
	20		Remote 100mVPP Noise
°C)	15		Local 250mVPP Noise
	10		Remote 250mVPP Noise
(
TemperatureError	5
	0
	−5
	−10
	−15
	−20
	−25
	0	5	10	15

Frequency (MHz)

Figure 7.

	SHUTDOWN QUIESCENT CURRENT
	vs SCL CLOCK FREQUENCY
	500
	450
	400
	350
( A)	300
	250
Q	V	S	= 5.5V
I
	200
	150
	100
	50
	0		VS = 3.3V

1k

10k

100k

1M

10M

SCL CLock Frequency (Hz)

Figure 9.

QUIESCENT CURRENT vs CONVERSION RATE

	500
	450
	400
	350
A)	300					VS = 5.5V
(	250
Q
I	200
	150
	100						VS = 2.7V
	50
	0
	0.0625	0.125	0.25	0.5	1	2	4	8
			Conversion Rate (conversions/sec)

Figure 8.

SHUTDOWN QUIESCENT CURRENT vs SUPPLY VOLTAGE

	8
	7
	6
	5
( A)	4
Q
I
	3
	2
	1
	0
	2.5	3.0	3.5	4.0	4.5	5.0	5.5
				VS (V)

Figure 10.

Copyright © 2007–2008, Texas Instruments Incorporated

Submit Documentation Feedback

7

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421

TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

APPLICATION INFORMATION

The TMP421 (two-channel), TMP422 (three-channel), and TMP423 (four-channel) are digital temperature sensors that combine a local die temperature measurement channel and one, two, or three remote junction temperature measurement channels in a single SOT23-8 package. These devices are two-wire- and SMBus interface-compatible and are specified over a temperature range of –40°C to +125°C. The TMP421/22/23 each contain multiple registers for holding configuration information and temperature measurement results.

For proper remote temperature sensing operation, the TMP421 requires only a transistor connected between DXP and DXN pins. If the remote channel is not utilized, DXP can be left open or tied to GND.

The TMP422 requires transistors connected between DX1 and DX2 and between DX3 and DX4. Unused channels on the TMP422 must be connected to GND. The TMP423 requires a transistor connected to each positive channel (DXP1, DXP2, and DXP3), with the base of each channel tied to the common negative, DXN. For an unused channel, the TMP423 DXP pin can be left open or tied to GND.

The TMP421/22/23 SCL and SDA interface pins each require pull-up resistors as part of the communication bus. A 0.1μF power-supply bypass capacitor is recommended for local bypassing. Figure 11 shows a typical configuration for the TMP421; Figure 12 illustrates a typical application for the TMP422. Figure 13 illustrates a typical application for the TMP423.

				+5V
Transistor-connected configuration(1):					0.1µF	10kΩ	10kΩ
Series Resistance				8		(typ)	(typ)
RS(2)			1	V+	7
					SCL
			DXP
R		CDIFF					SMBus
	(2)
		(3)
	S		2				Controller
					6
			DXN	TMP421
					SDA
			3
			A1
			4
			A0	GND
Diode-connected configuration(1):				5
R	(2)
	S
		(3)
R	(2)	CDIFF
	S

(1)Diode-connected configuration provides better settling time. Transistor-connected configuration provides better series resistance cancellation.

(2)RS (optional) should be < 1.5kΩ in most applications. Selection of RS depends on application; see the Filtering section.

(3)CDIFF (optional) should be < 1000pF in most applications. Selection of CDIFF depends on application; see the Filtering section and Figure 6, Remote Temperature Error vs Differential Capacitance.

Figure 11. TMP421 Basic Connections

8

Submit Documentation Feedback

Copyright © 2007–2008, Texas Instruments Incorporated

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421 TMP422

TMP423

www.ti.com

SBOS398B–JULY 2007–REVISED MARCH 2008

				+5V
Transistor-connected configuration(1):					0.1µF	10kΩ	10kΩ
Series Resistance				8		(typ)	(typ)
RS(2)			1	V+	7
			DX1(4)		SCL
DXP1	(2)	(3)					SMBus
R		CDIFF
	S		2				Controller
			DX2(4)		6
DXN1					SDA
R	(2)			TMP422
	S		3
			DX3(4)
DXP2	(2)	(3)
R		CDIFF
	S		4
			DX4(4)
DXN2				GND
				5
Diode-connected configuration(1):
R	(2)
	S
		(3)
R	(2)	CDIFF
	S

(1)Diode-connected configuration provides better settling time. Transistor-connected configuration provides better series resistance cancellation.

(2)RS (optional) should be < 1.5kΩ in most applications. Selection of RS depends on application; see the Filtering section.

(3)CDIFF (optional) should be < 1000pF in most applications. Selection of CDIFF depends on application; see the Filtering section and Figure 6, Remote Temperature Error vs Differential Capacitance.

(4)TMP422 SMBus slave address is 1001 100 when connected as shown.

Figure 12. TMP422 Basic Connections

+5V

		Transistor-connected configuration(1):					0.1µF	10kΩ	10kΩ
		Series Resistance					8	(typ)	(typ)
		R	(2)
			S		1 DXP1		V+	7
							SCL
			(2)	(3)					SMBus
		RS		CDIFF	2				Controller
						DXP2	SDA 6
				(3)
			(2)	CDIFF			TMP423
		R
			S		3
						DXP3
R (2)	R (2)	R (2)		CDIFF	(3)
					4
S	S	S				DXN
							GND
							5
		Diode-connected configuration(1):
				R (2)
				S
						DXP
				R (2)		(3)
					CDIFF
				S
						DXN

(1)Diode-connected configuration provides better settling time. Transistor-connected configuration provides better series resistance cancellation.

(2)RS (optional) should be < 1.5kΩ in most applications. Selection of RS depends on application; see the Filtering section.

(3)CDIFF (optional) should be < 1000pF in most applications. Selection of CDIFF depends on application; see the Filtering section and Figure 6, Remote Temperature Error vs Differential Capacitance.

Figure 13. TMP423 Basic Connections

Copyright © 2007–2008, Texas Instruments Incorporated

Submit Documentation Feedback

9

Product Folder Link(s): TMP421 TMP422 TMP423

TMP421

TMP422

TMP423

SBOS398B–JULY 2007–REVISED MARCH 2008

SERIES RESISTANCE CANCELLATION

Series resistance in an application circuit that typically results from printed circuit board (PCB) trace resistance and remote line length is automatically cancelled by the TMP421/22/23, preventing what would otherwise result in a temperature offset. A total of up to 3kΩ of series line resistance is cancelled by the TMP421/22/23, eliminating the need for additional characterization and temperature offset correction. See the two Remote Temperature Error vs Series Resistance typical characteristic curves (Figure 4 and Figure 5) for details on the effects of series resistance and power-supply voltage on sensed remote temperature error.

DIFFERENTIAL INPUT CAPACITANCE

The TMP421/22/23 tolerate differential input capacitance of up to 1000pF with minimal change in temperature error. The effect of capacitance on sensed remote temperature error is illustrated in Figure 6, Remote Temperature Error vs Differential Capacitance.

TEMPERATURE MEASUREMENT DATA

Temperature measurement data may be taken over an operating range of –40°C to +127°C for both local and remote locations.

However, measurements from –55°C to +150°C can be made both locally and remotely by reconfiguring the TMP421/22/23 for the extended temperature range, as described below.

Temperature data that result from conversions within the default measurement range are represented in binary form, as shown in Table 1, Standard Binary column. Note that although the device is rated to only measure temperatures down to –55°C, it may read temperatures below this level. However, any temperature below –64°C results in a data value of –64 (C0h). Likewise, temperatures above +127°C result in a value of 127 (7Fh). The device can be set to measure over an extended temperature range by changing bit 2 (RANGE) of Configuration Register 1

www.ti.com

from low to high. The change in measurement range and data format from standard binary to extended binary occurs at the next temperature conversion. For data captured in the extended temperature range configuration, an offset of 64 (40h) is added to the standard binary value, as shown in the Extended Binary column of Table 1. This configuration allows measurement of temperatures as low as –64°C, and as high as +191°C; however, most temperature-sensing diodes only measure with the range of –55°C to +150°C. Additionally, the TMP421/22/23 are rated only for ambient temperatures ranging from –40°C to +125°C. Parameters in the Absolute Maximum Ratings table must be observed.

Table 1. Temperature Data Format (Local and

Remote Temperature High Bytes)

LOCAL/REMOTE TEMPERATURE REGISTER

HIGH BYTE VALUE (1°C RESOLUTION)

TEMP	STANDARD BINARY(1)		EXTENDED BINARY(2)
(°C)	BINARY	HEX	BINARY	HEX
–64	1100 0000	C0	0000 0000	00
–50	1100 1110	CE	0000 1110	0E
–25	1110 0111	E7	0010 0111	27
0	0000 0000	00	0100 0000	40
1	0000 0001	01	0100 0001	41
5	0000 0101	05	0100 0101	45
10	0000 1010	0A	0100 1010	4A
25	0001 1001	19	0101 1001	59
50	0011 0010	32	0111 0010	72
75	0100 1011	4B	1000 1011	8B
100	0110 0100	64	1010 0100	A4
125	0111 1101	7D	1011 1101	BD
127	0111 1111	7F	1011 1111	BF
150	0111 1111	7F	1101 0110	D6
175	0111 1111	7F	1110 1111	EF
191	0111 1111	7F	1111 1111	FF

(1)Resolution is 1°C/count. Negative numbers are represented in two's complement format.

(2)Resolution is 1°C/count. All values are unsigned with a –64°C offset.

10

Submit Documentation Feedback

Copyright © 2007–2008, Texas Instruments Incorporated

Product Folder Link(s): TMP421 TMP422 TMP423