Datasheet

ManualsBrandsMicrochip ManualsDigitalTemperature sensor MSOP-8

TCN75A

Features

• Temperature-to-Digital Converter

• Accuracy with 12-bit Resolution:

- ±0.5°C (typ.) at +25°C

- ±3°C (max.) from +25°C to +100°C

• User-selectable Resolution: 9 – 12 bits

• Operating Voltage Range: 2.7V to 5.5V

• 2-wire Interface: I

C™ Compatible

• Operating Current: 200 µA (typ.)

• Shutdown Current: 2 µA (max.)

• 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 ±1.5°C (typ.) accuracy.

The TCN75A product comes with user-programmable

registers that provide flexibility for temperature-sensing

applications. The register settings allow user-select-

able, 9-bit to 12-bit temperature measurement resolu-

tion, 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 thermo-

stat operation, or as temperature event interrupt output

for microprocessor-based systems.

This sensor has an industry standard 2-wire, I

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

TCN75A

SDA

SCLK

I/O Ports

PULL-UP

PICmicro

SDA

GND

ALERT

SCLK

Microcontroller

ALERT

SDA

GND

ALERT

SCLK

8-Pin SOIC, MSOP

TCN75A

2-Wire Serial Temperature Sensor

Summary of content (30 pages)

PAGE 1
TCN75A 2-Wire Serial Temperature Sensor Features Description • Temperature-to-Digital Converter • Accuracy with 12-bit Resolution: - ±0.5°C (typ.) at +25°C - ±3°C (max.) from +25°C to +100°C • User-selectable Resolution: 9 – 12 bits • Operating Voltage Range: 2.7V to 5.5V • 2-wire Interface: I2C™ Compatible • Operating Current: 200 µA (typ.) • Shutdown Current: 2 µA (max.) • Power-saving One-shot Temperature Measurement • Available Packages: MSOP-8, SOIC-8 Microchip Technology Inc.
PAGE 2
TCN75A 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings † VDD ....................................................................... 6.0V †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.
PAGE 3
TCN75A DIGITAL INPUT/OUTPUT PIN CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground and TA = -40°C to +125°C. Parameters Sym Min Typ Max Units Conditions Serial Input/Output (SCLK, SDA, A0, A1, A2) Input High-level Voltage VIH 0.7 VDD — — V Low-level Voltage VIL — — 0.3 VDD V Input Current IIN -1 — +1 µA Low-level Voltage VOL — — 0.4 V IOL= 3 mA High-level Current IOH — — 1 µA VOH = 5V VOL = 0.
PAGE 4
TCN75A SERIAL INTERFACE TIMING SPECIFICATIONS Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, TA = -40°C to +125°C, CL = 80 pF and all limits measured to 50% point. Parameters 2-Wire Sym Min Typ Max Units Conditions I2 C™ Compatible Interface Serial Port Frequency fSC 0 — 400 kHz Clock Period tSC 2.5 — — µs Low Clock tLOW 1.3 — — µs High Clock tHIGH 0.
PAGE 5
TCN75A 2.0 TYPICAL PERFORMANCE CURVES 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. Note: Unless otherwise noted: VDD = 2.7V to 5.
PAGE 6
TCN75A Note: Unless otherwise noted: VDD = 2.7V to 5.5V. 145 VOL = 0.6V 42 VDD = 5.5V VDD = 3.3V VDD = 2.7V 36 30 24 18 12 Temperature Data (°C) ALERT and SDA I OL (mA) 48 Average of 10 samples per package 125 105 85 65 SOIC 45 MSOP 25 27°C (Air) to 125°C (Oil bath) 6 5 -55 -35 -15 5 25 45 TA (°C) 65 85 105 125 FIGURE 2-7: ALERT and SDA IOL vs. Ambient Temperature. -2 0 FIGURE 2-9: vs. Time. 2 4 6 8 10 12 14 16 18 20 Time (s) TCN75A Thermal Response ALERT and SDA V OL (V) 0.
PAGE 7
TCN75A 3.0 PIN DESCRIPTION The descriptions of the pins are listed in Table 3-1. TABLE 3-1: MSOP, SOIC 3.
PAGE 8
TCN75A 4.0 FUNCTIONAL DESCRIPTION The TCN75A temperature sensor consists of a bandgap type temperature sensor, a ΣΔ Analog-to-Digital Converter (ADC), user-programmable registers and a 2-wire I2C protocol-compatible serial interface. 4.1 Temperature Sensor The TCN75A uses the difference in the base-emitter voltage of a transistor while its collector current is changed from IC1 to IC2.
PAGE 9
TCN75A 4.3 Registers Resolution The TCN75A has four registers that are user-accessible. These registers are specified as the Ambient Temperature (TA) register, the Temperature Limit-set (TSET) register, the Temperature Hysteresis (THYST) register and device Configuration (CONFIG) register. One-Shot Shutdown Fault Queue The Ambient Temperature register is a read-only register and is used to access the ambient temperature data. The data from the ADC is loaded in parallel in the register.
PAGE 10
TCN75A 4.3.1 AMBIENT TEMPERATURE REGISTER (TA) conversion in the background. The decimal code to ambient temperature conversion is shown in Equation 4-2: The TCN75A has a 16-bit read-only Ambient Temperature register that contains 9-bit to 12-bit temperature data. This data is formatted in two’s complement. The bit assignments, as well as the corresponding resolution, is shown in the register assignment below.
PAGE 11
TCN75A 4.3.2 TEMPERATURE LIMIT-SET REGISTER (TSET) The TCN75A has a 16-bit read/write Temperature Limit-Set register (TSET) which contains a 9-bit data in two’s compliment format. This data represents a maximum temperature limit. If the ambient temperature exceeds this specified limit, the TCN75A asserts an alert output. (Refer to Section 4.3.4.3 “ALERT Output Configuration”). This register uses the nine Most Significant bits (MSbs) and all other bits are don’t cares.
PAGE 12
TCN75A 4.3.3 TEMPERATURE HYSTERESIS REGISTER (THYST) The TCN75A has a 16-bit read/write Temperature Hysteresis register that contains a 9-bit data in two’s compliment format. This register is used to set a hysteresis for the TSET limit. Therefore, the data represents a minimum temperature limit. If the ambient temperature drifts below the specified limit, the TCN75A asserts an alert output (refer to Section 4.3.4.3 “ALERT Output Configuration”).
PAGE 13
TCN75A 4.3.4 SENSOR CONFIGURATION REGISTER (CONFIG) The TCN75A has an 8-bit read/write Configuration register that allows the user to select the different features. These features include shutdown, ALERT output select as comparator or interrupt output, ALERT output polarity, fault queue cycle, temperature measurement resolution and One-shot mode (single conversion while in shutdown). These functions are described in detail in the following sections.
PAGE 14
TCN75A 4.3.4.1 4.3.4.3 Shutdown Mode The Shutdown mode disables all power-consuming activities (including temperature sampling operations) while leaving the serial interface active. The device consumes 2 µA (max.) in this mode. It remains in this mode until the Configuration register is updated to enable continuous conversion or until power is recycled.
PAGE 15
TCN75A 4.3.4.6 Fault Queue 4.4 The fault queue feature can be used as a filter to lessen the probability of spurious activation of the ALERT pin. TA must remain above TSET for the consecutive number of conversion cycles selected using the Fault Queue bits. Bit 3 and bit 4 of CONFIG can be used to select up to six fault queue cycles. For example, if six fault queues are selected, TA must be greater than TSET for six consecutive conversions before ALERT is asserted as a comparator or an interrupt output.
PAGE 16
TCN75A 5.0 SERIAL COMMUNICATION 5.1 2-Wire I2C™ Compatible Interface The TCN75A serial clock input (SCLK) and the bidirectional Serial Data (SDA) line form a 2-wire bidirectional serial port for communication.
PAGE 17
TCN75A 5.
PAGE 18
TCN75A Write 1-byte Data 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C 1 2 3 4 5 6 7 8 0 0 0 0 0 0 P 1 P 0 1 2 3 4 5 6 7 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 SCLK SDA S A K Address Byte A C K Pointer A C K P Data TCN75A TCN75A TCN75A Write 2-byte Data 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C 1 2 3 4 5 6 7 8 0 0 0 0 0 0 P 1 P 0 SCLK SDA S A K Address Byte Pointer TCN75A TCN75A 1 2 3 4 5 6 7 8 D D D D D D D 15 14
PAGE 19
TCN75A Register Pointer Setting for Continuous Reception 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C K 1 2 3 4 5 6 7 8 0 0 0 0 0 0 P 1 P 0 SCLK SDA S A Address Byte A C K Pointer TCN75A TCN75A Receive 1-byte Data 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 R C 1 2 3 4 5 6 7 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 SCLK SDA S A K Address Byte N A K P Data Master TCN75A Receive Another 1-byte Data 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 R
PAGE 20
TCN75A Register Pointer Setting for Continuous Reception 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C K 1 2 3 4 5 6 7 8 0 0 0 0 0 0 P 1 P 0 SCLK SDA S A Address Byte A C K Pointer TCN75A TCN75A Receive 2-byte Data S 1 2 3 4 5 6 7 1 0 0 1 A 2 A 1 A 0 8 1 2 3 4 5 6 7 8 D D D D D D K 15 14 13 12 11 10 9 D 8 A R C D A C K 1 2 3 4 5 6 7 8 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0 MSB Data Address Byte N A K P LSB Data Master TCN75A Master
PAGE 21
TCN75A 6.0 APPLICATIONS INFORMATION 6.1 Connecting to the Serial Bus The SDA and SCLK serial interface are open-drain pins that require pull-up resistors. This configuration is shown in Figure 6-1. PICmicro® Microcontroller VDD FIGURE 6-1: Interface. R R TCN75A SDA SCLK 6.3 Pull-up Resistors On Serial Typical Application Microchip provides several microcontroller product lines with Master Synchronous Serial Port Modules (MSSP) that include the I2C interface mode.
PAGE 22
TCN75A 7.0 PACKAGING INFORMATION 7.1 Package Marking Information Example: 8-Lead MSOP N75A/E 542256 XXXXX YWWNNN 8-Lead SOIC (150 mil) XXXXXXXX XXXXYYWW NNN Legend: XX...X Y YY WW NNN e3 * Note: DS21935A-page 22 Example: TCN75A VOA0542 256 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free.
PAGE 23
TCN75A 8-Lead Plastic Micro Small Outline Package (UA) (MSOP) E E1 p D 2 B n 1 α A2 A c φ A1 (F) L β Units Dimension Limits n p MIN INCHES NOM 8 .026 BSC .033 .193 TYP. .118 BSC .118 BSC .024 .037 REF .006 .012 - MAX MILLIMETERS* NOM 8 0.65 BSC 0.75 0.85 0.00 4.90 BSC 3.00 BSC 3.00 BSC 0.40 0.60 0.95 REF 0° 0.08 0.22 5° 5° - MIN Number of Pins Pitch A .043 Overall Height A2 .030 .037 Molded Package Thickness .000 .006 A1 Standoff E Overall Width E1 Molded Package Width D Overall Length L .
PAGE 24
TCN75A 8-Lead Plastic Small Outline (OA) – Narrow, 150 mil Body (SOIC) E E1 p D 2 B n 1 h α 45° c A2 A φ β L Units Dimension Limits n p Number of Pins Pitch Overall Height Molded Package Thickness Standoff § Overall Width Molded Package Width Overall Length Chamfer Distance Foot Length Foot Angle Lead Thickness Lead Width Mold Draft Angle Top Mold Draft Angle Bottom * Controlling Parameter § Significant Characteristic A A2 A1 E E1 D h L φ c B α β MIN .053 .052 .004 .228 .146 .189 .010 .
PAGE 25
TCN75A APPENDIX A: REVISION HISTORY Revision A (January 2005) • Original release of this document. © 2005 Microchip Technology Inc.
PAGE 27
TCN75A PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. X /XX Device Temperature Range Package Device: TCN75A: Temperature Range: V Package: OA UA Examples: a) b) TCN75AVOA TCN75AVUA 8LD SOIC package. 8LD MSOP package. Temperature Sensor = -40°C to +125°C = Plastic SOIC, (150 mil Body), 8-lead = Plastic Micro Small Outline (MSOP), 8-lead © 2005 Microchip Technology Inc.
PAGE 29
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
PAGE 30
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