TCN75

TCN75 TELCOM | Alldatasheet

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PRELIMINARY INFORMATION2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR TCN75-04 6/16/97 2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR

FEATURES

n Solid State Temperature Sensing; 2°C Accuracy (Typ.) n Operates from – 55°C to +125°C n Programmable Trip Point and Hysteresis with Power-up Defaults n Standard 2-Wire Serial Interface n Thermal Event Alarm Output Functions as Interrupt or Comparator / Thermostat Output n Up to 8 TCN75's May Share the Same Bus n Shutdown Mode for Low Standby Power Consumption 1µA (Typ.) Shutdown Mode n 8-Pin Plastic DIP, SOIC, and MSOP Packaging TYPICAL APPLICATIONS n Thermal Protection for High Performance CPU's n Solid-State Thermometer n Fire/Heat Alarms n Thermal Management in Electronic Systems: Computers Telecom Racks Power Supplies / UPS* / Amplifiers n Copiers / Office Electronics n Consumer Electronics n Process Control GENERAL DESCRIPTION The TCN75 is a serially programmable temperature sensor that notifies the host controller when ambient tem- FUNCTIONAL BLOCK DIAGRAM TCN75

ORDERING INFORMATION

Part No. Voltage (V) Package Temp. Range TCN75-3.3MOA 3.3 8-Pin SOIC – 55 °C to +125°C TCN75-5.0MOA 5.0 8-Pin SOIC – 55 °C to +125°C TCN75-3.3MPA 3.3 8-Pin PDIP – 55 °C to +125°C TCN75-5.0MPA 5.0 8-Pin PDIP – 55 °C to +125°C TCN75-3.3MUA 3.3 8-MSOP – 55 °C to +125°C TCN75-5.0MUA 5.0 8-MSOP – 55 °C to +125°C PIN CONFIGURATIONS TCN75MOA TCN75MUA SCL INT/CMPTR A1 GND TCN75MPA 8-Pin Plastic DIP 8-Pin SOIC 8-Pin MSOP SDA V DD SCL INT/CMPTR GND SDA SCL INT/CMPTR GND SDA VDD VDD Control Logic TCN75 INT/CMPTR Register Set TSET THYST Configuration A 0 VDD Temp Sensor SCL SDA A 1 A 2 Temperature

9 Bit

ΔΣ A/D Converter Two Wire Serial Port Interface perature exceeds a user-programmed setpoint. Hysteresis is also programmable. The INT/CMPTR output is program- mable as either a simple comparator for thermostat opera- tion or as a temperature event interrupt. Communication with the TCN75 is accomplished via a two-wire bus that is compatible with industry standard protocols. This permits reading the current temperature, programming the setpoint and hysteresis, and configuring the device. The TCN75 powers up in Comparator Mode with a default setpoint of 80°C with 5°C hysteresis. Defaults allow independent operation as a stand-alone thermostat. A shut- down command may be sent via the 2-wire bus to activate the low-power standby mode. Address selection inputs allow up to eight TCN75's to share the same 2-wire bus for multi-zone monitoring. All registers can be read by the host and the INT/ CMPTR output's polarity is user programmable. Both polled and interrupt driven systems are easily accommodated. Small physical size, low installed cost, and ease of use make the TCN75 an ideal choice for implementing sophisticated system management schemes. TelCom Semiconductor reserves the right to make changes in the circuitry and specifications of its devices.

SENSOR AND THERMAL MONITOR TCN75 PRELIMINARY INFORMATION TCN75-04 6/16/97 ELECTRICAL CHARACTERISTICS: VDD = 2.7V – 5.5V, – 55°C ≤ (TA = TJ) ≤ 125°C, unless otherwise noted. Symbol Parameter Test Conditions Min Typ Max Unit Power Supply VDD Power Supply Voltage 2.7 — 5.5 V IDD Operating Current Serial Port Inactive (TA = TJ = 25°C) — 0.250 — mA Serial Port Active — — 1.0 IDD1 Standby Supply Current Shutdown Mode, Serial Port Inactive — 1 — µA (TA = TJ = 25°C) INT/CMPTR Output IOL Sink Current: INT/CMPTR, SDA Note 1 — 1 4 mA Outputs tTRIP INT/CMPTR Response Time User Programmable 1 — 6 t CONV VOL Output Low Voltage I OL = 4.0mA — — 0.8 V Temp-to-Bits Converter ΔT Temperature Accuracy (Note 2) – 55 °C ≤ TA ≤ +125°C— ±3— °C VDD = 3.3V : TCN75-3.3MOA, TCN75-3.3MPA, TCN75-3.3MUA V DD = 5.0V: TCN75-5.0MOA, TCN75-5.0MPA, TCN75-5.0 MUA tCONV Conversion Time — 100 — msec TSET(PU) TEMP Default Value Power Up — 80 — °C THYST(PU) THYST Default Value Power Up — 75 — °C 2-Wire Serial Bus Interface VIH Logic Input High V DD x 0.7 — — V VIL Logic Input Low — — V DD x 0.3 V VOL Logic Output Low I OL = 3mA — — 0.4 V C IN Input Capacitance SDA, SCL — 15 — pF ILEAK I/O Leakage (TA = TJ = 25°C) — ±100 — pA IOL(SDA) SDA Output Low Current — — 6 mA SERIAL PORT TIMING: 2.7V ≤ VDD ≤ 5.5V; – 55°C ≤ (TA = TJ ) ≤ 125°C, CL = 80pf, unless otherwise noted. Symbol Parameter Test Conditions Min Typ Max Unit fSC Serial Port Frequency 0 100 400 kHz tLOW Low Clock Period 1250 — — nsec tHIGH High Clock Period 1250 — — nsec tR SCL and SDA Rise Time — — 250 nsec tF SCL and SDA Fall Time — — 250 nsec tSU(START) Start Condition Setup Time 1250 — — nsec (for repeated Start Condition) ABSOLUTE MAXIMUM RATINGS* DD + 0.3V) Thermal Resistance (Junction to Ambient) *This is a stress rating only and functional operation of this device at these or any other conditions above those indicated in the operations sections of this specification is not implied.

PRELIMINARY INFORMATION2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR TCN75-04 6/16/97 SERIAL PORT TIMING (Cont.): 2.7V ≤ VDD ≤ 5.5V; – 55°C ≤ (TA = TJ ) ≤ 125°C, CL = 80pf, unless otherwise noted. Symbol Parameter Test Conditions Min Typ Max Unit tH(START) Start Condition Hold Time 1250 — — nsec tDSU Data in Setup Time to SCL High 100 — — nsec tDH Data in Hold Time after SCL Low 0 — — nsec tSU(STOP) Stop Condition Setup Time 1250 — — nsec tIDLE Bus Free Time Prior to New 1250 — — nsec Transition NOTES: 1. Output current should be minimized for best temperature accuracy. Power dissipation within the TCN75 will cause self-heating and temperature drift. At maximum rated output current and saturation voltage, 4mA and 0.8V, respectively, the error amounts to 0.352°C for the PDIP, and 0.544°C for the SOIC. 2. All part types of the TCN75 will operate properly over the wider power supply range of 2.7V to 5.5V. Each part type is tested and specified for rated accuracy at its nominal supply voltage. As VDD varies from the nominal value, accuracy will degrade 1°C/V of VDD change. 3. Human body model, 100pF discharged through a 1.5k resistor, machine model, 200pF discharged directly into each pin. PIN DESCRIPTION Pin Number Symbol Description 1 SDA Bidirectional Serial Data. 2 SCL Serial Data Clock Input. 3 INT/CMPTR Interrupt or Comparator Output. 4 GND System Ground. 5A 2 Address Select Pin (MSB). 6A 1 Address Select Pin. 7A 0 Address Select Pin (LSB). 8V DD Power Supply Input. DETAILED DESCRIPTION A typical TCN75 hardware connection is shown in Figure 1. Serial Data (SDA) Bidirectional. Serial data is transferred in both directions using this pin. Serial Clock (SCL) Input. Clocks data into and out of the TCN75. INT/CMPTR Open Collector, Programmable Polarity. In Comparator Mode, unconditionally driven active any time temperature exceeds the value programmed into the T SET register. INT/ CMPTR will become inactive when temperature subse- quently falls below the T HYST setting. (See Register Set and Programmer's Model.) In Interrupt Mode, INT/CMPTR is also made active by TEMP exceeding TSET ; it is uncondition- ally reset to its inactive state by reading any register via the 2-wire bus. If and when temperature falls below T HYST , INT/ CMPTR is again driven active. Reading any register will clear the T HYST interrupt. In Interrupt Mode, the INT/CMPTR output is unconditionally reset upon entering Shutdown Mode. If programmed as an active-low output, it can be wire-ORed with any number of other open collector devices. Most systems will require a pull-up resistor for this configu- ration. Note that current sourced from the pull-up resistor causes power dissipation and may cause internal heating of the TCN75. To avoid affecting the accuracy of ambient temperature readings, the pull-up resistor should be made as large as possible. INT/CMPTR's output polarity may be programmed by writing to the INT/CMPTR POLARITY bit in the CONFIG register. The default is active low. Address (A2, A1, A0) Inputs. Sets the three least significant bits of the TCN75 8-bit address. A match between the TCN75's address and the address specified in the serial bit stream must be made to initiate communication with the TCN75. Many protocol- compatible devices with other addresses may share the same 2-wire bus. Slave Address The four most significant bits of the Address Byte (A6, A5, A4, A3) are fixed to 1001[B]. The states of A2, A1 and

1001 A 2 A 1 A 0

the TCN75 is in Comparator Mode or Interrupt Mode. in shutdown mode when the TCN75 is in comparator mode. necessary on this pin since it is an open-drain output. CMPTR when in Interrupt Mode. CMPTR will be RESET upon entering shutdown mode. Register Set and Programmer's Model. Transmitter The device sending data to the bus. Receiver The device receiving data from the bus. terminating transfers (STOP). Slave The device addressed by the master. Figure 2. All data transfers have two phases; and all bytes

Figure 2. Timing Diagrams

000000 D 1 D 0

000000 D 1 D 0 D 7 D 6 D 5 D 4 D 3 D 2 D 1 D 0D6 D5 D4 D2 D3 D1 D01 A 2A 1A 0 R/W00

000000 D 1 D 0 0 0 0 D4 D2 D3 D1 D01 A 2A 1A 0 R/W00

PRELIMINARY INFORMATION2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR TCN75-04 6/16/97 Configuration Register (CONFIG), 8-bits, Read/Write Configuration Register (CONFIG) Must Be Set To Zero Fault INT/CMPTR. COMP/ Shut- Queue POLARITY INT. Down D0: Shutdown: 0 = Normal Operation 1 = Shutdown Mode D1: CMPTR/INT: 0 = Comparator Mode 1 = Interrupt Mode D2: INT/CMPTR POLARITY: 0 = Active Low 1 = Active High D3 - D4: Fault Queue: Number of sequential temperature- to-digital conversions with the same result before the INT/CMPTR output is updated: D4 D3 Number of Conversions 0 0 1 (Power-up-default) 01 2 10 4 11 6 REGISTER SET AND PROGRAMMER'S MODEL Register (POINT), 8-bits, Write-only Pointer Register (POINT) Must Be Set To Zero Pointer Register Selection via the Pointer Register: D1 D0 Register Selection 0 0 TEMP 0 1 CONFIG

10 T HYST

11 T SET

SENSOR AND THERMAL MONITOR TCN75 PRELIMINARY INFORMATION TCN75-04 6/16/97 The TCN75's register set is summarized below Name Description Width Read Write Notes TEMP Ambient Temperature 16 X 2's Complement Format TSET Temperature Setpoint 16 X X 2's Complement Format THYST Temperature Hysteresis 16 X X 2's Complement Format POINT Register Pointer 8 X X CONFIG Configuration Register 8 X X Temperature to Digital Value Conversion Temperature Binary Value HEX Value +125°C 0 11111010 0FA +25°C 0 00110010 032 +0.5°C 0 00000001 001 0°C 0 00000000 00 – 0.5°C 1 11111111 1FF – 25°C 1 11001110 1CE – 40°C 1 10110000 1B0 – 55°C 1 10010010 192 Temperature Register (TEMP) MSB D7 D6 D5 D4 D3 D2 D1 LSB X X X X X X X Temperature Setpoint (TSET ) and Hysteresis (THYST ) Register, 16-bits, Read-Write: Temperature Setpoint Register (TSET ) MSB D7 D6 D5 D4 D3 D2 D1 LSB X X X X X X X Hysteresis Register (THYST ) MSB D7 D6 D5 D4 D3 D2 D1 LSB X X X X X X X Temperature (TEMP) Register, 16-bits, Read-only The binary value in this register represents ambient temperature following a conversion cycle. In the TEMP, TSET , and THYST registers, each unit value represents one-half degree (Celsius). The value is in 2's - complement binary format such that a reading of 000000000b corresponds to 0°C. Examples of this temperature to binary value relationship are shown in the following table.

PRELIMINARY INFORMATION2-WIRE SERIAL TEMPERATURE SENSOR AND THERMAL MONITOR TCN75-04 6/16/97 PACKAGE DIMENSIONS 8-Pin Plastic DIP 3°MIN. PIN 1 .260 (6.60) .240 (6.10) .045 (1.14) .030 (0.76) .070 (1.78) .045 (1.14) .400 (10.16) .348 (8.84) .200 (5.08) .140 (3.56) .150 (3.81) .115 (2.92) .110 (2.79) .090 (2.29) .022 (0.56) .015 (0.38) .040 (1.02) .008 (0.20) .310 (7.87) .290 (7.37) .400 (10.16) .310 (7.87) Dimensions: inches (mm) .050 (1.27) TYP. 8°MAX. PIN 1 .244 (6.20) .228 (5.79) .157 (3.99) .150 (3.81) .197 (5.00) .189 (4.80) .018 (0.46) .014 (0.36) .010 (0.25) .004 (0.10) .069 (1.75) .007 (0.18) .050 (1.27) .016 (0.40) 8-Pin SOIC

SENSOR AND THERMAL MONITOR TCN75 PRELIMINARY INFORMATION TCN75-04 6/16/97 TelCom Semiconductor H.K. Ltd.

10 Sam Chuk Street, Ground Floor

San Po Kong, Kowloon Hong Kong TEL: 852-2324-0122 FAX: 852-2354-9957 Sales Offices TelCom Semiconductor

1300 Terra Bella Avenue

P.O. Box 7267 Mountain View, CA 94039-7267 TEL: 415-968-9241 FAX: 415-967-1590 E-Mail: liter@c2smtp.telcom-semi.com TelCom Semiconductor Austin Product Center 9101 Burnet Rd. Suite 214 Austin, TX 78758 TEL: 512-873-7100 FAX: 512-873-8236 Printed in the U.S.A. 8-Pin MSOP Dimensions: inches (mm) .122 (3.10) .114 (2.90) .122 (3.10) .114 (2.90) .043 (1.10) MAX. .006 (0.15) .002 (0.05) .016 (0.40) .010 (0.25) .197 (5.00) .187 (4.80) PIN 1 .008 (0.20) .005 (0.13) .028 (0.70) .016 (0.40) 6°MAX. .026 (0.65) TYP.