Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 TMP7 IC Thermometer with Seven Segment and Serial Output General Description The TMP7 is thermometer IC with seven segment outputs for non multiplexed displays. An inexpensive thermister is used as the temperature sensor. The IC supports 4 scales: degrees C, degrees F, percentage, and raw A/D output. Serial output is also provided for RS-232, USB, or Ethernet operation. The chip provides output polarity control. The TMP7 has internal pull resistors on inputs to minimize additional parts. A .1 uF bypass capacitor is suggested across the VDD and VSS pins. The part uses the standard 28 pin .3 inch width SOIC and DIP packages. Features • Degrees C, Degrees F, percentage • • • • • • • • • • • • • • • and raw data outputs. Can drive seven segment displays and serial devices. Minimum and maximum temperatures. Applications • Temperature displays. • Remote temperature sensing. • Remote 12 bit A/D converter. • Environmental and process controls . • Percentage displays. Percentage scale. 12 bit A/D converter Few external parts required. Low power consumption 20 mA typical. Supply voltage 3.3 to 5.25 volts. All timing internally generated. On chip input resistors. Output polarity select. TTL and CMOS compatible. Part is in full production. SOIC and DIP 28 Pin Package. ROHS Compliant Low EMI Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 1 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Example Circuit – Stand Alone Thermometer OPTIONAL 3RD COMMON ANODE DISPLAY VCC COM B G TMP7 SEG3G SEG3C SEG3B VCC 25 VDD NC NC SEGLG SEGLF SEGLE SEGLD SEGLC SEGLB SEGLA SOUT- 10K NTC t 24 OPTIONAL SWITCHES C LEFT COMMON ANODE DISPLAY VCC 28 19 9 MIN G C B VCC 10K MAX 10 5 2 4 3 1 26 27 14 23 6 22 7 21 8 20 G F E D C B A A COM F B G E C D RIGHT COMMON ANODE DISPLAY TEMP SEGRG SEGRF SEGRE SEGRD SEGRC SEGRB SEGRA MAXMINFARH SCALE POL VSS 18 11 17 12 16 13 15 G F E D C B A VCC A COM F B G E C D F/C Example Circuit – Ethernet Thermometer +3.3 10K 10K NTC t FARH SEG3B MINMAXSEG3C SEGLF SEGLD SEGLB NC SEG3G SEGRF SEGRD SEGRB VSS VDD POL SCALE SOUTTEMP SEGLG SEGLE SEGLC SEGLA NC SEGRG SEGRE SEGRC SEGRA +3.3 28 27 26 25 24 23 22 21 20 19 18 17 16 15 +3.3 LANTRONIX XPORT 1 2 3 4 5 6 7 8 GND +3.3 -POR OUT IN CP1 CP2 CP3 ETHERNET TMP7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 2 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Example Circuit – USB Thermometer VCC .01 BEAD .1 4.7 .1 USB 16 USBM 15 USBP 19 27 28 8 24 CASE -RST OSCI OSCO NC NC GND GND GND AGND TEST 1 2 3 4 5 VCC VCCIO 3VOUT 20 4 17 FT232-SSOP TMP7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 VCC 10K 10K NTC t FARH SEG3B MINMAXSEG3C SEGLF SEGLD SEGLB NC SEG3G SEGRF SEGRD SEGRB VSS VCC 28 27 26 25 24 23 22 21 20 19 18 17 16 15 VDD POL SCALE SOUTTEMP SEGLG SEGLE SEGLC SEGLA NC SEGRG SEGRE SEGRC SEGRA 7 18 21 25 26 REFER TO FT232 DATASHEET FOR MORE DETAILS TXD RXD DTR -CTS RTS RI DSR DCD CBUS0 CBUS1 CBUS2 CBUS3 CBUS4 1 5 2 11 3 6 9 10 23 22 13 14 12 Example Circuit – RS-232 Thermometer 1 .1 3 4 .1 5 11 10 12 U2 SEE NOTES VCC V+ 2 .1 C1C2+ V- T1in T1out T2in T2out R1out R2out R1in RS232 DB9S .1 14 7 13 8 1 2 3 4 5 6 7 8 9 8 VCC 10K TXD RXD GND 10K NTC t 1 2 3 4 5 6 7 8 9 10 11 12 13 14 FARH SEG3B MINMAXSEG3C SEGLF SEGLD SEGLB NC SEG3G SEGRF SEGRD SEGRB VSS VDD POL SCALE SOUTTEMP SEGLG SEGLE SEGLC SEGLA NC SEGRG SEGRE SEGRC SEGRA VCC 28 27 26 25 24 23 22 21 20 19 18 17 16 15 15 R2in TMP7 6 C2- GND 9 C1+ VCC 16 VCC U2= MAX232 FOR 5V RS232 U2= MAX3232 FOR 3V RS232 Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 3 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Example Circuit – Percentage Display OPTIONAL 3RD COMMON ANODE DISPLAY VCC COM B G TMP7 SEG3G SEG3C SEG3B 10 5 2 G C B C LEFT COMMON ANODE DISPLAY VCC VCC 28 19 9 25 VCC 24 4 3 1 26 27 14 VDD NC NC SOUT- SEGLG SEGLF SEGLE SEGLD SEGLC SEGLB SEGLA 23 6 22 7 21 8 20 A COM F B G E C D RIGHT COMMON ANODE DISPLAY TEMP MAXMINFARH SCALE POL VSS G F E D C B A SEGRG SEGRF SEGRE SEGRD SEGRC SEGRB SEGRA 18 11 17 12 16 13 15 G F E D C B A VCC A COM F B G E C D Connection Diagram TMP7 1 2 3 4 5 6 7 8 9 10 11 12 13 14 FARH SEG3B MINMAXSEG3C SEGLF SEGLD SEGLB NC SEG3G SEGRF SEGRD SEGRB VSS VDD POL SCALE SOUTTEMP SEGLG SEGLE SEGLC SEGLA NC SEGRG SEGRE SEGRC SEGRA 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 4 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Pin Description Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Description FARH SEG3B MINMAXSEG3C SEGLF SEGLD SEGLB NC SEG3G SEGRF SEGRD SEGRB VSS Pin # 28 27 26 25 24 23 22 21 20 19 18 17 16 15 Description VDD POL SCALE SOUTTEMP SEGLG SEGLE SEGLC SEGLA NC SEGRG SEGRE SEGRC SEGRA POL Polarity input. If this pin is open or high, the “on” segments will have a high level on the SEG outputs of the chip. If this pin is low or grounded “on” segments will output as a low on the SEG pins. This pin is read once at power up and has a built in pull up resistor. TEMP This is the analog input for the temperature. A 10K precision resistor and a 10K NTC thermister are connected to this input for temperature measurement. The thermister should have a B25/B5 ratio of 3977K. These thermisters are available from Murata, Vishay, US Sensor, and other companies. This input is a sensitive analog input and should be protected from noise. This input may also be connected to any analog device with an output of 0 to VCC volts. In this case, the input must be protected from voltages greater than VCC or lower than ground. MINThis optional input displays the lowest temperature since power was applied. If both MIN- and MAX- are low, the minimum temperature is reset to the current temperature. This input has a built in pull up resistor. This input has no effect on the serial output. MAXThis optional input displays the highest temperature since power was applied. If both MIN- and MAX- are low, the maximum temperature is reset to the current temperature. This input has a built in pull up resistor. This input has no effect on the serial output. SCALE and FARH These two inputs select the scale to be used, degrees C, degrees F, Percentage, or Raw data. These inputs have a built in pull up resistors. These inputs are read before every display update and serial output. Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 5 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 SCALE Open or high Open or high Ground or low Ground or low FARH Open or high Ground or low Open or high Ground or low Output Degrees Fahrenheit Degrees Celsius Percentage (0-100) Raw analog count In the Celsius scale, the output ranges from –40 to 150. In the Fahrenheit scale, the output ranges from -40 to 199. In the percentage mode, the output ranges from 0-100. (101 counts) A small resistor on the VCC side of the input potentiometer or a voltage divider may be used to drop the scale to 0-99 so only 2 displays are necessary. In the raw analog mode, the seven segment display shows 00-FF (8 bits hexadecimal) One count = VCC/256 volts. The serial output in raw mode ranges from 000-FFF (12 bits hexadecimal.) One count = VCC/4096 volts. SOUTSOUT- is the serial output of the IC to optionally connect to your UART, a RS-232 driver, a USB IC or Ethernet. The IC outputs three ASCII formatted numbers, followed by a carriage return. (0D hex) The output format is 9600 BPS, 8 bits 1 stop, no parity. Data is sent about every 250 mS. SEGRA, SEGRB, SEGRC, SEGRD, SEGRE, SEGRF, SEGRG SEGLA, SEGLB, SEGLC, SEGLD, SEGLE, SEGLF, SEGLG SEG3B, SEG3C, SEG3G SEG3 is the optional 100’s and minus display SEGR is the right hand of the two displays. SEGL is the left hand of the two displays If the POL pin is open or hi, this SEG outputs will be high when a segment is on. If the POL pin is low or grounded, the SEG outputs will be low when a segment is on. These are the seven segment outputs to each individual display An external driver or current limiting resistor is required for each segment. If you are using only a resistor, it must be sized to limit source current to 5 mA maximum per pin or sink current to 9 mA per pin. See also the segment table, and the ASCII to seven segment translation table. VSS Connect to system ground. VDD Connect to supply voltage of 3.3 to 5 volts. A .1 uF decoupling capacitor to ground is recommended. NOTES: Make no connection to the NC pins. Pins 9 and 19 must be left unconnected. Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 6 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Segment Identification Table Seven Segment Translation Table Protecting the TEMP Input From Voltages Outside 0-VCC VCC INPUT TO TEMP INPUT Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 7 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Using Drivers For Brighter Displays ULN2804 9 2 3 4 5 6 7 8 TMP7 SEG3G SEG3C SEG3B 10 5 2 GND IN2 IN3 IN4 IN5 IN6 IN7 IN8 VCC COM OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 OUT8 10 17 16 15 14 13 12 11 COM B G G C B VCC VCC ULN2804 28 19 9 VDD NC NC VCC 25 SOUT- 10K 24 SEGLG SEGLF SEGLE SEGLD SEGLC SEGLB SEGLA 9 2 3 4 5 6 7 8 23 6 22 7 21 8 20 TEMP 4 3 1 26 27 14 MAXMINFARH SCALE POL VSS COM OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 OUT8 10 17 16 15 14 13 12 11 ULN2804 10K NTC t GND IN2 IN3 IN4 IN5 IN6 IN7 IN8 SEGRG SEGRF SEGRE SEGRD SEGRC SEGRB SEGRA 9 2 3 4 5 6 7 8 18 11 17 12 16 13 15 GND IN2 IN3 IN4 IN5 IN6 IN7 IN8 10 17 16 15 14 13 12 11 C LEFT COMMON ANODE DISPLAY VCC G F E D C B A VCC COM OUT2 OUT3 OUT4 OUT5 OUT6 OUT7 OUT8 OPTIONAL 3RD COMMON ANODE DISPLAY VCC A COM F B G E C D RIGHT COMMON ANODE DISPLAY G F E D C B A VCC A COM F B G E C D Absolute Maximum Ratings Symbol Description Tstg Ta Storage Temperature Operating Temperature V dd V io Imio ESD V dd - V ss Voltage Input Voltage Maximum current into any pin LU Latch up current Electrostatic Discharge Voltage Min Typical Max Units 25 +100 +85 ºC ºC -0.5 +6.0 Vss - 0.5 -25 V dd +0.5 +50 V V mA -55 -40 2000 V 200 Notes Human Body Model ESD mA Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 8 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 DC Electrical Characteristics Symbol Description V dd Idd V oh Supply Voltage Supply Current High Output Level V ol V ih V il Low Output Voltage Input High Level Input Low Level Ioh Iol Cio High Level Source Current Low Level Sink Current Capacitive load Iil Rpu Input leakage Pull Up Resistors On Inputs Min Typical 3.3 Max Units 5.25 V mA V 20 V dd - 1.0 0.75 Note 1 Note 2 Note 3 0.8 V V V mA mA pF Note 2 Note 3 3.5 10 25 10 1 5.6 8 nA k? 2.1 4 Notes Note 1: Vdd=5VDC, all inputs and outputs open Note 2 Ioh=10 mA max per pin, 80 mA maximum all pins combined Note 3 Iol=25 mA max per pin 150 mA maximum all pins combined Theory Of Operation The TMP7 IC is a custom programmed microprocessor designed to monitor the analog voltage on the TEMP input with a 12 bit A/D. The input is read 16 times and averaged. The value read is converted to the desired scale and displayed on seven segment displays and sent to the serial output. Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 9 of 10 Turning Ideas Into Reality ABCircuits www.abcircuits.com POB 123 New Hill NC 27562 (919) 290-7104 Physical Dimensions SOIC-28 Physical Dimensions 28 Pin Dip Package (-DIP Suffix) Close but not quite? Our products are software based, we can modify existing parts to fit your needs at a minimal cost or create new parts designed to your specifications. Email us and we can make a chip for you! For the latest version of this spec sheet, visit www.abcircuits.com Design Services Available We can quickly turn your idea into a chip, a pc board, or a finished product. Contact us with your needs and specifications. Part Number TMP7 Copyright © 2014 ABCircuits. Revised September 2014 Page 10 of 10