HT7500 Clinical Thermometer Features · Single-chip CMOS construction · Alarm warning for fever · Single 1.5V battery operation · Highest temperature hold · Measurement range: +32.0~+42.0°C · Auto power off after 8 min 40 sec · One-key input switch for ON/OFF (+90.0~+108.0°F) Measurement accuracy: ±0.1°C (±0.2°F) Resolution: 0.1°C (0.1°F) · Displays last time measured temperature · Bonding option for Centigrade/Fahrenheit measure- ment General Description The HT7500 is a CMOS digital clinical thermometer IC for measuring body temperature in Centigrade (°C) or Fahrenheit (°F) mode by its bonding option. It also provides alarm and auto power off functions. The other electronic components are LCD display, thermister, 1.5V battery, ON/OFF switch, buzzer, resistors and capacitors. Block Diagram O S C I O S C O S y s te m O S C T E S T 2 P S W C L F H C o n tro l C ir c u it R F S e n s o r O S C R S C o u n te r a n d C o m p a ra to r P u ls e G e n e ra to r S C V D D P u ls e T a b le V S S L O W C B Z 1 B Z 2 V o lta g e D o u b le r C 5 1 2 C A P V E E C o u n te r , C o m p a ra to r a n d L a tc h L C D D r iv e r C O M 1 ~ 3 S A 1 ~ S D 1 T S 8 1 6 T IM T E S T 1 T V Rev. 1.10 T IM E R 1 November 27, 2001 HT7500 Pad Assignment T IM T E S T 1 T V C 5 1 2 C A P S D 1 V E E S C 3 2 S C 3 R F 3 1 3 0 2 9 2 8 2 7 2 6 2 5 (0 ,0 ) 2 4 S C 2 2 3 S C 1 2 2 S B 3 2 1 S B 2 2 0 S B 1 1 9 S A 3 1 8 S A 2 1 7 S A 1 4 R S V D D 3 2 1 V S S P S W T S 8 1 6 L O W C 3 3 5 6 7 1 4 1 5 C O M 2 1 6 C O M 3 1 3 C O M 1 O S C O C L F H T E S T 2 1 2 B Z 2 1 1 9 B Z 1 1 0 O S C I 8 Chip size: 129 ´ 120 (mil)2 * The IC substrate should be connected to VDD in the PCB layout artwork. Pad Coordinates Unit: mil Pin No. X Y Pin No. X Y 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 -58.61 -58.61 -58.61 -58.61 -58.61 -58.61 -58.61 -57.25 -50.62 -43.99 -37.36 -15.64 -3.19 7.44 26.05 58.48 58.82 18.57 6.16 -1.49 -13.30 -20.95 -33.02 -40.08 -53.63 -53.63 -53.63 -53.63 -53.34 -53.34 -52.66 -52.66 -48.75 -7.14 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 58.82 58.82 58.82 58.82 58.82 58.82 58.82 46.24 38.59 31.96 24.82 7.39 -0.43 -14.28 -23.63 -42.33 0.51 8.24 15.90 23.63 31.28 39.01 46.67 54.06 54.06 54.06 54.06 54.06 53.29 53.29 53.29 53.29 Rev. 1.10 2 November 27, 2001 HT7500 Pad Description Pad No. Pad Name I/O Function 1 LOWC B For the supply voltage detector, open the pin when not in use. 2 VSS ¾ Negative power supply, GND 3 SC B Common point, NMOS open drain 4 RF O Connect reference resistor, PMOS open drain 5 RS O Connect sensor resistor, PMOS open drain 6 VDD ¾ Positive power supply 7 PSW I Pull-low input pin, push switch to turn power on or off 8 TEST2 I Pull-low test pin, for production test, floating LCD displays the real time value, when connected to VDD, LCD displays the highest value. 9 CLFH I Floating for °C, connect to VDD for °F 10 OSCI I For system oscillator in 11 OSCO O For system oscillator out 12 BZ1 O Buzzer output 1 13 BZ2 O Buzzer output 2 14~16 COM1~COM3 O LCD backplane drive, 3-level voltage out 17~19 SA1~SA3 O LCD segment drive 20~22 SB1~SB3 O LCD segment drive 23~25 SC1~SC3 O LCD segment drive 26 SD1 O LCD segment drive 27 VEE O Generate negative voltage (-1.5V) 28 CAP O For negative voltage, NMOS output 29 C512 O For negative voltage, inverter output 30 TV B Test pin for IC 31 TEST1 I Test pin for IC 32 TIM I Test pin for IC 33 TS816 I Test pin for IC Absolute Maximum Ratings Supply voltage...............................................0V to 2.0V Operation Temperature........................-2.0°C to +75°C Input voltage ..............................VSS-0.5V to VDD+0.5V Storage Temperature ..........................-55°C to +125°C Note: These are stress ratings only. Stresses exceeding the range specified under ²Absolute Maximum Ratings² may cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability. Rev. 1.10 3 November 27, 2001 HT7500 Electrical Characteristics Symbol Ta=25°C Test Conditions Parameter VDD Conditions ¾ Min. Typ. Max. Unit 1.3 1.5 1.65 V ¾ 60 100 mA ¾ ¾ 1.0 mA 25.6 32 38.4 kHz VDD Operating Voltage ¾ IDD Operating Current 1.5V ISTB Standby Current 1.5V fOSC Oscillating Frequency 1.5V R°C Temperature Measurement Accuracy at Range 35°C~39°C ¾ ¾ -0.1 ¾ 0.1 °C R°F Temperature Measurement Accuracy at Range 95°F~102°F ¾ ¾ -0.2 ¾ 0.2 °F No load ¾ ROSC=820kW LCD Electrode Pattern A 2 A 1 H 1 F 1 B 2 E 1 C 1 D 1 SA1 SA2 F 3 SA3 E 2 A 4 B 3 G 2 G 1 H 1 A 3 F 2 B 1 B 4 G 3 C 2 E 3 D 2 H 2 SB1 SB2 C 4 C 3 H 3 D 3 SB3 SC1 SC2 SC3 SD1 COM1 F1 A1 B1 F2 A2 B2 F3 A3 B3 A4 COM2 E1 G1 C1 E2 G2 C2 E3 G3 C3 B4 COM3 H1 D1 ¾ ¾ D2 H2 ¾ D3 H3 C4 Note: 1/3 duty, 1/2 bias (LCD uses 3V) Function Description · Power sw: push switch to power on or power off. i. When measurement is over, if the temperature > 37.5°C (or 99.5°F) the buzzer alarms ²beep-beep-beep-beepbeep-beep-² for 4 sec, as follows: · When power on: push the switch, then it will generate a ²beep² sound for 0.125 sec. a. First displays all the segments on for 2 sec. b. After a. as described above, then shows the last time measured temperature for 2 sec. c. After b., shows L °C or °F for 0.75 sec. d. After c., displays the measured temperature, then °C or °F mark will flash at a speed of 1Hz. e. If the temperature is < 32°C (or 90°F), the display shows L °C (or °F). f. If the temperature ³ 42°C (or 108°F the display shows H °C (or °F ). g. The display always shows the higher temperature during the temperature measurement. h. If the measured temperature does not change for more than 16 sec., the measurement is over and the °C (or °F) mark flash stops. Rev. 1.10 B I 0 .1 2 5 S B I 0 .1 2 5 S 0 .1 2 5 S B I 0 .1 2 5 S 0 .1 2 5 S 0 .1 2 5 S 0 .3 7 5 S if the temperature £ 37.5°C (or 99.5°F), the buzzer alarms ²beep-beep-beep-beep-² for 4 sec, as follows: B I 0 .5 S 0 .5 S · j. It will automatically turn the power off when measurement is over for 8 min 40 secretary. 4 November 27, 2001 HT7500 · Reference resistor is the value (sensor in 37.0°C) k. When measurement is over, but if the temperature rises within 8 min 40 sec, the °C (or °F) mark will flash again (repeat from step 2-d), and starts to count 8 min 40 sec again. l. When beep sound is on for 4 sec, the temperature is not measured. Ñ flashes at the speed of 1Hz and the measurement may not be accurate. The low voltage detect: 1.35V ± 0.05V. · During the process of mass production, in order to adjust the reference resistance (RF), let test 2 be floating, the measured temperature will be the actual temperature of the measured environment. It can be up or down, not always the higher one. · When battery voltage is low, the battery mark · When power off: the standby current £ 1mA. · The frequency of the buzzer is 5.3kHz · Bonding option °C or °F · Measurement to 0.1 degree in either °C or °F · Sensor use 503ET Flow Chart P o w e r O n D is p la y A ll S e g m e n t 2 s e c D is p la y L a s t M e a s u r e d T e m p e ra tu re 2 s e c D is p la y L C 0 .7 5 s e c M e a s u re D is p la y L C D is p la y th e H ig h e s t V a lu e D is p la y N o t C h a n g e d fo r O v e r 1 6 s e c N o C N o t F la s h fo r 4 s e c ( C a n 't M e a s u r e ) A la r m Y e s D is p la y H C T e m p e ra tu re R is e s w ith in 8 m in 4 0 s e c N o P o w e r O ff Rev. 1.10 5 November 27, 2001 HT7500 Application Circuits 0 .0 2 2 m F 4 0 0 k W 2 2 0 0 p F R E F 1 .5 V B a tte ry S E N S O R R O S C = 8 2 0 k W L O W C V S S S C R F R S V D D P S W T E S T 2 C L F H C 5 C V S 0 .0 2 2 m F S C 1 ~ 3 S B 1 ~ 3 S A 1 ~ 3 O S C I T o L C D C O M 3 O S C O B u z z e r 1 2 A P E E D 1 C O M 2 B Z 1 C O M 1 B Z 2 0 6 % # Note: Substrate connect to VDD VEE, CAP, and C512 are externally connected to capacitors for stabilizing VEE (=-1.5V). BZ1 and BZ2 are connected to an external buzzer to generate sounds. LOWC is connected to an external resistor for adjusting the detector level of a low voltage detector. Open the pin when not in use. OSCI, OSCO are connected to an external resistor, and form an RC oscillator with a built-in capacitor for SYSTEM clock (=32kHz) RS, RF, SC constitute an alternating RC oscillator, which allows one oscillator, namely RS or RF, active at a time. REF (reference resistor) is a resistor value equal to 503ET, sensor is value in 37.0 °C or 98.6 °F. SENSOR is a thermistor. Rev. 1.10 6 November 27, 2001 HT7500 Holtek Semiconductor Inc. (Headquarters) No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan Tel: 886-3-563-1999 Fax: 886-3-563-1189 http://www.holtek.com.tw Holtek Semiconductor Inc. (Taipei Sales Office) 4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan Tel: 886-2-2655-7070 Fax: 886-2-2655-7373 Fax: 886-2-2655-7383 (International sales hotline) Holtek Semiconductor Inc. (Shanghai Sales Office) 7th Floor, Building 2, No.889, Yi Shan Rd., Shanghai, China 200233 Tel: 021-6485-5560 Fax: 021-6485-0313 http://www.holtek.com.cn Holtek Semiconductor Inc. (Shenzhen Sales Office) 5/F, Unit A, Productivity Building, Cross of Science M 3rd Road and Gaoxin M 2nd Road, Science Park, Nanshan District, Shenzhen, China 518057 Tel: 0755-8616-9908, 8616-9308 Fax: 0755-8616-9533 Holtek Semiconductor Inc. (Beijing Sales Office) Suite 1721, Jinyu Tower, A129 West Xuan Wu Men Street, Xicheng District, Beijing, China 100031 Tel: 010-6641-0030, 6641-7751, 6641-7752 Fax: 010-6641-0125 Holtek Semiconductor Inc. (Chengdu Sales Office) 709, Building 3, Champagne Plaza, No.97 Dongda Street, Chengdu, Sichuan, China 610016 Tel: 028-6653-6590 Fax: 028-6653-6591 Holmate Semiconductor, Inc. (North America Sales Office) 46729 Fremont Blvd., Fremont, CA 94538 Tel: 510-252-9880 Fax: 510-252-9885 http://www.holmate.com Copyright Ó 2001 by HOLTEK SEMICONDUCTOR INC. The information appearing in this Data Sheet is believed to be accurate at the time of publication. However, Holtek assumes no responsibility arising from the use of the specifications described. The applications mentioned herein are used solely for the purpose of illustration and Holtek makes no warranty or representation that such applications will be suitable without further modification, nor recommends the use of its products for application that may present a risk to human life due to malfunction or otherwise. Holtek¢s products are not authorized for use as critical components in life support devices or systems. Holtek reserves the right to alter its products without prior notification. For the most up-to-date information, please visit our web site at http://www.holtek.com.tw. Rev. 1.10 7 November 27, 2001