HT1612 Timer with Dialer Interface Features • • • • • • Operating voltage: 1.2V~1.7V Dialing number and conversation time display Conversation timer (Max. to 59 mins and 59 secs) Operation current: 10µA (Typ.) • 32768Hz crystal 8 or 10 digits LCD display driver, 3V, 1/2 bias, 1/3 duty (8 digits hand-held calculator LCD is used for 8 digits application) Built-in dialer interface • • Telephone display interface Instrument display Applications • • Timers LCD display drivers General Description phone call, the HT1612 receives dialing data from the dialer and displays the phone number from left to right on the LCD. However, if there is no dialing action within 10 seconds, it restarts the timer again. By adding a TIMER key, the HT1612 can provide the timer reset/hold functions (refer to functional description for more details). The HT1612 is a CMOS chip designed for dialer interface which drives 8 or 10 digits LCD. Various functions, such as displaying dialing number and conversation time, are provided. It normally shows blanks. The timer is started to tell users how long the conversation time has been taken when answering a telephone call. After hanging up the telephone, it returns to show blanks immediately. Whenever makeing a 1 5th July ’95 HT1612 Block Diagram Pad Assignment Chip size: 136 × 134 (mil)2 * The IC substrate should be connected to VDD in the PCB layout artwork. 2 5th July ’95 HT1612 Pad Coordinates Pad No. X Unit: mil Y Pad No. X Y Pad No. X Y 1 –61.92 41.65 18 –18.66 –60.80 35 61.63 39.46 2 –61.92 33.98 19 4.72 –60.80 36 61.63 47.60 3 –61.92 26.30 20 12.36 –60.80 37 61.63 55.79 4 –61.92 17.85 21 20 –60.80 38 41.78 61.14 5 –61.92 10.95 22 34.98 –60.46 39 33.62 61.14 6 –61.92 3.17 23 50.02 –60.46 40 25.46 61.14 7 –61.92 –4.53 24 61.67 –60.80 41 17.30 61.14 8 –61.92 –12.22 25 61.63 –42.18 42 9.14 61.14 9 –61.92 –19.96 26 61.63 –33.98 43 0.98 61.14 10 –61.92 –27.60 27 61.63 –25.82 44 –7.18 61.14 11 –61.92 –35.26 28 61.63 –17.66 45 –15.34 61.14 12 –61.92 –42.95 29 61.63 –9.50 46 –23.50 61.14 13 –61.92 –52.26 38 61.63 –1.34 47 –31.66 61.14 14 –57.80 –60.80 39 61.63 6.80 48 –39.82 61.14 15 –45.90 –60.80 31 61.63 14.98 49 –47.98 61.14 16 –36.50 –60.80 32 61.63 23.14 50 –56.14 61.14 17 –28.86 –60.80 33 61.63 31.30 Pad Description Pad Name I/O Internal Connection SEG1~SEG30 O CMOS OUT LCD segement signal output pads COM1~COM3 O CMOS OUT LCD common signal output pads HK I CMOS IN Pull-High X2 O OSCILLATOR 32768Hz crystal oscillator output X1 I OSCILLATOR 32768Hz crystal oscillator input T2 I CMOS IN Pull-High Test pad (connected to VSS for production test) T1 I CMOS IN Pull-High Test pad (connected to VSS for production test) INT O NMOS OUT TIMER I CMOS IN Pull-Low Description Hook switch detector input Active low Interrupt output, 8 or 16Hz by mask option Timer reset and start/hold toggle control input pad 3 5th July ’95 HT1612 I/O Internal Connection DI I CMOS IN Pull-High Serial data input pad (connected to the dialer) Data should be valid at the falling edge of SK SK I CMOS IN Pull-High Clock input pad (connected to the dialer) VSS I — VA O CMOS OUT Voltage doubler, connected to the external capacitor VB O CMOS OUT Voltage doubler, connected to the external capacitor VC O CMOS OUT Voltage doubler, connected to the external capacitor VDD I — Positive power supply NC — — No connection Pad Name Description Negative power supply (GND) Approximate internal connection circuit Absolute Maximum Rantings Supply Voltage ............................... –0.3V to 5V Storage Temperature ............... –50°C to 125°C Input Voltage ..................... VSS–0.3 to VDD+0.3 Operating Temperature ............. –20°C to 75°C 4 5th July ’95 HT1612 (FOSC=32768Hz, Ta=25°C) Electrical Characteristics Symbol Test Condition Parameter VDD Condition Min. Typ. Max. Unit VDD Operating Voltage — — 1.2 1.5 1.7 V VIL Input Low Voltage 1.2V~1.7V — VSS — 0.2VDD V VIL Input High Voltage 1.2V~1.7V — 0.8VDD — VDD V ISTB Stand-by Current 1.5V VHK=Floating (or VDD) — 0.1 1 µA IDD Operating Current 1.5V No load — 10 30 µA IOL Output Sink Current of INT 1.5V VO=0.3V 500 1000 — µA TA Data Setup Time 1.5V — 1 — — µs TB Data Hold On Time 1.5V — 2 — — µs TC Inter Digit Time 1.5V — 5 — — µs TDB Debounce Time (HK, TMIER) 1.5V — — 31.25 – ms RHI Pull-High Resistance (HK , DI, SK) 1.5V VIN=0V — 1 — MΩ RLO Pull-Low Resistance (TIMER) 1.5V VTIMER=1.5V — 5 — MΩ FOSC System Frequency 1.5V Crystal=32768Hz — 32768 — Hz 5 5th July ’95 HT1612 Functional Description Operational flow chart 6 5th July ’95 HT1612 About On-Hook & Off-Hook Note: 1. Figure a displays blanks. 2. Figure b illustrates a timer mode caused by Off-Hook; timer is reset and starts to count the conversation time. 3. In Figure c. The dialing data are received and displayed on the LCD from left to right after Off-Hook. When the entry interval is over 10 seconds, it resets the timer and starts to count. 7 5th July ’95 HT1612 TIMER key function In the conversation timer mode, the TIMER key can reset or hold the timer. Data & Timing • Data latch timing • For instrument or µC application The HT1612 is also capable of displaying the BCD data which are generated from instruments or µC system. The corresponding data and timing are shown in Data latch timing. Before the data are transmitted to the HT1612, the HK pin should be pull-low or keeps low always. Then, the HT1612 is ready to receive the data. At the falling edge of the clock the data are shifted to the IC. After the whole data are sent to the HT1612, the SK pin is set low to avoid switching to the timer mode. 8 5th July ’95 HT1612 • For telephone application The HT1612 is designed to display telephone numbers which are derived from the HT92XXX series telephone dialers. The corresponding data are illustrated in the following table. 9 5th July ’95 HT1612 Application Circuits For telephone interfacing ∗ The IC substrate should be connected to VDD in the PCB layout artwork. 10 5th July ’95 HT1612 For instrument or µC use (1.5V supply) ∗ The IC substrate should be connected to VDD in the PCB layout artwork. Note: 1. To drive the SK, DI, and HK pin, an open drain NMOS output structure is recommended. 2. To drive the SK, DI and HK pin with CMOS output structure, a voltage divider is needed (R=4.3K, R1=10K). 11 5th July ’95 HT1612 For insturment or µC use (3V supply) ∗ The IC substrate should be connected to VDD in the PCB layout artwork. Note: 1. To drive the SK, DI, and HK pin, an open drain NMOS output structure is recommended. 2. To drive the SK, DI and HK pin with CMOS output structure, a voltage divider is needed (R=20K, R1=10K). 12 5th July ’95 HT1612 LCD Connection For 8-digit application Segment Electrode Side LCD driving system 1/2 bias, 1/3 duty, 3V. Common Electrode Side 13 5th July ’95 HT1612 LCD Connection For 10-digit application Segment Electrode Side * LCD driving system 1/2 bias, 1/3 duty, 3V. Common Electrode Side 14 5th July ’95