AG8889 CALL WAITING DECODER I. GENERAL DESCRIPTION This is a new version of Call Waiting service decoder on the telephone. Call Waiting service works by alerting a customer engaged in a telephone call to a new incoming call. This way the customer can still receive important calls while engaged in a current call. The Call Waiting decoder can detect dual tone (2130Hz and 2750Hz) alert signal and generate a valid signal on the data pins for micro controller. II. FEATURES • • • • • • Compatible with Bellcore special report SR-TSV-002476 3.6V ~ 6.0V supply voltage Call-Waiting (2130Hz plus 2750Hz) Alert Signal Detector Good talkdown and talkoff performance Sensitivity compensated by adjusting input OP gain Package series --- 14-pin DIP or 16-pin SOP (150 mil) AG8889AP for 14-pin DIP AG8889N for 16-pin SOP (150 mil) III. APPLICATION • Feature phones • Cordless phones • Adjunct unit (stand alone) IV. PIN CONFIGURATION AG8889AP AG8889N TIP 1 14 VDD RING 2 13 OPO 3 VREF TIP 1 16 VDD DO RING 2 15 DO 12 NC OPO 3 14 NC 4 11 NC VREF 4 13 NC NC 5 10 NC NC 5 12 NC PWD 6 9 OSCI PWD 6 11 OSCI VSS 7 8 OSCO VSS 7 10 OSCO NC 8 9 * This specification are subject to be changed without notice. NC 8.8.2000 1 AG8889 CALL WAITING DECODER V. FUNCTIONAL BLOCK DIAGRAM OPO TIP Tone RING VREF DO Detection Block Filter Vdd/2 Voltage Reference Clock Generator OSCI OSCO PWD VI. PIN DESCRIPTIONS Pin TIP RING OPO VREF PWD I/O I I O OSCI OSCO DO I O O VDD GND NC I Description Tip in should be connected with twisted pair Ring in should be connected with twisted pair Output of OP Amp Reference voltage Vref = 1/2 Vdd This pin is normal low enabling chip on normal operation and ready to detect CAS tone signals. This active high input sets the chip into power down mode and disable oscillator to save power. 3.58MHz oscillator in 3.58MHz oscillator out DO : used as output, this pin determines whether DO signal is valid or not. High is valid. Normal low. Power Ground Non connected VII. FUNCTIONAL DESCRIPTIONS Call Waiting service works by alerting a customer engaged in a telephone call to a new incoming call. This way the customer can still receive important calls while engaged in a current call. The CALL WAITING DECODER can detect CAS(Call-Waiting Alerting Signal 2130Hz plus 2750Hz) and generate a valid signal on the data pin. The call waiting decoder is designed to support the Caller Number Deliver feature, which is offered by regional Bell Operating Companies. The call waiting decoder has three blocks, including differential amplifier, tone filter detection block In a typical application, this IC receives Tip and Ring signals from twisted pairs. The signals as inputs of differential amplifier, and the differential amplifier sends input signal to a band pass tone filter. Once the signal is filtered, the digital detection block decodes the information. The output data made available at DO pin. This IC is used for detecting CAS signals. Once the signal is detected, the detection indication is shown on the data output DO pin. The DO pin is normal low. When this IC detects 2130Hz and 2750Hz frequency at the same time, then DO pin goes to high. * This specification are subject to be changed without notice. 2 8.8.2000 AG8889 CALL WAITING DECODER DC CHARACTERISTIC VDD=5V, Vss=0V, Ta=25°C, fOSC=3.58MHz Sym. VDD Description operating supply voltage IDD VIL operating supply current low level input voltage VIH VOL high level input voltage low level output voltage Condition Min. 3.6 Typ. Max. 6 Unit V 3.3 5 1.5 mA V 3.5 load=1mA VOH high level output voltage load=1mA Note: 1.both tones in the composite signal have equal amplitude. 0.4 V V 4.6 V 2.tone pair is deviated by 0.5%. 3.addes a 0.1uf capacitor between Power and Ground. AC ELECTRICAL CHARACTERISTIC (VDD=+5V,Ta=+25°C) CHARACTERISTIC Input sensitivity TIP and RING pins ,Vdd=+5V, Input G=1 Input frequency tolerance for 2130Hz Input frequency tolerance for 2750Hz * This specification are subject to be changed without notice. Min. Typ. -38 ±1.2 ±1.2 Max. Unit dBm % % 8.8.2000 3 AG8889 CALL WAITING DECODER WAVE FORM TIMING DO timing: line event normal on hook off hook engaged call alert tone (~80ms) Tvd Tinvd Tfinvd CAS Tvd=Tfvd+Tdvd Tinvd=Tfinvd+Tdinvd Tfvd Tdvd Tdinvd OSC timing: power off power on Power on/off PWD Tosc OSC off Tosc OSCI OSC off OSC on (OSCO) Sym. Tfvd Tfinvd Tdvd Tdinvd Tvd Tinvd alert tone Tosc Description filter output signal valid delay filter output signal invalid delay digital delay of valid signal digital delay of invalid signal total delay of valid signal total delay of invalid signal input alert tone length (2130 ,2750 Hz @ -20dBm ) Oscillator enable delay time Min. Typ. 6 6 36 20 42 26 80 Max. Unit ms ms ms ms ms ms ms 10 ms Note: detected alert tone length shown above is assumed that no speech signals input. test under alert tone signal = -22dBm (600Ω) * This specification are subject to be changed without notice. 8.8.2000 4 AG8889 CALL WAITING DECODER APPLICATION CIRCUIT 1 When PWD pin (pin 6) is controlled by MCU or external hook detect circuit, the users can use the following application. (pin6 is connected to control pin of MCU or hook detect output) 5V 5V 3 OPO 0.01u 250V 430k 39k 470k VDD 14 0.1u 47p TIP 1 TIP 39k 2 RING RING 62k 0.01u 250V 430k DO 13 PWD 6 51k 4 VREF OSCI 9 OSCO 7 GND 8 C1 33p Y1 3.58MHz C2 33p Note : Y1 KYOCERA KBR-3.58MSB202 C1 33p C2 33p KBR-3.58MSB202 tolerrance : -0.10% ~+0.15% * This specification are subject to be changed without notice. 8-bit MCU 8.8.2000 5 AG8889 CALL WAITING DECODER APPLICATION CIRCUIT 2 In some application, the call waiting decoder is always powered on , the PWD pin (pin 6) can not be directly connected to the ground, the users have to use the following application. (pin6 is connected with a capacitor to VDD and connected with a resistor to the ground). 5V 5V 3 OPO 0.01u 250V 430k 39k 470k VD 14 D 0.1u 47p TIP 1 TIP 5V 39k 2 RING RING 62k 0.01u 250V 430k 470p DO 13 PWD 6 51k 4 VREF OSCI 9 OSCO 7 GN D 8 C1 33p Y1 3.58MHz C2 33p 20k Note : Y1 KYOCERA KBR-3.58MSB202 C1 33p C2 33p KBR-3.58MSB202 tolerrance : -0.10% ~+0.15% * This specification are subject to be changed without notice. 8-bit MCU 8.8.2000 6 AG8889 CALL WAITING DECODER APPLICATION NOTE 1. VDD, GND To reduce noise effects, separate the analog and digital systems close to the device. For both the digital and analog VDD pins, use a ceramic capacitor of about 0.1uF set as close as possible to the pin to bypass to the respective GND's. 2. PWD pin By connecting PWD pin to GND, normal mode is obtained. In the normal mode, the oscillator is activated then ready to decode CAS signal and the chip consumes operating current. By connecting PWD pin to VDD, the chip is on power down mode and the chip consumes just stand-by current. 3. OPO pin This pin is the gain adjustment of internal OP Amp. 4. XIN, XOUT pins If the resonator is used, two capacitors about 33pF and 1M( resistor have to be connected for frequency accuracy. * This specification are subject to be changed without notice. 8.8.2000 7