KA8504 SPEECH NETWORK WITH DIALER INTERFACE INTRODUCTION 16-DIP-300A The KA8504 is a telephone speech network which includes TX Amp, RX Amp and DTMF Amp. The gain is controlled automatically by sensing the line current. The circuit internally performs electronic switching between dialing and speech by mute signal. FEATURES • Low line current operation • Mute function • DTMF signal interface • Easy gain control ORDERING INFORMATION Device Package Operating Temperature KA8504 16-DIP-300A - 40°C ~ + 85°C BLOCK DIAGRAM ROF 14 RXI 13 1 RX OUTPUT AMP GAIN CONTROLLER GC 12 VL RX GAIN CONTROL RX INPUT AMP TX GAIN CONTROL TX AMP 15 RXO 5 MF 10 MIC+ 11 MIC- TX AMP 2 3 6 9 CI CO MUTE TOF Fig. 1 KA8504 SPEECH NETWORK WITH DIALER INTERFACE PIN CONFIGURATION VL 1 16 Vcc CI 2 15 RXO CO 3 14 ROF BIAS 4 13 RXI MF 5 12 GC MUTE 6 11 MIC- VR 7 10 MIC+ GND 8 9 TOF Fig. 2 PIN DESCRIPTION Pin No Symbol Description 1 VL Positive power line and TX Amp Output. 2 CI Current input. 3 CO 4 BIAS Current output. If the line current is large, this pin dissipates excess power (current) AC signal reference voltage terminal. DTMF input. 5 MF 6 MUTE 7 VR 8 GND 9 TOF 10 MIC + Non inverting Mic input. 11 MIC - Inverting Mic input. 12 GC Gain triggering point regulation. 13 RXI Receiver input. 14 ROF RX out and negative feedback to RX input. 15 RXO Receiver Amp out. 16 VCC Internal power supply pin. Power is supplied from VL through resistor. When the mute pin is “H” level, this pin become active. Mute input. When this pin is 'H’level, speech circuit is muted and the DTMF input is enabled. The voltage of this part becomes reference voltage of internal Amp. Negative power line. Output of the Mic Amp. Negative feedback to MIC -. KA8504 SPEECH NETWORK WITH DIALER INTERFACE ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Value Unit Line Voltage VL 15 V Line Current IL 150 mA IL (SURGE) 200 mA PD 1.0 W Operating Temperature T OPR - 40 ~ 85 °C Storage Temperature T STG - 55 ~ 150 °C Surge Line Current (2 sec) Power Dissipation ELECTRICAL CHARACTERISTICS (Ta = 25°C, f = 1KHz, unless otherwise noted) Characteristic Line Voltage Internal Operating Voltage T X Gain Symbol VL VCC GV (TX) Test Conditions T X Dynamic Output Voltage 3.5 5.4 6.0 6.4 IL = 120mA 10.5 11.5 12.5 IL = 20mA 1.7 2.0 2.3 IL = 50mA 3.3 3.7 4.1 IL = 120mA 7.2 7.6 8.0 IL = 20mA 35.0 37.0 39.0 IL = 120mA 32.0 34.0 36.0 2.5 - - 4.0 - - IL = 20mA -7.5 -4.5 -1.5 IL = 120mA -13.5 -1.5 -7.5 250 - - 300 - - THD = 4.0% IL = 20mA RX Dynamic Output Voltage VO (RX) THD = 10% IL = 120mA THD = 10% RX Output Current DTMF Gain IO (RX) GV (MF) DTMF Input Impedance ZI (MF) Mute Pin High Voltage VIH (MUTE) 3.9 3.1 IL = 120mA GV (RX) Max IL = 20mA THD = 4.0% RX Gain Typ IL = 50mA IL = 20mA VO (TX) Min IL = 20 ~ 120mA Unit V V dB Vp-p dB mVp-p 4.0 - - IL = 20mA 20.5 22.5 24.5 IL = 120mA 17.5 19.5 21.5 mA dB IL = 50mA 24 - - KΩ IL = 20 ~ 120mA 1.5 - VCC V 220 µF + Fig.3 1µF 104 VM 20K + + 100K VMF SWm 5 11 6 9 SPEAKER (IMPEDANCE = 150 Ω) 22 µF 104 7 10 100K 330 8 22µF + KA8504 16 3 13 330 Ω 15 14 22K 1500pF 620Ω 15Ω 2 1 150Ω 43 Ω 334 2.2K 6.2K 11K 1.5K 1.4V 103 + - RING TIP KA8504 SPEECH NETWORK WITH DIALER INTERFACE APPLICATION CIRCUIT