KA8512 COMPANDOR INTRODUCTION 14-DIP-300 Compandor is a composite word of compressor and expander. It is used for maintaining dynamic range and improving of S/N ratio, and generally called as a noise reduction system or automatic gain control system. KA8512 consists of compressor, expander, mic amp, Iimiter, ALC(automatic level control) and mute logic. FEATURES • • • • 14-SOP-225B Operating voltage range : 2 ~ 6V Included ALC circuit Easy gain control to use external component Included mute function ORDERING INFORMATION Device Package KA8512 14-DIP-300 KA8512D 14-SOP-225B Operating Temperature -20°C ~ + 70°C BLOCK DIAGRAM EPI ERC EMUTE CMUTE 2 3 5 6 15K 30K RECTIFIER MUTE LOGIC 10K GAIN CELL G 10K _ VREF 12 4 EO 9 CPI- 8 CPI+ 11 AGIC 13 ALC 51K SUM AMP VREF + CO + VREF + _ LIMITER 30K 125K 3.3K _ _ 125K 24K 30K + MIC AMP 10K 15K GAIN CELL G ALC 15K BIAS CIRCUIT RETIFIER 7 14 1 10 GND VCC VREF CRC KA8512 COMPANDOR PIN CONFIGURATION VR E F 1 14 VC C EPI 2 13 ALC ERC 3 12 CO EO 4 11 AGIC EMUTE 5 10 CRC CMUTE 6 9 CPI- GND 7 8 CPI+ KA8512 PIN DESCRIPTION Pin No Symbol 1 VREF Description It is a voltage reference (VREF=1V) used for supplying a constant voltage to the compressor and expander of compandor. It is SUM AMP input terminal of expander. The voice signal recoverd after 2 EPI the demodulation waveform from the receiver passed through the 2’nd order low pass filter enters this terminal. This terminal is used for converting waveform from the full wave rectifier to 3 ERC DC element at the rectifier block of expander (R X C = 22msec) 4 EO It is an output terminal of expander, which a regenerated voice signal comes out. It is an expander mute terminal of compandor and the final mute block of an expander located next to the receiver terminal. It blocks the data sig- 5 EMUTE nal of MICOM being transmitted to an user, and is connected to the RX mute terminal of MICOM. Expanding is executed if this terminal is high, and expander mute is executed if it is low. KA8512 COMPANDOR PIN DESCRIPTION (Continued) Pin No Symbol Description It is compressor mute terminal of a compandor. Mute block is used to avoid duplication of data transmission from MICOM 6 CMUTE (Between the base and hand set) with the voice signal. It is connected to the TX mute terminal of MICOM. Compressing is executed if the terminal is high, and compressor mute is executed if it is low. 7 GND 8 CPI+ It is ground terminal. It is a MIC AMP non-inverting input terminal of compressor, and is used as an input terminal for voice signal. It is a MIC AMP inverting input terminal of compressor, and is used for 9 CPI- adjusting the negative feedback loop gain. (In application, gain is about 5) This terminal is used for converting waveform from the full wave rectifier 10 CRC to DC element at the rectifier block of compressor. (R X C = 22msec) This terminal is used for bypassing an AC element at the feed-back loop 11 AGIC which comes from the SUM AMP block of compressor. A capacitor should be connected between this terminal and GND. 12 CO It is a compressor output terminal of compandor, and is connected to the modulation input terminal of transmitter. It is a reference voltage input terminal of ALC (Automatic Level Control). ALC circuit may be turned off according to the ALC reference voltage, ma- 13 ALC gnitude of output voltage may be limited if it is used for adjusting THD of output voltage of compressor to less than 3% or to limit the frequency of TX in case the input is higher than a certain level. 14 VCC It is supply voltage terminal. KA8512 COMPANDOR ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Maximum Supply Voltage VCC(MAX) 7 V PD 600 mW Operating Temperature T OPR - 20 ~ + 70 °C Storage Temperature T STG - 55 ~ + 150 °C Power Dissipation Value Unit ELECTRICAL CHARACTERISTICS (VCC = 3V, f = 1KHz, Ta = 25°C, Unless otherwise Specified) Characteristic Symbol Test Conditions Min - Typ Max Unit DC Electrical Characteristics Operating Voltage VCC Operating Current ICC 2.0 - 6.0 V No Signal - 3.6 6.0 mA No Signal 0.9 1.0 1.1 V 240 300 340 mVrms Compressor Part Reference Voltage Standard Output Voltage Gain Difference VREF VO(COMP) VINC = 13mVrms = 0dB ∆ GV1(COMP) VINC = -20dB -0.5 0 +0.5 dB ∆ GV2(COMP) VINC = -40dB -1.5 0.7 0 dB Output Distortion THDCOMP VINC = 0dB - 0.5 1.0 % Mute Attenuation Ratio ATTMUTE VINC = 0dB 60 80 - dB Limiting Voltage VLIM(COMP) VINC = Variable 1.15 1.35 1.5 VP-P VALC = 0.87V 280 325 360 mVrms 110 130 160 mVrms ALC VALCO Expander Part Standard Output Voltage Gain Difference VO(EXP) VINE = 180mVrms = 0dB ∆ GV1(EXP) VINE = -10dB +1.0 +0.5 0 dB ∆ GV2(EXP) VINE = -20dB -1.5 -0.7 0 dB ∆ GV3(EXP) VINE = -30dB -1.5 0 +1.5 dB Output Distortion THDEXP VINE = 0dB - 0.5 1.5 % Mute Attenuation Ratio ATTMUTE VINE = 0dB 60 85 - dB Maximum Output Voltage VOEXP(MAX) VINE = Variable 500 600 - mVrms COMPANDOR KA8512 TEST CIRCUIT 10uF 47K Vcc 14 Bias Circuit 13 2 10K VO (C OM P) 1uF 12 125K 10K 10K VRE F 125K MUTE Limiter 3 2.2uF Rectifier Gain Cell G VRE F _ 15K 0.047uF + 1 33uF VI (E X P ) 22uF 11 30K 15K 15K _ + 2.2uF 10 Rectifier SW1 24K 10K Gain Cell G 5 MUT E V RE F 30K 10K Sum Amp 30K Sum Amp _ + 4 1uF VO(E XP ) 0.47uF 9.1K ALC 9 _ 51K + Mic Amp 6 SW2 8 680 VI(COMP) 0.047uF 3.3K 7 KA8512 COMPANDOR APPLICATION CIRCUIT Vcc R12 2.2K TO TX MODULATION Vcc C14 10uF C13 100nF C11 22uF C12 22uF C10 1uF R13 56K 14 12 13 11 9 10 MIC C9 47nF 8 Rectifier 125K 15K _ + ALC V REF 125K MUTE Gain Cell G 15K 3.3K 51K 10K 30K _ 30K + 24K _ Limiter Bias Circuit Sum Amp 10K Gain Cell G Mic Amp + VREF 30K _ 10K VREF MUTE + Sum Amp Rectifier 15K 1 2 R4 68K C4 33uF R6 68K TR1 R3 300 5 C2 68nF C3 100nF C15 100nF 6 C6 100nF 7 CMUTE (TO MICOM) EMUTE (TO MICOM) R10 R7 1K 100 R8 1K C8 47uF KSC945-G FROM RX OUTPUT R1 68K 4 C5 22uF R5 68K R2 220K C1 68nF 3 R9 150 C7 47uF Vcc