NTE748 Integrated Circuit TV Sound Circuit Description: The NTE748 is an integrated circuit in a 14–Lead DIP type pacjage designed for IF limiting, detection, audio preamplifier and driver for the sound portion of a TV receiver. Features: D Excellent Limiting with 80µV(rms) Input Signal typ D Large Output–Voltage Swing–to 3.5V(rms) typ D High IF Voltage Gain–65dB typ D Zener Power–Supply Regulation Built–in D Short–Circuit Protection D A Coincidence Discriminator that Requires Only One RLC Phase Shift Network D Preamplifier to Drive a Single External–Transistor Class–A Audio Output Stage Absolute Maximum Ratings: (TA = +25°C unless otherwise specified) Power Supply Voltage, V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +16V Input Voltage, Vin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7V(rms) Power Dissipation (Package Limitation), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625mW Derate above +25°C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.0mW/°C Operating Temperature Range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0° to +75°C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –65° to +150°C Electrical Characteristics: (V+ = 12V, TA = +25°C, f = 4.5MHz, Deviation = ±25kHz unless otherwise specified) Parameter Symbol Test Conditions Input Voltage VL –3dB Limiting AM Rejection AMR Vin = 20mVrms, AM = 30%, AMR = 20 log, Note 1 Total Harmonic Distortion Maximum Undistorted Audio Output Voltage (Pin10) THD Min Typ Max Unit – 80 160 µVrms VOFM: f = 4.5MHz, Deviation = ±25kHz, QL = 24 – 45 – dB VOAM: f = 5.5MHz, Deviation = ±50kHz, QL = 30 – 45 – dB – 1.0 – % – 3.5 – Vrms QL = 24, 7.5kHz Deviation, Note 1 Vo(max) Audio Gain Adjusted Externally, Q = 24, Note 1 Electrical Characteristics (Cont’d): (V+ = 12V, TA = +25°C, f = 4.5MHz, Deviation = ±25kHz unless otherwise specified) Parameter Recovered Audio (Pin2) Symbol Test Conditions Min VA f = 4.5MHz, Deviation = ±25kHz, QL = 24, Note 1 Typ 0.35 0.50 Max Unit – Vrms f = 5.5MHz, Deviation = ±50kHz, QL = 30, Note 1 – 0.80 – Vrms Open Loop Gain – 25 – dB Audio Preamplifier AVP IF Voltage Gain AVIF – 65 – dB Parallel Input Resistance Rin – 9.0 – kΩ Parallel Input Capacitance Cin – 6.0 – pF Nominal Zener Voltage VReg IZ = 5mA – 11.6 – V Power Supply Current ID IZ = 5mA – 31 – mA Power Dissipation PD IZ = 5mA – 300 375 mW Note 1. QL is loaded circuit Q. Pin Connection Diagram 14 VCC Bypass 1 Audio Output 2 Bypass 3 13 Quadrature Network 12 Test Point IF Input 4 11 Quadrature Bypass Bypass 5 10 Preamp Output Bypass 6 9 Preamp Input GND 7 8 IF Output 14 8 1 7 .785 (19.95) Max .300 (7.62) .200 (5.08) Max .100 (2.45) .600 (15.24) .099 (2.5) Min