NTE1287 Integrated Circuit Linear, Audio Power Amp, 20 Watt Includes Thermal Shutdown Description: The NTE1287 is a monolithic integrated operational amplifier in a 14−lead quad in−line plastic package, intended for use as a low frequency class B power amplifier. Typically it provides 20W output power (d = 1%) at ±18V/4Ω; the guaranteed output power at ±17V/4Ω is 15W. The NTE1287 provides high output current (up to 3.5A) and has very low harmonic and cross−over distortion. Further, the device incorporates an original (and patented) short circuit protection system, comprising an arrangement for automatically limiting the dissipated power so as to keep to working point of the output transistors within their safe operating area. A conventional thermal shut−down system is also included. Absolute Maximum Ratings: Supply Voltage, VS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±22V Input Voltage, Vi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vs Differential Input Voltage, Vi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±15V Output Peak Current (internally limited), IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5A Power Dissipation (TC ≤ +75°C), Ptot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25W Junction Temperature Range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40° to +150°C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −40° to +150°C Thermal Resistance, Junction−to−Case, RthJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +3°C/W Typical Thermal Shut−Down Temperature, Tsd Junction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +140°C Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +105°C Electrical Characteristics: (VS = ±17V, TA = +25°C unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit ±5 − ±22 V − 60 − mA Supply Voltage VS Quiescent Drain Current Id Input Bias Current Ib − 0.15 − µA Input Offset Voltage Vos − 5 − mV Input Offset Current Ios − 0.05 − µA Output Offset Voltage Vos − 10 100 mV Output Power PO VS = ±17V 15.0 18.5 − W VS = ±18V − 20.0 − W Vs = ±22V THD = 1%, GV = 30dB, 30dB f = 40Hz to 15kHz, TC ≤ +70°C RL = 4Ω RL = 8Ω − 16.5 − W THD = 10%, GV = 30dB, 30dB f = 1kHz TC ≤ +70°C RL = 4Ω, VS = ±17V − 24 − W RL = 8Ω, VS = ±18V − 20 − W Electrical Characteristics (Cont’d): (VS = ±17V, TA = +25°C unless otherwise specified) Parameter Input Sensitivity Symbol VI Frequency Response (−3dB) Total Harminic Distortion RL = 4Ω, C4 = 68pF THD PO = 150mW to 15W, RL = 4Ω, 4Ω GV = 30dB, 30dB TC ≤ +70°C RI Voltage Gain GV Input Noise Voltage eN Input Noise Current IN Drain Current GV = 30dB, f = 1kHz, PO = 15W b Input Resistance (Pin7) Supply Voltage Rejection Test Conditions SVR Id Min Typ Max Unit RL = 4Ω, VS = ±17V − 260 − mV RL = 8Ω, VS = ±18V − 380 − mV 10 to 160k Hz f = 1kHz − 0.2 − % f = 40Hz to 15kHz − 0.3 1.0 % f = 1kHz PO = 150mW to 15W, RL = 8Ω, 8Ω GV = 30dB, 30dB VS = ±18V, TC ≤ +70°C f = 40Hz to 15kHz − 0.1 − % − 0.25 − % − 5 − MΩ Open Loop − 100 − dB Closed Loop 29.5 30.0 30.5 dB − 4 − µV − 0.1 − nA RL = 4Ω, GV = 30dB, fripple = 100Hz − 50 − dB PO = 18.5W, RL = 4Ω, − 1 − A PO = 16.5W, VS = ±18V, RL = 8Ω, − 0.7 − A RL = 4Ω, f = 1kHz RL = 4Ω, b (−3dB) = 10Hz to 20kHz Pin Connection Diagram (+) VCC 1 N.C. 2 (−) VCC 3 N.C. 4 (−) VCC 5 14 Output 13 N.C. 12 Power Limiting 11 N.C. 10 Compensation N.C. 6 9 Compensation Non−Inverting Input 7 8 Inverting Input 14 8 1 7 .260 (6.6) Max .770 (19.5) Max .300 (7.62) .200 (5.08) Max .100 (2.54) Max .100 (2.54) .025 (0.64) .600 (15.24) .200 (5.08) .400 (10.16)