LM2877 Dual 4W Audio Power Amplifier General Description The LM2877 is a monolithic dual power amplifier designed to deliver 4W/channel continuous into 8X loads. The LM2877 is designed to operate with a low number of external components, and still provide flexibility for use in stereo phonographs, tape recorders and AM-FM stereo receivers, etc. Each power amplifier is biased from a common internal regulator to provide high power supply rejection and output Q point centering. The LM2877 is internally compensated for all gains greater than 10, and comes in an 11-lead single-in-line package. Y Y Y Y Y Applications Y Y Y Features Y Y Y Y Y 4W/channel b 68 dB ripple rejection, output referred b 70 dB channel separation, output referred Wide supply range, 6-24V Very low cross-over distortion Low audio band noise AC short circuit protected Internal thermal shutdown Y Y Multi-channel audio systems Stereo phonographs Tape recorders and players AM-FM radio receivers Servo amplifiers Intercom systems Automotive products Connection Diagram (Single-In-Line Package) TL/H/7933 – 1 Top View Order Number LM2877P See NS Package Number P11A *Pin 6 must be connected to GND. C1995 National Semiconductor Corporation TL/H/7933 RRD-B30M75/Printed in U. S. A. LM2877 Dual 4W Audio Power Amplifier February 1995 Absolute Maximum Ratings Storage Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Supply Voltage Input Voltage 26V g 0.7V 0§ C to a 70§ C Operating Temperature b 65§ C to a 150§ C Junction Temperature 150§ C Lead Temperature (Soldering, 10 sec.) Thermal Resistance iJC iJA 260§ C 10§ C/W 55§ C/W Electrical Characteristics VS e 20V, TTAB e 25§ C, RL e 8X, AV e 50 (34 dB) unless otherwise specified. Parameter Total Supply Current Conditions Min PO e 0W Operating Supply Voltage Output Power/Channel Distortion, THD Max Units 25 50 mA 24 V 6 f e 1 kHz, THD e 10%, TTAB e 25§ C VS e 20V VS e 18V VS e 12V, RL e 4X VS e 12V, RL e 8X 4.0 1.5 f e 1 kHz, VS e 20V PO e 50 mW/Channel PO e 1W/Channel PO e 2W/Channel f e 1 kHz, VS e 12V, RL e 4X PO e 50 mW/Channel PO e 500 mW/Channel PO e 1W/Channel Output Swing RL e 8X Channel Separation CF e 50 mF, CIN e 0.1 mF, f e 1 kHz, Output Referred VS e 20V, VO e 4 Vrms VS e 7V, VO e 0.5 Vrms PSRR Power Supply CF e 50 mF, CIN e 0.1 mF, f e 120 Hz Rejection Ratio Output Referred VS e 20V, VRIPPLE e 1 Vrms VS e 7V, VRIPPLE e 0.5 Vrms Noise Typ 4.5 3.6 1.9 1.0 0.1 0.07 0.07 0.25 0.20 0.15 W W W W 1 1 % % % % % % VSb4 Vp-p b 50 b 70 b 60 dB dB b 50 b 68 b 40 dB dB Equivalent Input Noise RS e 0, CIN e 0.1 mF, BW e 20 Hz – 20 kHz Output Noise Wideband RS e 0, CIN e 0.1 mF, AV e 200 2.5 mV 0.80 mV RS e 0, f e 1 kHz, RL e 8X 70 dB Input Offset Voltage 15 mV Input Bias Current 50 nA 4 MX Open Loop Gain Input Impedance Open Loop DC Output Level VS e 20V 9 10 11 V Slew Rate 2.0 V/ms Power Bandwidth 65 kHz Current Limit 1.0 A Note 1: For operation at ambient temperature greater than 25§ C, the LM2877 must be derated based on a maximum 150§ C junction temperature using a thermal resistance which depends upon device mounting techniques. 2 TL/H/7933 – 2 Equivalent Schematic Diagram 3 Typical Performance Characteristics Device Dissipation vs Ambient Temperature Power Supply Rejection Ratio (Referred to the Output) vs Frequency Power Supply Rejection Ratio (Referred to the Output) vs Frequency Power Supply Rejection Ratio (Referred to the Output) vs Supply Voltage Channel Separation (Referred) to the Output) vs Frequency Channel Separation (Referred) to the Output) vs Frequency Average Supply Current vs Power Output Total Harmonic Distortion vs Frequency Total Harmonic Distortion vs Frequency Power Dissipation vs Power Output Open Loop Gain vs Frequency Output Swing vs Supply Voltage TL/H/7933 – 3 4 Typical Applications Stereo Phonograph Amplifier with Bass Tone Control TL/H/7933 – 4 Frequency Response of Bass Tone Control TL/H/7933 – 5 5 Typical Applications (Continued) Stereo Amplifier with AV e 200 TL/H/7933 – 6 Non-Inverting Amplifier Using Split Supply TL/H/7933 – 7 6 Typical Applications (Continued) Window Comparator Driving High, Low Lamps TL/H/7933 – 8 Truth Table VIN k (/4 V a (/4 V a to */4 V a l */4 V a High Low Off Off On On Off Off Application Hints The only special care required with the LM2877 is to limit the maximum input differential voltage to g 7V. If this differential voltage is exceeded, the input characteristics may change. The LM2877 is an improved LM377 in typical audio applications. In the LM2877, the internal voltage regulator for the input stage is generated from the voltage on pin 1. Normally, the input common-mode range is within g 0.7V of this pin 1 voltage. Nevertheless, the common-mode range can be increased by externally forcing the voltage on pin 1. One way to do this is to short pin 1 to the positive supply, pin 11. Figure 1 shows a power op amp application with AV e 1. The 100k and 10k resistors set a noise gain of 10 and are dictated by amplifier stability. The 10k resistor is bootstrapped by the feedback so the input resistance is dominated by the 1 MX resistor. TL/H/7933 – 9 FIGURE 1 7 LM2877 Dual 4W Audio Power Amplifier Physical Dimensions inches (millimeters) Order Number LM2877P See NS Package Number P11A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation 2900 Semiconductor Drive P.O. Box 58090 Santa Clara, CA 95052-8090 Tel: 1(800) 272-9959 TWX: (910) 339-9240 National Semiconductor GmbH Livry-Gargan-Str. 10 D-82256 F4urstenfeldbruck Germany Tel: (81-41) 35-0 Telex: 527649 Fax: (81-41) 35-1 National Semiconductor Japan Ltd. Sumitomo Chemical Engineering Center Bldg. 7F 1-7-1, Nakase, Mihama-Ku Chiba-City, Ciba Prefecture 261 Tel: (043) 299-2300 Fax: (043) 299-2500 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. National Semiconductor Hong Kong Ltd. 13th Floor, Straight Block, Ocean Centre, 5 Canton Rd. Tsimshatsui, Kowloon Hong Kong Tel: (852) 2737-1600 Fax: (852) 2736-9960 National Semiconductores Do Brazil Ltda. Rue Deputado Lacorda Franco 120-3A Sao Paulo-SP Brazil 05418-000 Tel: (55-11) 212-5066 Telex: 391-1131931 NSBR BR Fax: (55-11) 212-1181 National Semiconductor (Australia) Pty, Ltd. Building 16 Business Park Drive Monash Business Park Nottinghill, Melbourne Victoria 3168 Australia Tel: (3) 558-9999 Fax: (3) 558-9998 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.