LM2877

LM2877 Dual 4W Audio Power Amplifier February 1995 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 Wide supply range 6-24V Very low cross-over distortion Low audio band noise AC short circuit protected Internal thermal shutdown Applications Y Y Y Features Y Y Y Y Y Y Y 4W channel b 68 dB ripple rejection output referred b 70 dB channel separation output referred 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 Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage Input Voltage Operating Temperature 26V g 0 7V Storage Temperature Junction Temperature Lead Temperature (Soldering 10 sec ) Thermal Resistance iJC iJA b 65 C to a 150 C 150 C 260 C 10 C W 55 C W 0 C to a 70 C Electrical Characteristics VS e 20V Parameter Total Supply Current Operating Supply Voltage Output Power Channel PO e 0W TTAB e 25 C RL e 8X AV e 50 (34 dB) unless otherwise specified Min Typ 25 6 Max 50 24 45 36 19 10 01 0 07 0 07 0 25 0 20 0 15 VSb4 Units mA V W W W W % % % % % % Vp-p Conditions 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 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 RL e 8X 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 40 15 Distortion THD 1 1 Output Swing Channel Separation b 50 b 70 b 60 dB dB PSRR Power Supply Rejection Ratio CF e 50 mF CIN e 0 1 mF f e 120 Hz Output Referred VS e 20V VRIPPLE e 1 Vrms VS e 7V VRIPPLE e 0 5 Vrms 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 RS e 0 f e 1 kHz RL e 8X b 50 b 68 b 40 dB dB mV mV dB mV nA MX 11 V V ms kHz A Noise 25 0 80 70 15 50 Open Loop Gain Input Offset Voltage Input Bias Current Input Impedance DC Output Level Slew Rate Power Bandwidth Current Limit Open Loop VS e 20V 9 4 10 20 65 10 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 3 TL H 7933 – 2 Equivalent Schematic Diagram 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 High Va Off Off On Low On Off Off Va V a to l Va Application Hints 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 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 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