LM2005 20 Watt Automotive Power Amplifier General Description The LM2005 is a dual high power amplifier, designed to deliver optimum performance and reliability for automotive applications. High current capability (3.5A) enables the device to deliver 10W/channel into 2X (LM2005T-S), or 20W bridged monaural (LM2005T-M) into 4X, with low distortion. Y Y Y Y Y Features Y Y Y Y Y Y Wide supply range (8V–18V) Externally programmable gain With or without bootstrap Low distortion Low noise Connection Diagram Y Y Y Y High peak current capability PO e 20W bridge High voltage protection AC and DC output short circuit protection to ground or across load Thermal protection Inductive load protection Accidental open ground protection Immunity to 40V power supply transients 3§ C/W device dissipation Pin for pin compatible with TDA2005 Typical Application Plastic Package TL/H/5129–1 Order Number LM2005T-S or LM2005T-M See NS Package Number TA11A TL/H/5129 – 2 FIGURE 1. 20W Bridge Amplifier Application and Test Circuit C1995 National Semiconductor Corporation TL/H/5129 RRD-B30M115/Printed in U. S. A. LM2005 20 Watt Automotive Power Amplifier April 1989 LM2005T-M and LM2005T-S Absolute Maximum Ratings Output Current Repetitive (Note 2) Non-Repetitive Power Dissipation Operating Temperature If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications. Operating Supply Voltage 18V DC Supply Voltage (Note 1) 28V Peak Supply Voltage (50 ms) 40V 3.5A 4.5A 30W b 40§ C to a 85§ C Storage Temperature Lead Temp. (Soldering, 10 seconds) b 60§ C to a 150§ C 260§ C LM2005T-M Electrical Characteristics Refer to the bridge application circuit, Figure 1 , Tamb e 25§ C, AV e 50 dB, Rth (heatsink) e 4§ C/W, unless otherwise specified Parameter Test Conditions Supply Voltage Output Offset Voltage (Note 3) (between Pin 8 and 10) Total Quiescent Drain Current Includes Current in Feedback Resistors VS e 14.4V VS e 13.2V RL e 4X RL e 3.2X Output Power d e 10% VS e 14.4V f e 1 kHz RL e 4X RL e 3.2X RL e 3.2X g 20 VS e 13.2V Input Sensitivity 75 70 18 20 17 f e 1 kHz PO e 2W PO e 2W RL e 4X RL e 3.2X Max Units 18 V g 150 g 150 mV mV 150 160 mA mA 20 22 19 f e 1 kHz VS e 14.4V RL e 4X PO e 50 mW to 15W VS e 13.2V RL e 3.2X PO e 50 mW to 13W W W W 1 % 1 % 9 8 Input Resistance f e 1 kHz Low Frequency Roll Off (b3 dB) RL e 3.2X High Frequency Roll Off (b3 dB) RL e 3.2X 20 Closed Loop Voltage Gain f e 1 kHz 45 Total Input Noise Voltage Rg e 10 kX (Note 4) Supply Voltage Rejection Rg e 10 kX C4 e 10 mF fripple e 100 Hz Vripple e 0.5V Efficiency VS e 14.4V PO e 20W PO e 22W VS e 13.2V PO e 19W f e 1 kHz RL e 4X RL e 3.2X f e 1 kHz RL e 3.2X VS e 14.4V VS e 13.2V RL e 4X RL e 3.2V Output Voltage with One Side of the Speaker Shorted to Ground Typ 8 VS e 14.4V VS e 13.2V THD Min mV mV 70 kX 40 Note 1: Internal voltage limit. Shuts down above 20V. Note 2: Internal current limit. Note 3: For LM2005T-M only. Note 4: Bandwidth filter: 22 Hz to 22 kHz. 2 50 3 45 Hz kHz dB 10 mV 55 dB 60 60 % % 58 % 2 V LM2005T-S Electrical Characteristics Refer to the stereo application circuit, Figure 2, Tamb e 25§ C, Gv e 50 dB, Rth (heatsink) e 4§ C/W, unless otherwise specified Parameter Test Conditions Supply Voltage VS e 14.4V VS e 13.2V Total Quiescent Drain Current Includes Current in Feedback Resistors VS e 14.4V VS e 13.2V Output Power (Each Channel) f e 1 kHz VS e 14.4V 6.6 6 d e 10% RL e 4X RL e 3.2X RL e 2X RL e 1.6X RL e 3.2X RL e 1.6X RL e 2X VS e 13.2V VS e 16V Cross Talk (Note 5) f e 1 kHz VS e 14.4V RL PO e 50 mW to 4W VS e 14.4V RL PO e 50 mW to 6W VS e 13.2V RL PO e 50 mW to 3W VS e 13.2V RL PO e 40 mW to 6W VS e 14.4V RL e 4X VO e 4 Vrms Rg e 5 kX Input Resistance 6 7 9 10 6 9 Max V 7.2 6.6 7.8 7.2 V V 65 62 120 120 mA mA 6.5 8 10 11 6.5 10 12 W W W W W W W 0.2 1 % 0.3 1 % 0.2 1 % 0.3 1 % e 2X e 3.2X e 1.6X f e 1 kHz 40 f e 10 kHz 60 dB 40 dB 300 f e 1 kHz PO e 1W RL e 4X RL e 3.2X f e 1 kHz Non-Inverting Input RL e 2X High Frequency Roll Off (b3 dB) RL e 2X Voltage Gain (Open Loop) f e 1 kHz Voltage Gain (Closed Loop) f e 1 kHz mV 6 5.5 70 Inverting Input Low Frequency Roll Off (b3 dB) mV 200 kX 10 kX 50 15 Closed Loop Gain Matching 50 dB 51 dB 5 mV 0.5 Total Input Noise Voltage Rg e 10 kX (Note 6) Supply Voltage Rejection Rg e 10 kX C3 e 10 mF fripple e 100 Hz Vripple e 0.5V Efficiency VS e 14.4V RL e 4X RL e 2X VS e 13.2V RL e 3.2X RL e 1.6X f e 1 kHz PO e 6.5W PO e 10W f e 1 kHz PO e 6.5W PO e 10W Note 6: Bandwidth filter: 22 Hz to 22 kHz. 3 1.5 35 Hz kHz 90 48 Note 5: For LM2005T-S only. Units 18 e 4X Input Saturation Voltage Input Sensitivity Typ 8 Quiescent Output Voltage THD (Each Channel) Min dB 45 dB 70 60 % % 70 60 % % Equivalent Schematic TL/H/5129 – 3 4 External Components (Figure 2) Components 1. R1, R2 R5, R4 Comments Sets voltage gain, Components 5. C4, C5 Comments Bootstrap capacitors, used to increase drive to output stage. RÊ for one channel, R1 RÊ for the other. AV e 1 a R5 Where R’ is the equivalent resistance of R2 in parallel with an internal 10k resistor: 6. C3 Improves power supply rejection. Increasing C3 increases turn-on delay (approximately 2 ms per mF). 7. C2, C6 Inverting input DC decouple. Low frequency pole: AV j 1 a 1 . 2qZ(inverting)C2 Z (inverting) & 10 kX. FL2 e 10k # R2 . R2 a 10k If R2 m 10k, then RÊ e AV j 1 a 8. CC R2 . R1 2. R3 Adjusts output symmetry for maximum power output. 3. RO, CO Works to stabilize internal output stage. Necessary for stability. CO should be ceramic disc or equivalently good high frequency capacitor. 4. C1, C9 Input coupling capacitor. Low frequency pole set by Output coupling capacitor. Isolates pins 10 and 8 from load. Low frequency pole; FL3 e 9. CS 1 . 2qRLCC Power supply filtering. 1 . 2qZ (non-inverting) C1 Decreasing capacitor value will also increase noise. FL1 e Typical Applications (Continued) TL/H/5129 – 4 FIGURE 2. 10W/Channel Stereo Amplifier Application and Test Circuit 5 Typical Performance Characteristics Device Dissipation vs Ambient Temperature Supply Current vs Supply Voltage Output Offset Voltage vs Supply Voltage Power Output vs Supply Voltage Output Swing vs Supply Voltage Total Harmonic Distortion vs Frequency (Dual) Total Harmonic Distortion vs Power Output (Bridge) Total Harmonic Distortion vs Power Output (Dual) Power Supply Rejection Ratio (Referred to the Output) vs Frequency Channel Separation (Referred to the Output) vs Frequency Power Output vs Supply Voltage TL/H/5129 – 5 6 Application Hints supply or less than ground levels. The protection diodes will clamp these transients to a safe VBE above and below the rails. The bridge configuration in Figure 3 is designed for applications requiring minimal printed circuit board area and maximum cost effectiveness. The circuit will function with the elimination of bootstrap components R3, C4 and C5 (refer to Figure 1 ). This will result in less output power by decreasing output voltage swing to the load. By using internal feedback resistors (typically 10 kX), feedback components R2, R3 and C2 (Figure 1 ) may be omitted where closed loop voltage gain accuracy is not critical. The net result is a stable, cost effective circuit that will satisfy many application needs. The high current capability of the LM2005 allows it to continuously endure either AC or DC short circuit of the output with a maximum supply voltage of 16V. This will protect the loudspeaker in a bridge mode, when a DC short of the output occurs on one side of the speaker. The device will prevent the speaker from destruction by reducing the DC across the load (bridge mode) to typically less than 2 VDC(VS e 14.4V, RL e 4X), by an internal current pullback method. The LM2005 can withstand a constant 28 VDC on the supply with no damage (maximum operating voltage is 18V). The device is also protected from load dump or dangerous transients up to 40V for 50 ms (every 1000 ms) on the supply with no damage. Protection diodes protect the device driving inductive loads, during which the load can generate voltages greater than TL/H/5129 – 6 AV e 41.5 dB @ 1 kHz FIGURE 3. Minimal Component Application Circuit Component Side (Scale 2:1) TL/H/5129 – 7 FIGURE 4. Printed Circuit Board Layout for LM2005 7 LM2005 20 Watt Automotive Power Amplifier Physical Dimensions inches (millimeters) Lit. Ý 107847 11-Lead TO-220 Power Package (T) Order Number LM2005T-S or LM2005T-M NS Package Number T11A 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 1111 West Bardin Road Arlington, TX 76017 Tel: 1(800) 272-9959 Fax: 1(800) 737-7018 2. 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