AY vationat Semiconductor LM386 September 1997 Low Voltage Audio Power Amplifier General Description The LM386 is a power amplifier designed for use in low volt- age consumer applications. The gain is internally set to 20 to keep external part count low, but the addition of an extemal resistor and capacitor between pins 1 and 8 will increase the gain to any value up to 200. The inputs are ground referenced while the output is auto- matically biased to one half the supply voltage. The quies- cent power drain is only 24 milliwatts when operating from a 6 volt supply, making the LM386 ideal for battery operation. Features = Battery operation = Minimum extemal parts Wide supply voltage range: Low quiescent current drain: Voltage gains from 20 to 200 Ground reterenced input Self-centering output quiescent voltage Low distortion Available in 8 pin MSOP package 4V-12V or 5V-18V 4mA Applications @ AN-FM radio amplifiers @ Portable tape player amplifiers = Intercoms w TV sound systems @ Line drivers @ Ultrasonic drivers w Small servo drivers w Power converters Equivalent Schematic and Connection > < 15k s s gsr GAIN GAIN j B 1 Diagrams Small Outline, OVs Molded Mini Small Outline, and Dual-In-Line Packages tC 1 Ne 4 4 GAIN P GAIN INPUT 4 = BYPASS 5 #O Wout sinrur = L Va, GND J Eo Your DSooss75-2 Top View Order Number LM386M-1, LM386MM-1, LM386N-1, LM386N-3 or LM386N-4 See NS Package Number MosA, MUAOSA or NOSE 1997 National Semiconductor Corporation Dsooss76 www.national.com salyyduiy 1am0dg olpny abeyjop MO] 98eITAbsolute Maximum Ratings oie 2) Dual-In-Line Package Package Dissipation (Note 3) It Military/Aerospace specified devices are required, Soldering (10 sec} +260C please contact the National Semiconductor Sales Office/ Small Gutline Package Distributors for availability and specifications. (SOIC and MSOP} Supply Voltage Vapor Phase (60 sec) 4215C (LM386N-1, -3, LM386M-1) 15V Infrared (15 sec) 4+220C Supply Voltage (LM386N-4) poy See AN-450 Surface Mounting Methods and Their Effect on Preduct Reliability for other methods of soldering surface mount devices. (LM386N) 1.25W Thermal Resistance (LM386M) 0.73W 8y (DIP) 37CWV (LM386MN-1) o.595W 81, (DIP) 107CAV Input Voltage +0.4V 8c (SO Package) 35CAV Storage Temperature -65C to +150C 8,, (SO Package) 172C W Operating Temperature 0G to +70C 8), (MSOP) 210C /W Junction Temperature +150C 8c (MSOP} 56C/W Soldering Information Electrical Characteristics(Notes 1, 2) Ta = 25C Parameter Conditions Min Typ Max Units Operating Supply Voltage (Vs) LM386N-1, -3, LM386M-1, LM386MM-1 4 12 Vv LM386N-4 5 18 Vv Quiescent Current {Iq) Vg =6V,Viy=0 4 8 mA Output Power (Pout) LM386N-1, LM386M-1, LM386MM-1 Vg = 6V, RL = 8&, THD = 10% 250 325 mw LM386N-3 Vg =9V, RL = 8&, THD = 10% 500 700 mw LM386N-4 Ve = 16V, RL = 320, THD = 10% 700 1000 mW Voltage Gain (Ay) Ve = 6V,f=1 kHz 26 dB 10 YF from Pin 1 to 8 46 dB Bandwidth (BW) Vg = 6V, Pins 1 and 8 Open 300 kHz Total Harmonic Distortion (THD) Vg = 6V, RL = 88, Poy = 125 mW 0.2 % f = 1 kHz, Pins 1 and 8 Open Power Supply Rejection Ratio (PSRR) Ve = 6V,f = 1 kHz, Coypass = 10 WF 50 dB Pins 1 and 8 Open, Referred to Output Input Resistance (R,,) 50 kQ Input Bias Current (eis) Vg = 6V, Pins 2 and 3 Open 250 nA Note 1: All voltages are measured with respect to the ground pin. unless ctherwise specitied Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate cencitions for which the device is func- tional, but do not quarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guar- antee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is given, however, the typical value is a goed indication of cevice perlormance Note 3: For operation in ambient temperatures above 25C. the device must be derated based on a 150C maximum junction temperature and 1} a thermal resis- tance of 80CAW junction to ambient for the qual-in-in package and 2) a4 thermal resistance of 170CAW for the small outline package www.national.comApplication Hints GAIN CONTROL To make the LM386 a more versatile amplifier, two pins (1 and 8) are provided for gain control. With pins 1 and 8 open the 1.35 kQ resistor sets the gain at 20 (26 dB). If a capacitor is put from pin 1 to 8, bypassing the 1.35 kQ resistor, the gain will go up to 200 (46 dB). If a resistor is placed in series with the capacitor, the gain can be set to any value from 20 to 200. Gain control can also be done by capacitively cou- pling a resistor for FET) from pin 1 to ground. Additional extemal components can be placed in parallel with the internal feedback resistors to tailor the gain and fre- quency response for individual applications. For example, we can compensate poor speaker bass response by fre- quency shaping the feedback path. This is done with a series RC from pin 1 to 5 (paralleling the internal 15 k resistor). For 6 dB effective bass boost: R = 15 kQ, the lowest value for good stable operation is R = 10 k& if pin 8 is open. If pins 1 and & are bypassed then R as low as 2 kO can be used. This restriction is because the amplifier is only compensated for closed-loop gains greater than 9. INPUT BIASING The schematic shows that both inputs are biased to ground with a 50 kQ resistor. The base current of the input transis- tors is about 250 nA, so the inputs are at about 12.5 mV when lett open. If the dc source resistance driving the LM386 is higher than 250 k& it will contribute very litle additional offset (about 2.5 mV at the input, 50 mV at the output). If the de source resistance is less than 10 k, then shorting the unused input to ground will keep the offset low (about 2.5 mV at the input, 50 m at the output). For de source resistances between these values we can eliminate excess offset by put- ting a resistor from the unused input to ground, equal in value to the de source resistance. Of course all offset prob- lems are eliminated if the input is capacitively coupled. When using the LM386 with higher gains (bypassing the 1.35 kQ resistor between pins 1 and 8) it is necessary to by- pass the unused input, preventing degradation of gain and possible instabilities. This is done with a 0.1 WF capacitor or a short to ground depending on the de source resistance on the driven input. www.national.comTypical Performance Characteristics Quiescent Supply Current vs Supply Voltage 6 SUPPLY CURRENT (mA} 4 5 6 7 B 9 W 11 12 SUPPLY VOLTAGE (VOLTS) DSOoBS7E-5 Voltage Gain vs Frequency 6d $0 40 a0 20 WOLTAGE GAIN (dB) ty o 100 1k 10k 100% IM FREQUENCY (Hz) DSoo 887 614 Device Dissipation vs Output Power 4 Load 2.0 18 15 14 12 10 Oo O6 od Oz DEVICE DISSIPATION (Wi) 4 ol Oz 03 aa 05 OUTPUT POWER (wi DSoope76-17 Power Supply Rejection Ratio (Referred to the Output) vs Frequency 60 , TT OI z tee wy i 40 i | 1 = mu = = 2 = = Ww b TT 1 160 1k 10k 10k FREQUENCY {Ha} DSoone75-12 Distortion vs Frequency 20 Maa 4.8 OF pga - 125 mv 14 | Ay = 26dB 1C, = 0) 12 . 10 na a6 a4 02 TOTAL HARMONIC DISTORTION (%} a 200 50 100 200 S00 th 2k Sk 10h 20k FREQUENCY (Hz} DScoser6-15 Device Dissipation vs Output Power 8 Load 2.0 18 16 14 12 1.0 o8 06 o4 02 DEVICE DISSIPATION (4) O01 02 0.3 04 05 06 07 0894 10 OUTPUT POWER (} DSoons76-18 Peak-to-Peak Output Voltage Swing vs Supply Voltage QUTPWT VOLTAGE {VOLTS PEAK-TO-PEAK} 4 Ss 6 7 a 9 wo o4 12 SUPPLY VOLTAGE (VOLTS) Dsoos876-13 Distortion vs Output Power 10 Vg = BV R, = Bu t= 1 hHr TOTAL HARMONIC DISTORTION (4) ee ee 0.01 Ot 10 POWER GUT (WATTS) DSoobe76-15 Device Dissipation vs Output Power 162 Load = 2 = > a = DEVICE DISSIPATION {W} S ma <7 OV 0 0.2 0405 0.8 1.0 1.2 14 1.6 1820 DUTPUT POWER (WW) DScosere-19 www.national.comTypical Applications Amplitier with Gain = 20 Minimum Parts Amplifier with Gain = 200 Dg0ons762 Amplifier with Gain = 50 390 Vv v uF z LT 1 250uF q = Sur ELDEMA CFS-2158 PO Yo 3 5 10k u Sp, 3vV-O1SmA = L BYPASS O.01uF = BYPASS O.05uF = O05F tf = = i bscoea7e6 f= 1kHz ~ DSoope75-7 Amplifier with Bass Boost Vo 100 DSoo8s76-5 AA VVv = 4=1 kHz Dsoogs7 Be www.national.comTypical Applications (continued) Frequency Response with Bass Boost 27 24 25 24 24 22 21 20 19 1B 17 VOLTAGE GAIN (dB) 20 50 100 200 500 1k 2k Sk 10k 20k FREQUENCY (Hz) DSooss7 610 AM Radio Power Amplifier C VeQ FROM DETECTOR \o FERRITE BEAD 250,:F __ | NAA Bu 10uF a? i+ SPEAKER TL O.05,F DSo0 ps7 B11 Note 4: Twist Supply lead and supply ground very tightly Note &: Twist speaker lead and ground very tightly Note 6: Ferrite bead in Ferroxcube K5-001-001/3B with 3 turns of wire Note 7: R1C1 band limits input signals Note 8: All components must be spaced very closely to IC. www.national.com 6Physical Dimensions inches (millimeters) unless otherwise noted 0.19 0. ieee sa a 7 5 4 van! 0.244 {5.791 6.148) 5 1.010 yim 0.150 -0.157 0010 0.020 5 454 | 0.0590.069 (0.254 -- 0,508} (4.546 1.758) BY MAX YP ALL LEADS. o.004 4 a 1 {0-102 O14 000d 0.010 ALL LEAD TIPS 0.0160.p50 0.355) ~ 10.4061,z70) we (0.2030.254} TYP ALL LEADS: TYP ALL LEADS SO Package (M) Order Number LM386M-1 NS Package Number Mo8A PL L008 Typ ee (D203; 9.004 9.010 (0-102 0.254} SEATING PLANE 0.014-0.020 pyp (0.354 0.500} bata SEW ty www.national.comPhysical Dimensions inches (millimeters) unless otherwise noted (Continued) [B}-44+ [340.1] -+] 0.11810.004 0.193#0.004 01 aeo ane [4.940.1] . ms (0.040) | 192 " | i | | ! PINT [ | LEE IDENT | i NOTE 2 . 0.016 | | TYP} [a (0.0256) 1 4 [oat] rl "Toesy TP (0,0256)}/TYP [0.65] 0,005 Riga] PP 0.043 005 MAX 3 08) tong] TYP PAO = [GI] .002 [0.05] 0.012 2-004 | . -0.002 Typ 7 9.3 t0-10 0.002-0.008 1, [ a5! [0,06-90,15] JCAL 1 {0.189} [4.8] LAND PATTERN RECOMMENDATION fo.1et0.05] [YP 9.02140,005 d [0.53#0.12] o 6 TYP 9.05 (0.934) 9.0375 | SEATING PLANE [0.86] [0.953] [<> Jo.002 [o.05}@le@ [c] 0.00740.002 Whadga (EV 3} 3-Lead (0.118 Wide) Molded Mini Small Outline Package Order Number LM386MM-1 NS Package Number MUAQ8A www.national.comLM386 Low Voltage Audio Power Amplifier Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 0.373 0.400 (9. 47410.18) | 0.090 (2.266) 0.092 Dia. Bl [7 [I al 0.032 + 0.005 . (2.337) ~~ _ (Data +0.127) iN NO. 4 o iw 0.250 + 0.005 AAD LS BIN NG. TIDENT rd (6.35 40.127) PIN NO. 1 1DENT. urrion? [ t a) azn (al L2] Lt [4] 0.040 grat IN 1.030 i.016) rem] be OPTION 2 MAX 0.039 0.145 -0.200 0.3000.320 (0.762) 0.145 -0.200 (7.628.128) { ree i (9-981) (8.683 5.080) I - i t Mot yA 0430+ 0.0085 j . (ea0et0177 t A 0.125 0.140 t gh? = 5 Se 0.065 (9.175 ~ 3.456) 0.009 0.018 G.123_ (1.851) qpeaae 2.020, 0.003 0.015 ty 3.175) (0.508) (0.229-D.3a) ww | TYP MIN 0.080 NOM 0.018 +0.003 0335 has (0.457 0.076) +1016 0100+ 0.010 (ares * 1) tag) +l ii (2.5400.254) masa ato. 0.080 paso * (1.524) (1.270) NOBE CARY FI Dual-In-Line Package (N) Order Number LM386N-1, LM386N-3 or LM386N-4 NS Package Number NO8E LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE- VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMI- CONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or sys- tems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose fail- ure 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. 2. Acritical component in any component ot a life support device or system whose failure to perform can be rea- sonably expected to cause the failure of the life support device or system, or to affact its safety or etfectivenass. 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