Ordering number : ENA1783A LA4708N Monolithic Linear IC 20W 2-channel BTL AF Power Amplifier for Car Stereo http://onsemi.com Overview The LA4708N is a BTL two-channel power IC for car audio developed in pursuit of excellent sound quality. Low-region frequency characteristics have been improved through the use of a new NF capacitor-less circuit, and crosstalk which causes “muddy” sound has been reduced by improving both circuit and pattern layout. As a result, the LA4708N provides powerful bass and clear treble. In addition, the LA4708N features on-chip protectors and standby switch. Features High power : supports total output of 30W 30W (VCC = 13.2V, THD = 30%, RL = 4) Supports RL = 2 (PO = 30W when VCC = 13.2V, THD = 10%) Designed for excellent sound quality (fL 10Hz, fH = 130kHz) NF capacitor-less Any on time settable by external capacitor Less pop noise Standby switch circuit on chip (microprocessor supported) Various protectors on chip (output-to-ground short/output-to-VCC short/load short/overvoltage/thermal shutdown circuit) Specifications Maximum Ratings at Ta = 25C Parameter Symbol Conditions Ratings Unit Maximum supply voltage VCC max 1 No signal, t = 60s Surge supply voltage VCC surge t 0.2s, single giant pulse 50 V Maximum output current IO peak Per channel 4.5 A Allowable power dissipation Pd max Arbitrarily large heat sink Operating temperature Topr 35 to 85 C Storage temperature Tstg 40 to 150 C VCC max 2 24 V 16 V 37.5 W * Set VCC, RL in a range that does not exceed Pd max = 37.5W Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality should not be assumed, damage may occur and reliability may be affected. SIP18H ORDERING INFORMATION See detailed ordering and shipping information on page 9 of this data sheet. Semiconductor Components Industries, LLC, 2014 March, 2014 30314HK/61610SY 20100405-S0010 No.A1783-1/9 LA4708N Operating Conditions at Ta = 25C Parameter Symbol Recommended supply voltage VCC Operating voltage range VCC op Recommended load resistance RL Recommended load resistance range RL op Conditions Ratings Unit 13.2 Range where Pd max is not exceeded V 9 to 16 V 4 2 to 4 Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond the Recommended Operating Ranges limits may affect device reliability. Electrical Characteristics at Ta = 25C, VCC = 13.2V, RL = 4, f = 1kHz, Rg = 600 Parameter Symbol Conditions min typ Unit ICCO Standby current lst Voltage gain VG Total harmonic distortion THD PO = 2W Output power PO1 THD = 10% PO2 THD = 10%, VCC = 14.4V 24 W PO3 THD = 10%, RL = 2 30 W VN offset Rg = 0 Output offset voltage 70 max Quiescent current 38 Output noise voltage VNO Rg = 0, B.P.F. = 20Hz to 20kHz Ripple rejection ratio SVRR Rg = 0, fR = 100Hz, VR = 0dBm Channel separation CHsep Rg = 10k, VO = 0dBm Input resistance ri Standby pin applied voltaga Vst Amp on, applied through 10k 16 150 250 mA 10 60 A 40 42 dB 0.07 0.4 20 300 300 0.1 40 0.5 50 50 60 21 30 2.5 % W mV mVrms dB dB 39 VCC k V Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product performance may not be indicated by the Electrical Characteristics if operated under different conditions. Package Dimensions unit : mm SIP18 36.8x13.8 / SIP18H CASE 127AS ISSUE A GENERIC MARKING DIAGRAM* XXXXXXXXXX YMDDD XXXXX = Specific Device Code Y = Year M = Month DDD = Additional Traceability Data *This information is generic. Please refer to device data sheet for actual part marking. No. A1783-2/9 LA4708N Pd max -- Ta 35 θf = 1.5°C/W 30 θjc = 2.0°C/W 2.0°C/W 25 3.2°C/W 20 4.1°C/W 15 7.0°C/W 10 No Fin 5 3.5 0 -20 0 20 40 60 80 θf -- Sf 3 Arbitrarily large heat sink Heat sink thermal resistance, θf -- °C/ W Allowable power dissipation, Pd max -- W 40 100 120 Ambient temperature, Ta -- °C 140 AI heat sink, t = 1.5mm Tightening torque 39N cm With silicone grease applied 2 10 7 5 3 2 2 160 3 5 7 2 100 3 5 Heat sink area, Sf -- cm2 JK470801 7 1000 JK470802 Block Diagram 100μF/ 16V VCC + C2 VCC1 18 1 3 OUTPUT PIN-TO-VCC SHORT PROTECTOR RIPPLE FILTER POWER PREDRIVER C1 IN1 + 17 + IN - 2 2.2μF/ 6.3V C5 POWER 16 GND1 LOAD SHORT PROTECTOR PREDRIVER POWER + 2200μF INVERTING OUT1 0.1μF ∗∗ C6 R2 2.2Ω R3 2.2Ω ∗∗ 0.1μF C7 + RL 2 to 4Ω 15 NONINVERTING OUT1 PRE GND OFF ON 4 R1 10kΩ 5 BIAS CIRCUIT OVERVOLTAGE/ SURGE PROTECTOR VCC OUTPUT PIN-TO-GND SHORT PROTECTOR THERMAL SHUTDOWN STANDBY SW OUTPUT PIN-TO-GND SHORT PROTECTOR ∗∗ POLYESTER FILM CAPACITOR +5V C4 IN2 + POWER PREDRIVER 14 NONINVERTING OUT2 0.1μF C8 2.2Ω ∗∗ + IN - 7 2.2μF/ 6.3V LOAD SHORT PROTECTOR POWER 13 GND2 R4 2.2Ω 0.1μF C9 R5 ∗∗ PREDRIVER POWER 12 POP NOISE PREVENTION CIRCUIT 6 33μF/ 6.3V + OUTPUT PIN-TO-VCC SHORT PROTECTOR 8 9 10 11 N.C C3 + - RL 2 to 4Ω INVERTING OUT2 VCC2 Pins 1,9 : Don't use. Pin 10 : No connection. Each Pin Voltage VCC = 13.2V, 5V applied through STBY = 10k, RL = 4, Rg = 0 Pin No. 1 Name Pin voltage (V) 0.29 2 3 4 5 6 IN1 DC Pre-GND STBY ON TIME 1.58 6.55 0 3.2 2.28 Pin No. 7 8 9 10 11 12 Name IN2 POP - N.C VCC2 OUT 2 Pin voltage (V) 1.58 2.08 0.29 0 13.2 6.5 Pin No. 13 14 15 16 17 18 Name PWR-GND 2 OUT 2 OUT 1 PWR-GND 1 OUT 1 VCC1 Pin voltage (V) 0 6.5 6.5 0 6.5 13.2 No. A1783-3/9 LA4708N Sample Print Pattern VCC 1 + C5 + C1 IN1 + C6 OUT1 PRE GND C2 R1 R2 GND STB + C7 C3 IN2 C + 4 R3 OUT2 C8 R4 GND Copper foil area 90 × 105mm2 R5 C9 Description of External Components C1, C4 Input capacitors C2 Decoupling capacitor (ripple filter) C3 Amplifier on time setting capacitor C5 Power supply capacitor C6, C7, C8, C9 Oscillation blocking capacitors Use polyester film capacitors (Mylar capacitors) with good temperature characteristics. (R2, R3, R4, and R5 used jointly.) Since stability may be affected slightly by the pattern layout, etc., 0.1F or more is recommended. R1 Standby switch current limiting resistor 10k is recommended (when the applied voltage for the standby switch is 2.5V to 13.2V). This resistor cannot be removed. 2.2F is recommended. fL can be varied by C1, C4 capacitances to adjust the bass range. Approximately 0.8 second for 33F. Since the on time is proportional to this capacitance, it can be set as desired by varying this capacitance. (Refer to the characteristics curve.) No. A1783-4/9 LA4708N Features of IC Inside and Usage Notes Standby function Pin 5 is the standby switch pin. The amplifier is turned on by applying approximately 2.5V or more to this pin through an external resistor (R1). If voltage in excess of 13.2V is to be applied to the standby switch, calculate the value of R1 using the following formula so that the current flowing into pin 5 is 500A or less: R1 = Applied voltage 1.4V 500A 10k Mute function Pin 6 is the connector for the capacitor that determines the on time in order to prevent pop noise. By grounding this pin, the amplifier can implement mute operation. In this case, the recovery time depends on C3. How to reduce pop noise Although the LA4708N reduces pop noise, an electrolytic capacitor of between 0.47 and 2.2F can be connected between pin 8 and the pre-GND to further reduce pop noise that occurs when power supply is turned on/off (standby switch on/off). The larger the capacitance, the lower the frequency of pop noise, and it is barely audible, but sound residue of the sound signal is liable to linger when power is turned off. Pin 8 is the bias pin for the output amplifier and normally is left open. Protectors In an output-to-ground and output-to-VCC short protector system configuration, if a DC resistor is connected between amplifier output pin and GND, the protector may operate, causing the amplifier not to start operating. Therefore, as a general rule, no DC resistor should be connected between amplifier output pin and GND. In order to prevent damage or degradation which may be caused by abnormally heated IC, the LA4708N has a thermal shutdown protector. Accordingly, if the IC junction temperature (Tj) climbs to around 170 to 180C due to inadequate heat dissipation, the thermal shutdown protector will operate to control the output gradually into attenuation. Also be fully careful of handling other protectors built in the LA4708N. Miscellaneous Since pins 1 and 9, which are unused, are connected internally, they must be left open. Pin 10 is an NC pin (no internal connection). No. A1783-5/9 LA4708N ICCO -- VCC 5 RL = Open Rg = 0 VST = 5V 180 160 3 2 Output power, PO -- W 140 120 100 80 60 0 0 4 8 12 16 20 Supply voltage, VCC -- V 24 VCC 2V = 13. 2 1.0 7 5 28 dm ax 60 din Output power, PO -- W gP 50 ee 36 32 28 24 = RL 20 2Ω Ω RL 16 7 =4 2 10 3 5 7 100 2 Input level, VIN -- mVrms PO -- VCC f = 1kHz Rg = 600Ω THD = 10% Dual channel drive 5 JK470806 Ex c Output power, PO -- W 40 V CC 3 0.1 7 5 3 20 44 V 4.4 =1 3 2 40 48 10 7 5 PO -- VIN RL = 4Ω f = 1kHz Rg = 600Ω VG = 40dB Dual channel drive 12 3 5 JK470807 PO -- VCC f = 1kHz Rg = 600Ω THD = 30% Dual channel drive 40 R L= 2Ω Quiescent current, ICCO -- mA 200 30 4Ω = RL 20 10 8 4 6 8 10 12 14 16 Supply voltage, VCC -- V 3 2 10 7 5 3 1.0 7 5 f = 10kH z 100Hz 0.1 7 5 2 3 5 7 1.0 2 3 5 7 10 Output power, PO -- W 2 2 3 14 16 18 2 10 7 5 THD -- PO 3 2 1.0 7 5 f = 10k Hz 3 2 100H z 1kH z 2 3 5 7 1.0 THD -- f 4 2 2 3 5 7 10 Output power, PO -- W JK470810 VCC = 13.2V RL = 4Ω Rg = 600Ω PO = 2W 20 JK470809 VCC = 13.2V RL = 2Ω Rg = 600Ω Dual channel drive 7 5 0.1 5 2 3 5 7 JK470811 f Response VCC = 13.2V RL = 4Ω Rg = 600Ω VO = 0dBm at f = 1kHz 0 1.0 Response -- dB Total harmoinc distortion, THD -- % 3 12 0.1 1kHz 3 0.1 10 Supply voltage, VCC -- V THD -- PO VCC = 13.2V RL = 4Ω Rg = 600Ω Dual channel drive 3 2 8 JK470808 3 2 5 0 6 20 Total harmoinc distortion, THD -- % Total harmoinc distortion, THD -- % 5 18 7 5 3 2 -2 -4 -6 0.1 7 -8 5 3 10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k Input frequency, f -- Hz 2 3 5 7100k JK470812 -10 10 2 3 5 7 100 2 3 5 7 1k 2 3 5 7 10k Input frequency, f -- Hz 2 3 5 7100k JK470813 No. A1783-6/9 LA4708N Channel separation, CHSep -- dB THD = 10% 20 18 3% 1% VCC = 13.2V RL = 4Ω Rg = 600Ω VG = 40dB Dual channel drive 14 12 10 10 2 3 5 7 100 2 3 5 7 1k 2 3 5 710k 2 3 Input frequency, f -- Hz 3 2 0.1 7 5 3 5 7 1k 2 5 7 10k 2 3 5 7 100k -60 1 CH2 CH -80 0 -40 T2 1 OUT -60 -80 The value of power supply capacitor is 0.47μF (Mylar) 2 3 5 7 1k 2 3 5 7 10k 2 3 Ripple frequency, fR -- Hz 2 100 7 C 5 I CC 3 2 = 7 5 (V C 3 2 ) C 10 Pd 6V =1 Pd ( V CC = (V C 1.0 13.2 V) 7 7 5 7 100k JK470815 OUT1 OUT2 -60 -80 2200μF (power supply capacitor) is changed to 0.47μF (Mylar) 6 8 10 12 14 16 18 VCC = 13.2V RL = 4Ω fR = 100Hz/3kHz -40 OUT2 fR = 100Hz OUT1 -60 OUT1 OUT2 fR = 3kHz -80 100 7 20 JK470817 SVRR -- VCCR -20 2 10 ) 2 3 The value of power supply capacitor is 0.47μF (Mylar) VO Calculate as SVRR = 20 log VCCR 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 Power supply ripple voltage, VCCR -- Vrms 2 V 16 5 7 10k -40 -100 0 5 7100k Pd, ICC -- PO 2 3 -20 JK470818 RL = 4Ω Rg = 600Ω f = 1kHz Dual channel drive 5 7 1k RL = 4Ω Rg = 0 fR = 100Hz VCCR = 0dBm 0 OU 5 7 100 2 3 Supply voltage, VCC -- V -20 2 3 5 7 100 SVRR -- VCC -100 4 2 VCC = 13.2V RL = 4Ω Rg = 0 VCCR = 0dBm -100 10 2 3 JK470816 SVRR -- fR 20 Ripple rejection ratio, SVRR -- dB 3 Input resistance, Rg -- Ω CH2 CH1 3 2 2 Power dissipation, Pd -- W -40 0 VCC = 13.2V RL = 4Ω DIN AUDIO Ripple rejection ratio, SVRR -- dB 5 -20 Input frequency, f -- Hz Ripple rejection ratio, SVRR -- dB Output noise voltage, VNO -- mVrms 7 0 -100 10 5 7 VNO -- Rg 1.0 VCC = 13.2V RL = 4Ω Rg = 10kΩ VO = 0dBm JK470814 Current drain, ICC -- A Power dissipation, Pd -- W Output power, PO -- W 22 16 CH Sep -- f 20 2.0 2.2 JK470819 Pd, ICC -- PO 2 RL = 2Ω Rg = 600Ω f = 1kHz Dual channel drive ) 6V Allowable power dissipation package 5 =1 I CC CC (V 10 7 5 Pd max = 37.5W 3 3 ) 6V 2 Pd 10 (V CC Pd (VCC = 13.2V) =1 2 1.0 7 7 5 5 5 5 3 3 3 3 2 7 2 2 7 0.1 2 3 5 7 1.0 2 3 5 7 10 Output power, PO -- W 2 3 5 JK470820 2 3 5 7 0.1 2 3 5 7 1.0 2 3 5 7 10 Output power, PO -- W 2 3 Current drain, ICC -- A PO -- f 24 2 5 7 JK470821 No. A1783-7/9 LA4708N VN -- VCC 12 200 RL = Open Rg = 0 180 Quiescent current, ICCO -- mA Output pin voltage, VN -- V 10 8 6 4 2 ICCO -- Ta VCC = 13.2V RL = Open Rg = 0 160 140 120 100 80 60 40 20 0 0 4 8 12 16 20 24 Supply voltage, VCC -- V PO -- Ta 36 Total harmonic distortion, THD -- % Output power, PO -- W 32 RL = 2 Ω 30 26 24 VCC = 13.2V Rg = 600Ω f = 1kHz THD = 10% Dual channel drive 22 RL = 4Ω 20 18 16 -40 -20 0 20 40 60 Ambient temperature, Ta -- °C 80 0 20 60 80 100 JK470823 THD -- Ta VCC = 13.2V RL = 4Ω Rg = 600Ω f = 1kHz PO = 2W Dual channel drive 3 2 0.1 7 5 3 2 -40 100 40 Ambient temperature, Ta -- °C -20 0 20 40 60 Ambient temperature, Ta -- °C JK470824 VN -- VST 8 -20 5 34 28 0 -40 28 JK470822 80 100 JK470825 Amp ON time -- C3 1.2 7 Amp ON time -- s Output pin voltage, VN -- V 1.0 6 5 4 3 VCC = 13.2V RL = 4Ω Rg = 0 Apply VST to standby pin (pin 5) through 10kΩ. 2 1 0 0 1 2 3 4 5 6 Standby pin applied voltage, VST -- V 7 0.8 0.6 0.4 0.2 8 JK470826 0 2 VCC = 13.2V VST = 5V (Apply to pin 5 through 10kΩ.) 3 5 7 10 2 C3 -- μF 3 5 7 100 2 JK470827 PS No. A1783-8/9 LA4708N ORDERING INFORMATION Device LA4708N-E Package SIP18H (Pb-Free) Shipping (Qty / Packing) 15 / Fan-Fold ON Semiconductor and the ON logo are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). 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