AmplifierCircuits

Circuit Description      The stereo signals coming from the line outputs of the car radio amplifier are mixed at the input and, after the Level Control, the signal enters the buffer IC1A and can be phase reversed by means of SW1. This control can be useful to allow the subwoofer to be in phase with the loudspeakers of the existing car radio. Then, a 12dB/octave variable frequency Low Pass filter built around IC1B, Q1 and related components follows, allowing to adjust precisely the low pass frequency from 70 to 150Hz. Q2, R17 and C9 form a simple dc voltage stabilizer for the input and filter circuitry, useful to avoid positive rail interaction from the power amplifier to low level sections.      This unit is intended to be connected to an existing car stereo amplifier, adding the often required extra "punch" to the music by driving a subwoofer. As very low frequencies are omnidirectional, a single amplifier is necessary to drive this dedicated louds...

Circuit description: Here is the circuit diagram of a simple subwoofer filter that can be operated from a 12V DC supply. Such a circuit is very useful in automobile subwoofer applications. The circuit is nothing but a low pass filter whose pass frequency can be adjusted between 60 to 160 Hz. The circuit is designed around the TL072 dual BIFET opamp IC. Out of the two opamps inside the chip, IC1A is wired as a buffer. The left and right audio inputs after mixing is fed to the input of the IC1A using the DPDT switch S1. Switch S1 is the phase control switch which can be used to make the subwoofer in phase with other speakers. When S1 is in position 2, 180 degree phase shift will be induced.POT R7 can be used for controlling the level. IC1B forms the low pass filter whose pass frequency can be controlled by adjusting the dual gang POT R13. Circuit Features: The circuit can be powered from 12V DC. IC1 must be mounted on a holder. S1 is a DPDT switch. R13 should be a dual gang l...

LM1875   g eneral description: LM1875 pcb layout The LM1875 is a monolithic power amplifier offering very low distortion and high quality performance for consumer audio applications. The LM1875 delivers 20 watts into a 4Ω or 8Ω load on ±25V supplies. Using an 8Ω load and ±30V supplies, over 30 watts of power may be delivered. The amplifier is designed to operate with a minimum of external components. Device overload protection consists of both internal current limit and thermal shutdown.The LM1875 design takes advantage of advanced circuit techniques and processing to achieve extremely low distortion levels even at high output power levels. Other outstanding features include high gain, fast slew rate and a wide power bandwidth, large output voltage swing, high current capability, and a very wide supply range. The amplifier is internally compensated and stable for gains of 10 or greater. LM1875  amplifier circuit : LM1875 AUDIO AMPLIFIER 20W...

LX1720  g eneral description: The LX1720 controller IC contains the necessary functions to implement a stereo Class-D audio amplifier. A Class-D amplifier is a "switching" amplifier that converts a low-level, analog, audio input signal into a highpower, pulse-width modulated (PWM) output. The switching frequency is much higher than the audio band which allows high frequency out-of-band components to be removed with a simple LC filter. The LX1720 generates a PWM output by controlling external MOSFET's connected in a full-bridge configuration. Because the MOSFET's are either full "on" or full "off", their power dissipation is minimal allowing maximum power to be delivered to the speaker. LX1720 Circuit: LX1720 Audio Amplifier 2x20W

TDA8922   g eneral description: The TDA8922 is a high efficiency class-D audio power amplifier with very low dissipation.  The typical output power is 2 × 25 W. The device is available in the HSOP24 power package with a small internal heatsink and in the DBS23P through-hole power package. Depending on the supply voltage and load conditions, a very small or even no external heatsink is required. The amplifier operates over a wide supply voltage range from ±12.5 to ±30 V and consumes a very low quiescent current. TDA8922  features : High efficiency (∼90%) Operating supply voltage from ±12.5 to ±30 V Very low quiescent current Low distortion Usable as a stereo Single-Ended (SE) amplifier or as amono amplifier in Bridge-Tied Load (BTL) Fixed gain of 30 dB in Single-Ended (SE) and 36 dB in Bridge-Tied Load (BTL) High output power Good ripple rejection Internal switching frequency can be overruled by an external clock No switch-on or swi...

TDA7490   g eneral description: The TDA7490 is a dual audio class D amplifier assembled in Flexiwatt 25 package; it is specially designed for high efficiency application mainly for TV and Home Stereo sets. TDA7490 features:  25W + 25W OUTPUT POWER: RL = 8Ω/4Ω; THD = 10% HIGH EFFICIENCY WIDE SUPPLY VOLTAGE RANGE (FROM ±10 TO ±25V) SPLIT SUPPLY TURN OFF/ON POP FREE ST-BY AND MUTE FEATURES SHORT CIRCUIT PROTECTION ACROSS THE LOAD THERMAL OVERLOAD PROTECTION EXTERNALLY SINCHRONIZABLE BRIDGE CONFIGURATION TDA7490 amplifier diagram, circuits: TDA7490 Audio Amplifier 2x25W TDA7490 layout, pcb: TDA7490 layout, pcb TDA7490 layout, pcb

45 Watt Class B Amplifier Description 4 5W into 8 Ohm - 69W into 4 Ohm Easy to build - No setup required 45 Watt Class B Amplifier 45 Watt Class B Amplifier Description The main design targets for this amplifier were as follows: Output power in the 40 - 70W range Simple circuitry Easy to locate, low cost components Rugged performance No setup These goals were achieved by using a discrete-components op-amp driving a BJT complementary common-emitter output stage into Class B operation. In this way, for small output currents, the output transistors are turned off, and the op-amp provides all of the output current. At higher output currents, the power transistors conduct, and the contribution of the op-amp is limited to approximately 0.7/R11. The quiescent current of the op-amp biases the external transistors, and hence greatly reduces the range of crossover. The idea sprang up from a letter published on Wireless World, December 1982, page 65 written by N. M. Allinson, th...

STK4221   g eneral description: The STK4221II IC from SANYO is a dual high power amplifier chip, preferably suited for compact high power audio applications, for example in cars and luxury transport vehicle audio systems. The chip provides a hassle free stereo output through a single package and a hand full of few external components, making the construction of this circuit rather easy and straightforward. However since the idea presented here does not include a CD or a memory card driver circuit, the input may be derived from readymade audio sources like an ipod, CD walkman, cellphone etc. The circuit discussed here is intended specifically for car audio applications and provides a simple alternative for  making a 100 watt car stereo amplifier circuit. The diagram may be understood with the following points: An RC network formed by R5, R6 and C3, C4 together helps to reduce and filter stray frequency interferences and is therefore included at the input of th...

TDA1015   g eneral description: The TDA1015 is a monolithic integrated audio amplifier circuit in a 9-lead single in-line (SIL) plastic package. The device is especially designed for portable radio and recorder applications and delivers up to 4 W in a 4Ω load impedance. The very low applicable supply voltage of 3,6 V permits 6 V spplications. TDA1015  features : single in-line (SIL) construction for easy mounting separated preamplifier and power amplifier high output power thermal protection high input impedance low current drain limited noise behaviour at radio frequencies TDA1015  reference data : Supply voltage range VP 3,6 to 18 V Peak output current IOM max. 2,5 A Output power at dtot= 10% VP = 12 V; RL = 4 Ω Po typ. 4,2 W VP = 9 V; RL = 4 Ω Po typ. 2,3 W VP = 6 V; RL = 4 Ω Po typ. 1,0 W Total harmonic distortion at Po = 1 W; RL = 4 Ω dtot typ. 0,3 % Input impedance preamplifier (pin 8) |Zi | > 100 kΩ...

TDA7490   g eneral description: The TDA7490 is a dual audio class D amplifier assembled in Flexiwatt 25 package; it is specially designed for high efficiency application mainly for TV and Home Stereo sets.   TDA7490 Audio Amplifier 2 x 25W / 1 x 50W TDA7490  features : 25W + 25W OUTPUT POWER: RL = 8Ω/4Ω; THD = 10% HIGH EFFICIENCY WIDE SUPPLY VOLTAGE RANGE (FROM ±10 TO ±25V) SPLIT SUPPLY TURN OFF/ON POP FREE ST-BY AND MUTE FEATURES SHORT CIRCUIT PROTECTION ACROSS THE LOAD THERMAL OVERLOAD PROTECTION EXTERNALLY SINCHRONIZABLE BRIDGE CONFIGURATION TDA7490  sterio circuit diagram : TDA7490 Audio Amplifier 2 x 25W / 1 x 50W circuit diagram TDA7490  mono circuit diagram : TDA7490 Audio Amplifier 2 x 25W / 1 x 50W mono circuit diagram TDA7490  sterio circuit pcb : TDA 7490 pcb layout 

 TDA1562Q   g eneral description: Philips designers have further improved a number of properties of the IC, among which the power output. According to the Philips datasheet, the improved device, the TDA1562Q, can deliver 70 watts into 4 ohms, but that is at the cost of the distortion, which at 10 per cent is rather too high, even for in a car. The prototype of the design described in this article provides 54 watts into 4 ohms at 1 per cent distortion. Since the number of requisite external components is smaller than in the case of the earlier device, the printed-circuit board is even more compact than that for the February 1995 amplifier.  TDA1562Q  features : Low power dissipation during reproduction of music signals Proof against short-circuits Protection against excessive temperatures Standby switch No power-on or power-off clicks Visible error indication Measurement results (at Ub =14.4 V) Supply voltage 8–18 V Sensitivity 760 mV r.m...

TDA7560   g eneral description: TDA7560 is a 4 x 45W QUAD BRIDGE car audio amplifier plus HSD. The TDA7560’s inputs are ground-compatible and can stand very high input signals (± 8Vpk) without any performances degradation. If the standard value for the input capacitors (0.1mF) is adopted, the low frequency cut-off will amount to 16 Hz. The TDA7560 is a breakthrough BCD (Bipolar / CMOS / DMOS) technology class AB Audio Power Amplifierin Flexiwatt 25 package designed for high power car radio. The fully complementary P-Channel/N-Channel output structure allows a rail to rail output voltage swing which, combined with high output current and minimised saturation losses sets new power references in the car-radio field, with unparalleled distortion performances. TDA7560  features : 4 x 50W/4W MAX. 4 x 45W/4W EIAJ 4 x 30W/4W @ 14.4V, 1KHz, 10% 4 x 80W/2W MAX. 4 x 77W/2W EIAJ 4 x 55W/2W @ 14.4V, 1KHz, 10% EXCELLENT 2W DRIVING CAPABILITY HI-FI CLASS DISTORTION ...

TDA8922   g eneral description: The TDA8922 is a high efficiency class-D audio power amplifier with very low dissipation. The typical output power is 2 × 25 W. The device is available in the HSOP24 power package with a small internal heatsink and in the DBS23P through-hole power package. Depending on the supply voltage and load conditions, a very small or even no external heatsink is required. The amplifier operates over a wide supply voltage range from ±12.5 to ±30 V and consumes a very low quiescent current.  TDA8922 Audio Amplifier 2 x 25W TDA8922  features : High efficiency (∼90%) Operating supply voltage from ±12.5 to ±30 V Very low quiescent current Low distortion Usable as a stereo Single-Ended (SE) amplifier or as a mono amplifier in Bridge-Tied Load (BTL)  Fixed gain of 30 dB in Single-Ended (SE) and 36 dB in Bridge-Tied Load (BTL) High output power Good ripple rejection Internal switching frequency can be overruled by an...