lm1875 amplifier circuit diagram stereo 2x 30W

| | , ,

lm1875 amplifier circuit diagram stereo 2x 30W. This is an audio amplifier circuit using integrated LM1875 stereo to 2 × 30 Watts. With power supply for ease of assembly for any hobbyist. With a power of up to 20 Watts stereo amplifier that is suitable for use as power audio amplifier in various applications such as power amplifier for PC audio, FM radio, MP3 speaker, finally you’re sure to find great uses for this amplifier with LM1875 easy to assemble.

This is a circuit that has a while that was here in the drafts of the blog, so this early morning “without sleep” I decided to complete the article. This is a stereo audio amplifier circuit using integrated LM1875 for 2 × 30 Watts, as usual now in the new circuits this also comes with the source circuit to facilitate assembly for any hobbyist. With a power of up to 30 Watts per channel, this amplifier is suitable for use as a power stage in various applications as an amplifier for PC speakers, active speakers, surround sound, FM radio, MP3 player. It can also be used to tune those USB boxes, and the user will certainly find great uses for this amplifier with LM1875T stereo of easy assembly.

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 4 or 8 load on ±25V supplies. Using an 8 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.

Get new posts by email:
Follow us on social media

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.

  • Up to 30 watts output power
  • AVO typically 90 dB
  • Low distortion: 0.015%, 1 kHz, 20 W
  • Wide power bandwidth: 70 kHz
  • Protection for AC and DC short circuits to ground
  • Thermal protection with parole circuit
  • High current capability: 4A
  • Wide supply range 16V-60V
  • Internal output protection diodes
  • 94 dB ripple rejection
  • Plastic power package TO-220
Lm1875 Pinout Datasheet Lm1875T
Lm1875 Pinout Datasheet Lm1875T

About the amplifier circuit:

The project relies on a symmetrical type power supply and a double transformer from 9 to 18 VAC can be used, the filter capacitors (C5 and C6) can be from 2,200uF to 6,800uF. The rectifier bridge can be KBL406 or equivalent.

At the audio input C9 and R5 form a high pass RC filter, where R5 also determines the input impedance, the cutoff frequency will be 3.2 Hz. Resistor R7 and capacitor C11 form a low-pass filter, to avoid RF signals in the amplifier, and the cutoff is at 482.5 KHz, just below the AM band.

Schematic lm1875 amplifier circuit diagram stereo 2x 30W

Schematic Lm1875 Amplifier Circuit Diagram Stereo 2X 30W
Schematic Lm1875 Amplifier Circuit Diagram Stereo 2X 30W

Suggested printed circuit board PCB lm1875T amplifier circuit stereo 2x 30W

Suggested Printed Circuit Board Pcb Lm1875 Amplifier Circuit Stereo 2X 30W
Suggested Printed Circuit Board Pcb Lm1875T Amplifier Circuit Stereo 2X 30W
Suggested Printed Circuit Board Pcb Component View Lm1875 Amplifier Circuit Stereo 2X 30W
Suggested Printed Circuit Board Pcb Component View Lm1875 Amplifier Circuit Stereo 2X 30W
Suggested Printed Circuit Board Pcb Component Silk Lm1875 Amplifier Circuit Stereo 2X 30W
Suggested Printed Circuit Board Pcb Component Silk Lm1875 Amplifier Circuit Stereo 2X 30W

BOM to assemble the power amplifier with LM1875 IC.

Last Update: 09/14/2021 12:55 PM

Part Valor Description Quantity
Capacitors
C1, C2, C3, C4 100nF Ceramic Capacitor 4
C5, C6 4700µF/35V Electrolytic capacitor 2
C9, C10 2.2µF Polyester capacitor 2
C11, C12 330pF Ceramic Capacitor 2
C13, C14 47µF/35V Electrolytic capacitor 2
C15, C16 220nF Polyester capacitor 2
Semiconductors
B1 KBL406 or equivalent Bridge rectifier 1
IC1, IC2 LM1875 or LM1875T Audio amplifier integrated circuit. 2
LED1, LED2 Red Led 5 mm LED 5 mm 4
Resistors 1/4W
R1, R2 10k Brown, Black, Orange, Gold 2
R3, R4 1M Brown, Black, Green, Gold 2
R5, R6, R11, R12 22k Red, Red, Orange, Gold 4
R7, R8, R9, R10 1K Brown, Black, Red, Gold 4
R13, R14 1 Ohm / 2W Brown, Black, Gold, Gold 2
Miscellaneous
CN1 AC Terminal block 2 pin 5.08 mm 1
CN2 IN1 2.54 mm 2-way JST Male Connector 2.54 mm 1
CN3 IN2 2.54 mm 2-way JST Male Connector 2.54 mm 1
CN4, CN5 OUT-L Terminal block 2 pin 5.08 mm 2
Solder, Wires, Box, Solder, Heat sink for the IC, PCB, etc.

Download PDF, PNG, Postscript Gerber files for assembling the power amplifier with LM1875 IC
Download PDF

Download Mirror

Download the PDF datasheet of the LM1875 IC

Download PDF datasheet of the KBL406 rectifier bridge

How useful was this post?

Click on a star to rate it!

Average rating / 5. Vote count:

No votes so far! Be the first to rate this post.

As you found this post useful...

Share on the social networks!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?

Previous

TV remote control Jammer Circuit 555 IR Remote block

FM Transmitter Circuit Boardless Assembly

Next

11 thoughts on “lm1875 amplifier circuit diagram stereo 2x 30W”

  1. This schematic is incorrect. R5 and R11 should go from pin 4 to pin 2 of their respective ICs, not the junction of the 10k resistor and the 2.2uf capacitor. Also, much better performance can be achieved using a centre-tapped transformer and dual-ended supply. See the datasheet’s typical application schematic.

    Reply
  2. 12v dc amplifier stereo audio top hi fi power sistem please sir my numbers 09417825411, 09417812056 please back call me

    Reply
  3. Why my left out make noisy sound, but the right one dont issue anything. That problem can be related with suuply?
    Help !!!!!!!!!!

    Reply

Leave a Comment