LM1875 is a monolithic power amplifier IC (Fully integrated circuit inside as an amplifier) used in major home audio systems. The main specs of this IC is high quality audio, power output, low distortion and few components is needed to build an amp. So in this article sharing LM1875 datasheet including Pinout, Characteristics and Equivalent IC’s.
Overview of LM1875 IC
- The speaker Output Power is up to 20W in continuous 4Ω or 8Ω loads with 25V dual supply
- Amplifier has Low Distortion and is around 0.015% THD at 1 kHz, 20W output
- Wide Power Bandwidth range of 70 kHz
- The IC can able to handle high Current of 4A peak output current
- The IC has Protection Features such as Short-circuit, thermal shutdown, and internal current limiting
- Operating Voltage Range: ±16V to ±30V (single supply up to 60V)
LM1875 IC Pinout Diagram
LM1875 IC Pinout Configurations
| Pin No | Name | Description |
|---|---|---|
| 1 | Non-Inverting Input (+IN) | Positive input terminal for the audio signal |
| 2 | Inverting Input (-IN) | Negative input terminal, usually used for feedback connection |
| 3 | V- (Negative Supply) | Negative power supply rail |
| 4 | Output | Audio output pin |
| 5 | V+ (Positive Supply) | Positive power supply rail |
Characteristics of LM1875
| Parameter | Value | Notes |
|---|---|---|
| Supply Voltage Range | ±16V to ±30V in dual and Max 60V in single supply. | Wide operating range |
| Output Power | 20W @ 4Ω/8Ω, ±25V | 30W possible with ±30V |
| THD (1 kHz, 20W) | 0.015% | Very low distortion |
| Open Loop Gain | 90 dB | High gain |
| Slew Rate | 8 V/μs | Fast response |
| Input Offset Voltage | ±1 mV (typ) | Stable DC characteristics |
| Ripple Rejection | 94 dB | Excellent power supply rejection |
| Current Limit | 4A | Built-in protection |
| Thermal Shutdown | 150-170°C | Auto recovery |
Equivalent IC for Replacement
The pin configuration and the size of the IC is considerable based on the exact replacement, so you can use the given IC as equivalent replacement for LM1875.
- TDA2050
- TDA2030
- LM675
Applications
- The LM1875 IC is used to Build Hi-Fi stereo amplifiers.
- Also used for Audio preamplifiers and power amplifiers
- With 2 IC it can build a Bridge amplifier designs for high power.
- Used in Musical instrument amplifiers
