Last Updated on March 9, 2026 by omar Gamaleldin
LM1111CN Voltage Comparator IC DIP-16
The LM1111CN Voltage Comparator IC is a precision analog comparator designed to compare two input voltages and produce a digital output indicating which input is higher. Comparator ICs such as the LM111 series are widely used in electronic circuits for threshold detection, signal conditioning, and analog-to-digital interface applications.
This device compares a reference voltage applied to one input with an analog signal applied to the other input. When the input voltage exceeds the reference threshold, the output switches state, enabling reliable detection of voltage changes in monitoring and control systems.
Features:
- Precision voltage comparator for analog signal comparison.
- Low input bias current for improved measurement accuracy.
- Wide operating supply voltage range.
- Compatible with TTL, RTL, DTL, and MOS logic families.
Specifications:
| Parameter | Value |
|---|---|
| Part Number | LM1111CN |
| Manufacturer | National Semiconductor |
| Function | Dolby B Noise Reduction Processor |
| Package Type | DIP-16 |
| Mounting Type | Through Hole |
| Supply Voltage | 8VDC-16VDC (typical 12VDC) |
| Operating Temperature | 0°C-70°C |
Pin Configuration:
| Pin Number | Pin Name | Function/Description |
|---|---|---|
| 1 | VARIABLE IMPEDANCE INPUT | Variable impedance input |
| 2 | AMPLIFIER B INPUT | Amplifier B input |
| 3 | AMPLIFIER B OUTPUT | Amplifier B output |
| 4 | BIAS | Bias |
| 5 | AMPLIFIER A INPUT | Amplifier A input |
| 6 | AMPLIFIER A OUTPUT | Amplifier A output |
| 7 | AMPLIFIER EK OUTPUT | Amplifier EK output |
| 8 | DECOUPLING | Decoupling |
| 9 | GROUND | Ground |
| 10 | AMPLIFIER D FEEDBACK DECOUPLING | Amplifier D feedback decoupling |
| 11 | AMPLIFIER D OUTPUT | Amplifier D output |
| 12 | RECTIFIER INPUT | Rectifier input |
| 13 | RECTIFIER BIAS | Rectifier bias |
| 14 | RECTIFIER OUTPUT | Rectifier output |
| 15 | VARIABLE IMPEDANCE CONTROL | Variable impedance control |
| 16 | POSITIVE SUPPLY | Positive supply |
Applications:
- Vintage cassette tape deck repair and restoration.
- Analog audio recording and playback equipment servicing.
- Dolby B noise reduction circuits in consumer and professional hi-fi systems.
- Maintenance of 1970s–1980s cassette recorders and reel-to-reel tape machines.
Package Include:
1x LM1111CN Voltage Comparator IC DIP-16
Datasheet:
Note: This datasheet is NOT for the exact LM1111CN model but for the improved LM1112 version; however, the LM1112 is fully pin-compatible and serves as the official reference datasheet for the LM1111CN.