TEA1330 Low-Voltage Telephone Transmission Circuit DIP-18 (TEA1330 IC)
The TEA1330 is a high-performance integrated circuit designed for low-voltage telephone sets. Housed in an 18-pin DIP package, it performs all speech and line interface functions, including electronic switching between dialing and speech modes. It is optimized for use with low-impedance dynamic or magnetic microphones, making it a staple for high-quality analog landline phones.
In India, the TEA1330 is frequently used for telecom equipment repair and in the production of specialized intercom systems. It is engineered to maintain stable operation even on long subscriber lines where the available voltage is significantly reduced.
Key Features
- Low-Voltage Performance: Designed to operate effectively at low line voltages, ensuring reliability in varying network conditions.
- Integrated Dialer Interface: Provides a stable regulated voltage (VCC) to power external pulse or DTMF dialer ICs.
- Symmetrical Transmitting Inputs: Specifically tuned for dynamic microphones, offering excellent noise rejection.
- Automatic Gain Control (AGC): Built-in line-loss compensation automatically adjusts microphone and earpiece gain based on the line current.
- Flexible Earpiece Support: Capable of driving magnetic, dynamic, or piezo-electric earpieces with high efficiency.
- Mute Functionality: Includes a dedicated Mute input to disable speech during dialing sequences.
Specifications
- IC Type: Telephone Transmission Circuit
- Operating Line Current: 10 mA to 140 mA
- Microphone Gain: ~52 dB (Adjustable)
- Earpiece Gain: ~26 dB (Adjustable)
- Minimum Line Voltage: ~3.8V (at 20mA)
- Internal Supply Voltage: 2.4V to 3.8V
- Package Type: PDIP-18
- Operating Temperature: -25°C to +75°C
Pinout Configuration (18-Pin DIP)
- Pin 1 (LN): Positive Line Terminal
- Pin 2 (GAS1): Transmitting Gain Adjustment 1
- Pin 3 (GAS2): Transmitting Gain Adjustment 2
- Pin 4 (QR+): Non-Inverting Receiver Output
- Pin 5 (GAR): Receiving Gain Adjustment
- Pin 6 (MIC-): Inverting Microphone Input
- Pin 7 (MIC+): Non-Inverting Microphone Input
- Pin 8 (STAB): Current Stabilizer
- Pin 9 (VEE): Negative Supply (Ground)
- Pin 10 (QR-): Inverting Receiver Output
- Pin 11 (IR): Receiving Amplifier Input
- Pin 12 (PD): Power-Down Input
- Pin 13 (DTMF): DTMF Signal Input
- Pin 14 (MUTE): Mute Control Input
- Pin 15 (VCC): Regulated Supply Output (for Dialer)
- Pin 16 (REG): Voltage Regulator Decoupling
- Pin 17 (AGC): Automatic Gain Control
- Pin 18 (SLPE): DC Resistance (Slope) Adjustment
