MC34119D

Audio Amplifiers Overview

The MC34119D is a low power audio amplifier integrated circuit designed for telephone applications, such as speakerphones. It features differential speaker outputs to maximize output swing at low supply voltages starting from 2.0 V, eliminating the need for coupling capacitors. The device operates within a wide supply voltage range of 2.0 V to 16 V and draws a typical quiescent current of 2.7 mA. In power-down mode, the current drops to 65 μA. It drives loads of 8.0 Ω or higher, delivering over 250 mW into a 32 Ω speaker with total harmonic distortion typically at 0.5%. Gain is adjustable via external resistors.

Audio Amplifiers Feature Summary

• Provides differential speaker outputs to maximize voltage swing at low supply voltages without requiring coupling capacitors.
• Includes a Chip Disable pin that allows powering down the IC or muting the input signal to conserve energy.
• Supports adjustable closed-loop gain set by two external resistors, suitable for voice band applications.
• Requires minimal external components for configuration, simplifying circuit design.

Audio Amplifiers Applications

• Telephone systems
• Speakerphones

Audio Amplifiers Procurement Notes

Verify the specific package suffix matches the required form factor, as the D suffix denotes an SO-8 plastic package. Confirm the operating temperature range aligns with system requirements, noting the standard range is –20°C to +70°C. Ensure the ordering part number includes any necessary environmental compliance suffixes if specified in the final bill of materials. Cross-reference the manufacturer's latest datasheet revision to confirm pinout and electrical characteristics remain unchanged.

Audio Amplifiers Selection Notes

Select this component when designing battery-powered or line-powered audio circuits requiring low static current consumption. It is suitable for applications needing differential drive to speakers without output coupling capacitors. Consider the thermal resistance of the SO-8 package when calculating maximum power dissipation limits at elevated ambient temperatures. Verify that the required gain setting falls within the adjustable range provided by external feedback resistors.

Audio Amplifiers Part Context

The MC34119 is a low power audio amplifier originally manufactured by Motorola and now associated with NXP USA Inc. It is available in multiple packages including Plastic DIP (P suffix), SOIC (D suffix), and TSSOP (DTB suffix). The device is intended primarily for telephone applications like speakerphones, offering high open-loop gain and low distortion.

Audio Amplifiers Replacement Considerations

Check for direct replacements with identical pinouts and electrical specifications if the MC34119D is discontinued. Verify compatibility with existing PCB layouts and external component values. Ensure substitute parts support the same supply voltage range and power-down functionality.

Audio Amplifiers FAQ

How does the Chip Disable pin function?

The Chip Disable pin (Pin 1) controls the operational state. A logic low (0 V to 0.8 V) enables normal operation, while a logic high (2.0 V to VCC) powers down the IC or mutes the input signal.

What is the purpose of the FC1 and FC2 pins?

FC1 and FC2 are used to control power supply rejection and noise filtering. Capacitors connected to these pins improve PSRR and affect the turn-on time of the circuit.