ADPCM Codec

This technical summary provides a brief description of the MC14LC5540 ADPCM Codec. A complete data book for the MC14LC5540 is available and can be ordered from your local Motorola sales office. The data book number is MC145540/D.

The MC14LC5540 ADPCM Codec is a single chip implementation of a PCM Codec–Filter and an ADPCM encoder/decoder, and therefore provides an efficient solution for applications requiring the digitization and compression of voiceband signals. This device is designed to operate over a wide voltage range, 2.7 to 5.25V and, as such, is ideal for battery powered as well as ac powered applications. The MC14LC5540 ADPCM Codec also includes a serial control port and internal control and status registers that permit a microcomputer to exercise many built–in features.

The ADPCM Codec is designed to meet the 32 kbps ADPCM conformance requirements of CCITT Recommendation G.721–1988 and ANSI T1.301. It also meets ANSI T1.303 and CCITT Recommendation G.723–1988 for 24 kbps ADPCM operation, and the 16 kbps ADPCM standard, CCITT Recommendation G.726. This device also meets the PCM conformance specification of the CCITT G.714 Recommendation.

• Single 2.7 to 5.25 V Power Supply

• Typical 2.7 V Power Dissipation of 43 mW, Power–Down of 15 µW

• Differential Analog Circuit Design for Lowest Noise

• Complete Mu–Law and A–Law Companding PCM Codec–Filter

• ADPCM Transcoder for 64, 32, 24, and 16 kbps Data Rates

• Universal Programmable Dual Tone Generator

• Programmable Transmit Gain, Receive Gain, and Sidetone Gain

• Low Noise, High Gain, Three Terminal Input Operational Amplifier for Microphone Interface

• Push–Pull, 300 Ω Power Drivers with External Gain Adjust for Receiver Interface

• Push–Pull, 300 Ω Auxiliary Output Drivers for Ringer Interface

• Voltage Regulated Charge Pump to Power the Analog Circuitry in Low Voltage Applications

• Receive Noise Burst Detect Algorithm

• Order Complete Document as MC145540/D

• Device Supported by MC145537EVK ADPCM Codec Evaluation Kit