DS2165Q

Digital Signal Processor Dsp Overview

The DS2165Q is a dedicated digital-signal-processing (DSP) chip optimized for adaptive-differential pulse-code modulation (ADPCM) speech compression. It compresses/expands 64kbps PCM voice to/from 32kbps, 24kbps, or 16kbps rates. The device features dual fully independent channels supporting two expansions, two compressions, or one of each. It includes a high-performance 10 MIPS DSP engine and interfaces directly to serial TDM backplanes. Input-to-output delay is less than 375µs. It operates on a single +5V supply with low-power CMOS technology.

Digital Signal Processor Dsp Feature Summary

• Compresses/expands 64kbps PCM to 32kbps (G.721), 24kbps (T1.303), or 16kbps (proprietary).
• Dual independent channel architecture allows simultaneous expansion/compression configurations.
• On-board time-slot assigner-circuit (TSAC) supports Channel Associated Signaling (CAS).
• Hardware mode available for voice storage applications without host processor control.

Digital Signal Processor Dsp Applications

• Voice storage systems requiring hardware-mode operation.
• Telecommunications equipment utilizing TDM backplanes.
• Systems interfacing directly with combo-codec devices.

Digital Signal Processor Dsp Procurement Notes

Verify the specific voltage variant required; the standard DS2165Q operates at +5V, while the DS2165QL variant supports 3V operation. Confirm package availability in 28-pin PLCC. Check for any known errata associated with specific manufacturing revisions via official manufacturer documentation before finalizing procurement specifications.

Digital Signal Processor Dsp Selection Notes

Select the DS2165Q if a host processor is unavailable, as it supports a hardware mode where control bits are mapped to external pins. Choose the software mode if dynamic algorithm switching or complex time-slot assignment is required via a serial port. Ensure the system provides a stable 10MHz master clock for the DSP engine. Verify compatibility with A-law or µ-law data formats based on network requirements.

Digital Signal Processor Dsp Part Context

The DS2165Q belongs to the ADPCM processor family from Analog Devices/Maxim Integrated. It is designed to work in conjunction with codec/filter devices such as the TP305X, ETC505X, MC1455XX, TCM29CXX, and HD44238C. The component serves as a bridge between PCM voice data and compressed ADPCM streams in telecom infrastructure.

Digital Signal Processor Dsp Replacement Considerations

No public confirmed substitute part numbers are documented in the provided source material.

Digital Signal Processor Dsp FAQ

How does the DS2165Q handle Channel Associated Signaling (CAS)?

It automatically switches from the 32kbps algorithm to the 24kbps algorithm upon detecting a double-wide frame-sync pulse, allowing signaling data insertion into the LSB bit position.

What is the maximum input-to-output delay?

The total delay from PCM sample capture to output is always less than 375µs across all three compression algorithms.

Can the compression algorithm be changed during operation?

Yes, in software mode, the user can switch between the three available algorithms on-the-fly by updating the control register before the next input sample arrives.