مدار مجتمع (آی سی) آی‌سی صوتی ویژه

Product Attributes

Introduction

CD22354A and CD22357A are monolithic silicon-gate, dual-polysilicon CMOS ICs containing bandlimiting filters and companding A/D and D/A conversion circuits conforming to AT&T D3/D4 specifications and CCITT recommendations. The CD22354A provides AT&T μ-law characteristics, while the CD22357A provides CCITT A-law companding characteristics. The primary application of the CD22354A and CD22357A is in telephone systems. These circuits perform analog-to-digital conversion between subscriber loops and PCM trunks in digital switching systems. With flexible features including synchronous and asynchronous operation and variable data rates, the CD22354A and CD22357A are well suited for use in PABXs, central office switching systems, digital telephones, and other applications requiring precise A/D and D/A conversion with minimal conversion time.

Features

• Meets or exceeds all AT&T D3/D4 specifications and CCITT recommendations
• Complete codec and filter system: sample-and-hold and auto-zero functions require no external components. Receive output filter features (SIN X)/X correction and additional 8kHz suppression
• Variable data clock — 64kHz to 2.1MHz
• Receiver includes power-on click filter
• TTL or CMOS compatible logic
• ESD protection on all inputs and outputs

Applications

• Private Automatic Branch Exchange (PABX)
• Central Office Switching Systems
• Digital Telephones
• Cellular Telephone Switching Systems
• Voice Scrambler - Descrambler