VE8921
Dual Channel FXS + Single Channel FXO Chip Set
Product is discontinued and not allowed for new designs.
Use miSLIC Series instead.
Overview
The VE8921 chip set is a highly integrated, low-cost, 2FXS + 1FXO chip set that is optimized for residential VoIP gateways such as voice enabled DSL modems, set-top boxes, and analog terminal adapters. The chip set implements simultaneous FXS and FXO functionality by providing the necessary voice interface functions to connect to and power a telephone and an isolated DAA for connection to the PSTN. On the digital side, the VE8921 chip set provides standard MPI and PCM interfaces to a VoIP processor. The VE8921 chip set, coupled with the VoicePath API-II (VP API-II) enables designers to offer a single hardware design that is software programmable for worldwide markets. The VP API-II 'C' code is used to abstract the devices from application code while providing functions for controlling, supervising, and testing a set of subscriber lines. The chip set utilizes patented low value PCB capacitors, resulting in best in class DAA performance in both common mode and RF immunity. |
Detailed Block Diagram

Features & Benefits
- Highly integrated, low-cost 1FXS + 1FXO chip set for VoIP access devices
- Software programmable for worldwide FXS and FXO operation
- Lowest RBOM cost in the industry
- FXS channel performs all the standard BORSCHT functions
- Additional FXS features:
- Built-in DC/DC controller for high-voltage battery generation
- Integrated balanced ringing generator with up to 92 VPK
- 120 mW typical on-hook idle power consumption, less than half that of competing solutions
- Wideband audio support
- GR-909/TIA-1063 test support
- FXO channel performs all PSTN interface functions with software programmable parameters:
- DC mask and AC impedance
- TX and RX signal equalization
- DTMF and pulse dialing
- Ring detection
- FXO line and event monitoring:
- on-hook voltage, off-hook current
- Ringing, polarity reversal, Caller ID, disconnect, line in use, and parallel phone off-hook
- Single DAA hardware design for worldwide compliance, including:
- TIA-968-A, ETSI ES 203-021, JATE, AUSTEL, and YD/T 514
- Adaptive DAA hybrid balance adjustment with DSL filter support
- DAA isolation using no-cost PCB capacitors for low RBOM and exceptional common mode rejection performance
- Direct FXO to FXS voice path with no processor buffering required
- VoicePath API-II Software
- Significantly reduces development and testing time
- Enables modular product design with multiple combinations of FXS and FXO channels
- Supported by SDK, development board and reference designs