Rate-agile, I/O-agnostic CDRs offer adaptive equalization
By Joshua Israelsohn -- EDN, July 24, 2003
Mindspeed Technologies’ new family of four CDR (clock- and data-recovery) ICs cover the spectrum from 42 Mbps to 3.2 Gbps for Ethernet, Fibre Channel, InfiniBand, SONET, and backplane applications (Picture). The M21001, M21011, and M21012 comprise four independent CDR ICs that operate at 42 to 800 Mbps, 1 to 3.2 Gbps, and 42 Mbps to 3.2 Gbps, respectively. The octal M21050 shares the M21011’s range. The CDR ICs offer CML, InfiniBand, LVDS, and LVPECL I/O compatibility as user-selectable options.
Adaptive input equalization improves the receiver-channel performance and mitigates the effects of inexpensive board materials. Output pre-emphasis allows you to drive pc-board traces as long as 60 in. The multichannel, multirate CDRs feature an on-chip frequency synthesizer so that you can operate heterogeneous channels from a single reference clock. Alternatively, the CDRs can acquire channel frequency without an external time reference. Jitter tolerance is 0.65 UI (unit interval); jitter generation 2.5 million UI.
You can configure the devices either by pin-strapping or through an I2C interface. The quad devices operate from 1.8. 2.5, or 3.3V supplies; the octal CDR IC requires 1.8 or 2.5V. The M21011 and 12 dissipate 340 mW with all channels running; the octal M21050 dissipates 1W.
Price for the CDR ICs are $31.95 for the M21001, $64.95 for the M21011, and $84.95 for the M21012 or M21050 (OEM quantities).
Mindspeed Technologies, www.mindspeed.com.
