ZHCSIC9D April 2016 – June 2018 LMH1219
PRODUCTION DATA.
After the input signal passes through the CTLE, the equalized data is fed into the clock and data recovery (CDR) block. Using an internal PLL, the CDR locks to the incoming equalized data and recovers a clean internal clock to re-sample the equalized data. The LMH1219 CDR is able to tolerate high input jitter, tracking low frequency input jitter below the PLL bandwidth while reducing high frequency input jitter above the PLL bandwidth.
The supported data rates are listed in Table 3. By default, IN0 locks to SMPTE data rates and IN1 locks to the 10 GbE data rate, according to the IN_OUT_SEL pin logic shown previously in Table 2. IN1 can be programmed to lock to SMPTE data rates via register control by applying the appropriate override bit values. For more information, refer to the LMH1219 Register Map and Programming Guide.
| INPUT | DATA RATE | RECLOCKER MODE |
|---|---|---|
| IN0+ | 11.88 Gbps, 5.94 Gbps, 2.97 Gbps, 1.485 Gbps, 270 Mbps(1) | Reclocker Enabled |
| 125 Mbps | Reclocker Disabled (CDR Bypassed) | |
| IN1± | 10.3125 Gbps | Reclocker Enabled |
| 1.25 Gbps | Reclocker Disabled (CDR Bypassed) |
NOTE
If the selected data rate (SMPTE or 10 GbE) is changed while the device is operating with active data, a CDR reset and release is required for the CDR to re-acquire lock. If the input data signal is toggled off and on after the selected data rate is changed, the Carrier Detect circuit will reset the CDR. In this case, no register write is needed for the CDR to re-acquire lock.