ZHCSKL4 December 2019 ADC3421-Q1
PRODUCTION DATA.
The device clock inputs can be driven differentially (sine, LVPECL, or LVDS) or single-ended (LVCMOS), with little or no difference in performance between them. The common-mode voltage of the clock inputs is set to 0.95 V using internal 5-kΩ resistors. The self-bias clock inputs of the ADC3421-Q1 can be driven by the transformer-coupled, sine-wave clock source or by the ac-coupled, LVPECL and LVDS clock sources, as shown in Figure 36, Figure 37, and Figure 38. See Figure 39 for details regarding the internal clock buffer.
Figure 37. LVDS Clock Driving Circuit
Figure 38. LVPECL Clock Driving Circuit
A single-ended CMOS clock can be ac-coupled to the CLKP input, with CLKM connected to ground with a 0.1-μF capacitor, as shown in Figure 40. However, for best performance the clock inputs must be driven differentially, thereby reducing susceptibility to common-mode noise. For high input frequency sampling, TI recommends using a clock source with very low jitter. Band-pass filtering of the clock source can help reduce the effects of jitter. There is no change in performance with a non-50% duty cycle clock input.
Figure 40. Single-Ended Clock Driving Circuit