R31DS0128EU0116 Rev.1.16

Page 28

Nov 17, 2025

RC32312, RC32308 Datasheet

Figure 10. HCSL Internal Termination

Figure 11 shows an HCSL driver direct-coupled with an HCSL receiver and configured for external termination. If

the HCSL receiver has an internal 100Ω termination resistor then it will reduce the signal amplitude at the receiver

by 50% – this can be mitigated by adjusting the output amplitude of the driver.

Figure 11. HCSL External Termination

For alternative termination schemes, see HCSL Terminations in Quick Guide - Output Terminations located on the

RC32312/RC32308 product page, or contact Renesas for support.

4.5.2

Direct-Coupled LVDS Termination

For LVDS receivers, RC32312, RC32308 clock outputs should be configured for LVDS, and should be direct-

coupled. The RC32312, RC32308 supports several programmable LVDS voltage swing and common mode

options.

Figure 12 shows an LVDS driver direct-coupled with an LVDS receiver. The recommended value for the

termination resistor (R1) is between 90Ω and 132Ω. The actual value should be selected to match the differential

impedance (Z0) of the transmission line. To avoid transmission-line reflection issues, R1 should be surface-

mounted and placed as close to the receiver as practical.

For alternative termination schemes, see LVDS Terminations in Quick Guide - Output Terminations located on the

RC32312/RC32308 product page, or contact Renesas for support.

Figure 12. LVDS Termination

ZO = 50Ω

ZO = 50Ω

HCSL Receiver

R1

100Ω

R1 is optional for improved

impedance matching.

HCSL Driver

RO1

RO2

ZO = 50Ω

HCSL Driver

R1

50Ω

R2

50Ω

ZO = 50Ω

HCSL Receiver

ZO = 50Ω

LVDS Driver

R1

100Ω

ZO = 50Ω

LVDS Receiver