MPC8610EC datasheet(57/96 Pages) NXP

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Electrical Characteristics

MPC8610 Integrated Host Processor Hardware Specifications, Rev. 2

Freescale Semiconductor

— For external AC-coupled connection, there is no common mode voltage requirement for the clock driver. Since

the external AC-coupling capacitor blocks the DC level, the clock driver and the SerDes reference clock receiver

operate in different command mode voltages. The SerDes reference clock receiver in this connection scheme has

its common mode voltage set to SGND. Each signal wire of the differential inputs is allowed to swing below and

above the command mode voltage (SGND). Figure 32 shows the SerDes reference clock input requirement for

AC-coupled connection scheme.

•

Single-ended mode

— The reference clock can also be single-ended. The SDn_REF_CLK input amplitude (single-ended swing) must be

between 400 and 800 mV peak-peak (from Vmin to Vmax) with SDn_REF_CLK either left unconnected or tied to

ground.

—The SDn_REF_CLK input average voltage must be between 200 and 400 mV. Figure 33 shows the SerDes

reference clock input requirement for single-ended signaling mode.

— To meet the input amplitude requirement, the reference clock inputs might need to be DC- or AC-coupled

externally. For the best noise performance, the reference of the clock could be DC- or AC-coupled into the unused

phase (SDn_REF_CLK) through the same source impedance as the clock input (SDn_REF_CLK) in use.

Figure 31. Differential Reference Clock Input DC Requirements (External DC-Coupled)

Figure 32. Differential Reference Clock Input DC Requirements (External AC-Coupled)

Figure 33. Single-Ended Reference Clock Input DC Requirements

n_REF_CLK

Vmax < 800 mV

Vmin > 0V

100 mV < Vcm < 400 mV

200 mV < Input Amplitude or Differential Peak < 800 mV

n_REF_CLK

Vcm

200mV < Input Amplitude or Differential Peak < 800 mV

Vmax < Vcm + 400 mV

Vmin > Vcm – 400 mV

n_REF_CLK

400 mV < SD

n_REF_CLK Input Amplitude < 800 mV

0 V

MPC8610EC Datasheet(PDF) 57 Page - NXP Semiconductors