ICS9214 Datasheet, PDF (12/16 Pages) Integrated Circuit Systems – Rambus XDR Clock Generator

Integrated
Circuit
Systems, Inc.
ICS9214
Input Clock Signal
The ICS9214 receives either a differential or single-ended reference clock (CLK_INT/C). When the reference input clock is
from a differential clock source, it must meet the voltage levels and timing requirements listed in the DC Characteristics –
Inputs and AC Characteristics – Inputs tables.
For a singled-ended clock input, an external voltage divider and a supply voltage, as shown in Figure 2, provide a reference
voltage VTH at the CLK_INC pin to determine the proper switching point for CLK_INT. The range of VTH is specified in the DC
Characteristics – Inputs table.
Swing Current
Control
ISET
R_RC
ODCLK_T
Differential Driver
ODCLK_C
V_TS
R₁
R₂
Measurement
Point
Z_CH
R₃
V_TS ^Measurement
Point
R₁
R₂
Z_CH
R₃
V_T
R_T
V_T
R_T
V(t)
Figure 2. Example System Clock Driver Equivalent Circuit
t_F
t_R
V_H
80%
20%
V_L
ODCLK_T
ODCLK_C
Figure 3. Input and Output Voltage Waveforms
Figure 4. Crossing-point Voltage
Vx+
Vx,nom
Vx-
0809G—08/02/08
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