Rainbow Electronics MAX104 User Manual
Page 19
-10dBm (100mV clock signal amplitude) to +10dBm
(1V clock signal amplitude). The MAX104 dynamic per-
formance specifications are determined by a single-
ended clock drive of +4dBm (500mV clock signal
amplitude). To avoid saturation of the input amplifier
stage, limit the clock power level to a maximum of
+10dBm.
Differential Clock Inputs (Sine-Wave Drive)
The advantages of differential clock drive (Figure 13b,
Table 5) can be obtained by using an appropriate
balun or transformer to convert single-ended sine-wave
sources into differential drives. The precision on-chip,
laser-trimmed 50
Ω
clock-termination resistors ensure
excellent amplitude matching. Refer to
Single-Ended
Clock Inputs (Sine-Wave Drive)
for proper input ampli-
tude requirements.
Single-Ended Clock Inputs (ECL Drive)
Configure the MAX104 for single-ended ECL clock drive
by connecting the clock inputs as shown in Figure 13c
(Table 5). A well bypassed V
BB
supply (-1.3V) is essen-
tial to avoid coupling noise into the undriven clock input,
which would degrade dynamic performance.
Differential Clock Inputs (ECL Drive)
The MAX104 may be driven from a standard differential
(Figure 13d, Table 5) ECL clock source by setting the
clock termination voltage at CLKCOM to -2V. Bypass
the clock-termination return (CLKCOM) as close as
possible to the ADC with a 0.01µF capacitor connected
to GNDI.
AC-Coupling Clock Inputs
The clock inputs CLK+ and CLK- can also be driven
with positive referenced ECL (PECL) logic if the clock
MAX104
±5V, 1Gsps, 8-Bit ADC with
On-Chip 2.2GHz Track/Hold Amplifier
______________________________________________________________________________________
19
CLK+
CLK- = 0V
+0.5V
-0.5V
NOTE: CLKCOM = 0V
t
Figure 13a. Single-Ended Clock Input Signals
CLK+
-0.8V
-1.8V
t
CLK- = -1.3V
NOTE: CLKCOM = -2V
Figure 13c. Single-Ended ECL Clock Drive
CLK+
CLK-
+0.5V
-0.5V
t
NOTE: CLKCOM = 0V
Figure 13b. Differential Clock Input Signals
CLK+
CLK-
-0.8V
-1.8V
t
NOTE: CLKCOM = -2V
Figure 13d. Differential ECL Clock Drive