max9963bjccq-td Maxim Integrated Products, Inc., max9963bjccq-td Datasheet - Page 20

• Manufacturer Part Number: max9963bjccq-td
• Description: Quad Low-power 500mbps Ate Driver/comparator
• Manufacturer: Maxim Integrated Products, Inc.

low-leakage mode, the bias current at DUT_ is further
reduced to less than 15nA, and signal tracking slows.
The nominal driver output resistance is 50Ω. Contact
the factory for different resistance values within the
45Ω to 51Ω range.
A pair of voltage clamps (high and low) can be config-
ured to limit the voltage at DUT_, and to suppress
reflections when the channel is configured as a high-
impedance receiver. The clamps behave as diodes
connected to the outputs of high-current buffers.
Internal circuitry compensates for the diode drop at
1mA clamp current. Set the clamp voltages using exter-
nal connections CPHV_ and CPLV_. The clamps are
enabled only when the driver is in the high-impedance
mode (Figure 2). For transient suppression, set the
clamp voltages to approximately the minimum and
maximum expected DUT_ voltage range. The optimal
clamp voltages are application specific and must be
empirically determined. If clamping is not desired, set
the clamp voltages at least 0.7V outside the expected
Table 3. Comparator Logic
Quad, Low-Power, 500Mbps
ATE Driver/Comparator
Figure 3. Open-Collector Comparator Outputs
20
CHV_
DUT_
CLV_
DUT_ > CHV_
______________________________________________________________________________________
0
0
1
1
V
V
DUT_ > CLV_
EE
EE
8mA
8mA
0
1
0
1
OPTIONAL
4 x 43Ω
CH_
0
0
1
1
7Ω
7Ω
Clamps
CH_
NCH_
CL_
NCL_
CL_
0
1
0
1
V
CCO
_ _
DUT_ voltage range; overvoltage protection remains
active without loading DUT_.
The MAX9963/MAX9964 have two independent high-
speed comparators for each channel. Each comparator
has one input connected internally to DUT_ and the
other input connected to either CHV_ or CLV_
(Figure 1). Comparator outputs are a logical result of
the input conditions, as indicated in Table 3.
Three configurations are available for the comparator
differential outputs to ease interfacing with a wide vari-
ety of logic families. An open-collector configuration
switches an 8mA current source between the two out-
puts. This configuration is available with and without
internal termination resistors connected to V
(Figure 3). For versions without internal termination
resistors, leave V
required external resistors. These resistors are typically
50Ω to the pullup voltage at the receiving end of the
output trace. Alternate configurations can be used, pro-
vided that the Absolute Maximum Ratings are not
exceeded. For versions with internal terminations, con-
nect V
provides a nominal 400mV
termination.
Figure 4. Open-Emitter Comparator Outputs
DUT_
CHV_
CLV_
CCO_ _
to the desired V
CCO_ _
100Ω
100Ω
100Ω
100Ω
unconnected and add the
P-P
OH
swing and 50Ω source
voltage. Each output
Comparators
CH_
NCH_
CL_
NCL_
V
CCO_ _
CCO
_ _