ADC14C105EB/NOPB National Semiconductor, ADC14C105EB/NOPB Datasheet - Page 5

• Manufacturer Part Number: ADC14C105EB/NOPB
• Description: BOARD EVAL 14-BIT ADC14C105
• Manufacturer: National Semiconductor
• Series: PowerWise®r

Specifications of ADC14C105EB/NOPB

• Number Of Adc's: 1
• Number Of Bits: 14
• Sampling Rate (per Second): 105M
• Data Interface: Parallel
• Inputs Per Adc: 1 Differential
• Input Range: 2 Vpp
• Power (typ) @ Conditions: 400mW @ 105MSPS
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: ADC14C105
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: ADC14C105EB

For input frequencies below 70MHz the circuit of Figure 4
may be used.
4.2 ADC reference circuitry
The ADC14C105 can use an internal or external 1.2V
reference. This Evaluation Board is configured to use the
internal reference.
4.3 ADC clock circuit
Solder jumpers are used to select the path of the clock to
the ADC. While not as convenient as pin-type jumpers,
these introduce less distortion into the clock signal.
Care must be taken to provide a high quality low jitter
clock source. The board has a Pletronics SM7745 or
Vectron VCC1 type device crystal clock. It is buffered by
U11 (NS7WV125) and applied to the ADC’s clock input
pin.
The user can configure the board for an external clock at
connector J10. For this option short the pins of solder
jumper JP52 and open the pins of JP45. It may also be
necessary to remove L2 so the crystal is not powered.
Refer to the schematic for more detail.
4.4 Digital Data Output
The digital output data is available at pins B4 (MSB)
through B17 of the WaveVision™ (WV4) connector J5.
4.5 Data Format/ Duty Cycle Stabilizer
Output data format and the duty cycle stabilizer (DCS)
are controlled by jumper JP23.
Shorting pins 1-2 of JP23 sets the output format to 2’s
complement with DCS Off.
Shorting pins 3-4 of JP23 sets the output format to 2’s
complement with DCS On.
Shorting pins 5-6 of JP23 sets the output format to offset
binary with DCS On.
Shorting pins 7-8 of JP23 sets the output format to offset
binary with DCS Off. This is the default setting.
V
Figure 4. Analog Input Network for F
IN
0.1 µF
50Ω
0.1 µF
ADT1-1WT
0.1 µF
18 pF
20Ω
20Ω
V
CMO
IN
< 70MHz
Input
ADC
5
4.6 Power Supply Connections
Power to this board is supplied through power connector
J1. The only supply needed is +5V at pin 2 plus ground at
pin 1.
Voltage and current requirements for the ADC14C105
Evaluation Board are:
5.0 Installing the ADC14C105 Evaluation Board
The evaluation board requires power supplies as
described in Section 4.6. An appropriate signal source
should be connected to the Signal Input SMA connector
J9.
appropriate signal generator (such as the HP8644B or the
R&S SME-03) with 50 Ohm source impedance should be
connected to the Analog Input connector through an
appropriate bandpass filter as even the best signal
generator available can not produce a signal pure enough
to evaluate the dynamic performance of an ADC.
If this board is used in conjunction with the the
WaveVision™ 4.0 Digital Interface Board and
WaveVision™ software, a USB must be connected
between the Digital Interface Board and the host. See
the WaveVision™ 4.0 Digital Interface Board manual for
details.
•
+5.0V at 500 mA
When
evaluating
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dynamic
performance,
an