Datasheet

Using the THS7002 EVM
1-12
General Information
1.6 Using the THS7002 EVM
The THS7002 EVM operates from a split power supply with voltages ranging
from ±5 V to ±15 V. It also uses 5 volt logic control signals to configure the
operation of the EVM when the DIP switches are used. The use of a single
supply for this EVM is not recommended. As shipped, the preamplifiers are set
to a gain of 2 and the EVM is configured for a single-ended input that uses the
preamplifiers to directly drive the PGA stages. An oscilloscope is typically used
to view and analyze the EVM output signals.
1) Ensure that all power supplies are set to
OFF before making power supply
connections to the THS7002 EVM.
2) Select the operating voltage for the EVM and connect appropriate split
power supplies to the banana jacks on the module marked
+V
CC
(J1) and
–V
CC
(J3).
3) Connect a 5-V power supply to the banana jack marked +5 V (J4).
4) Connect all power supply grounds to the banana jack marked GND (J2).
5) Connect an oscilloscope probe to the PGA–A amplifier output BNC (J9).
Connecting directly to J9 with a 50-Ω nominal impedance cable and probe
is not recommended. The output drive capability of the PGAs is very
limited. Such a connection will load the output excessively, reducing the
output voltage range of the amplifier and is not a true measurement of the
amplifier performance.
6) Set EVM jumpers as shown in Table 1–3.
Table 1–3.THS7002 EVM Jumper Settings
JP1 JP2 JP3 JP4 JP5
2–3 2–3 1–2 2–3 1–2
7) Set DIP switch 1 and 2 elements as shown in Table 1–4.
Table 1–4.THS7002 EVM DIP Switch Settings
SWITCH S1 LABEL POSITION SWITCH S2 LABEL POSITION
S1:A A–G0 0 S2:A B–G2 1
S1:B A–G1 0 S2:B B–G1 0
S1:C A–G2 1 S2:C B–G0 0
S1:D A–S/D 0 S2:D B–S/D 0
S1:E A–VREF 1 S2:E B–VREF 1
S1:F VL 1 S2:F VH 1
8) Set the power supplies to ON .
9) Connect a signal input to the INPUT A BNC (J6).
Note that each input connector on this EVM is terminated with a 50-Ω resistor
to ground. With a 50-Ω source impedance, the voltage seen by the THS7002
amplifier IC on the EVM will be the source signal voltage applied to the EVM
input connector.
10) Verify the output signal on the oscilloscope using a high-impedance probe
— a voltage gain of approximately 2.5 to 1 should be observed.