Texas Instruments THS1030/31EVM, User Manual

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Purpose
1-2
1.1 Purpose
The THS1030/31EVM evaluation module (EVM) provides a platform for
evaluation of the THS1030 and THS1031 10-bit analog-to-digital converters
(ADC) under various signal, reference, and supply conditions. Unless stated
explicitly, the functionality described in this user’s guide applies to both
THS1030 and THS1031 devices.
1.2 EVM Basic Functions
Analog input to the THS1030/31 is provided via an external SMA connector.
The input can be configured onboard to be ac, dc, or transformer coupled to
the input of the device.
An external SMA connector is provided on the THS1031 for the clamp input.
This allows external digital control of the ADC’s clamping function. The ADC
can be clamped to either the device reference or to ground via an onboard
jumper.
The EVM provides an external SMA connection for ADC clock input. This can
be configured to be either ac or dc coupled. Space is reserved on the board
for a crystal oscillator to perform this function, and can be populated when re-
quired.
In addition to the internal reference from the THS1030/31 device, options are
provided on the EVM to allow adjustment of the ADC reference via an onboard
reference circuit.
Output from the EVM is via a 40-pin header connector. The digital lines from
the THS1030/31 are buffered using the SN74LVCC4245A before going to the
header. This allows the THS1030/31 supplies to be varied without affecting the
output signal levels.
Power connections to the EVM are via 4-mm banana sockets. Separate input
connectors are provided for the analog and digital supply to the device, and
for the reference and output buffer circuits.
The THS1031 has a number of programmable registers that can be pro-
grammed using DIL switches on the EVM.
1.3 Power Requirements
The EVM has 4 dc-power supply connections: 5 V for the output buffers, 2.7 V
to 5 V for the analog and digital supplies to the ADC, and 2.7 V to 5 V for the
reference circuit. Each of these supplies is independent, but it should be noted
that the input thresholds of the ADC will vary dependent on the digital and ana-
log supply voltages, as per the datasheet specification.