Texas Instruments ADS1202, User Manual

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3-1 EVM Operation
EVM Operation
The analog input source can be applied directly to J1 pins 2 and 4. Series
resistors R10 and R11 as well as capacitors C8, C9, and C10 provide filtering
to the input of the ADS1202.
The digital control signals can be applied directly to J2 (top or bottom side). The
ADS1202 modular EVM can also be connected directly to a DSP interface
board.
Footprints are provided on the PWB which allow a variety of isolation options.
Transformers, optoisolators or optocouplers may be installed for evaluation of
different isolation techniques.
The EVM uses two solder shorts at position U3 to provide direct nonisolated
operation of the ADS1202, for isolated operation, these shorts may be
replaced with isolation devices such as the IL711 from NVE (close W3 pins
2 - 3), HCPL - 2631 optocouplers (close W3 pins 1 - 2) or transformer circuits
such as those described in application note SLAA096.
The operating mode of the ADS1202 can be controlled by placing shunt
jumpers on W1 and W2. When the jumper is open (not installed) logic 1 is
applied to the mode pins. W1 controls M0, W2 controls M1. The EVM is
configured with both W1 and W2 closed, providing Mode 0 operation.
Jumper
W1 W2
Description
closed closed
Mode 0 operation – processor reads MDAT on rising clock
edge only
open closed
Mode 1 operation – processor reads MDAT on every clock
edge
closed open Mode 2 operation – Manchester decoding required
open open
Mode 3 operation – requires external clock ( optional - short
TP1 to TP7)
To verify the ADS1202EVM is functional, arrange W1 and W2 for Mode 0
operation by ensuring the shunt jumpers are installed (factory default
conditions). Apply 5-V power to the EVM through J3. Apply a 200-kHz
sinusoidal wave (250 mV
PP
) to J1.2 referenced to J1.4.
Chapter 3