XTR111_14 Datasheet, PDF (15/33 Pages) Texas Instruments – Precision Voltage-to-Current Converter/Transmitter

XTR111
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DYNAMIC PERFORMANCE
The rise time of the output current is dominated by
the gate capacitance of the external FET.
The accuracy of the current mirror relies on the
dynamic matching of multiple individual current
sources. Settling to full resolution may require a
complete cycle lasting around 100μs. Figure 39
shows an example of the ripple generated from the
individual current source values that average to the
specified accuracy over the full cycle.
SBOS375C – NOVEMBER 2006 – REVISED JUNE 2011
The output glitch magnitude depends on the
mismatch of the internal current sources. It is
approximately proportional to the output current level
and scales directly with the load resistor value. It will
differ slightly from part to part. The effects of filtering
the output are shown in Figure 40 and Figure 41.
External FET
No Filter
500W
20ms/div
Figure 39. Output Noise without Filter into 500Ω
External FET
Load Capacitor
C_F
10nF
500W
20ms/div
Figure 40. Output with 10nF Parallel to 500Ω
Copyright © 2006–2011, Texas Instruments Incorporated
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