Datasheet

W3
3
2
1
THS56x1A
EXTLO
5 VA
EXTIO
BIAS
R14
www.ti.com Generating a Voltage Reference
Figure 3-4. Jumper Configuration for Internal Reference Voltage
3.5.2 Onboard External Reference
To select the onboard external reference voltage, the user should follow the jumper configuration shown in
Table 3-6.
Table 3-6. Jumper Configuration for External VREF
Jumper Pins 1 and 2 Pins 2 and 3
VREF setting
W3 Jumper not installed N/A
W4 Jumper installed Jumper not installed
It is important to understand that the reference voltage plays a fundamental part in the conversion
process. Changes in the value of the reference voltage are reflected in the full-scale range of the device.
The variation in voltage for the reference should, ideally, contribute less than 1/2 an LSB of error to the
total conversion process.
External reference voltages can be supplied via W4; see Table 3-5 for details.
29
SLAU032C– February 2001– Revised April 2011 User Configurations
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