sx8724s Semtech Corporation, sx8724s Datasheet - Page 15

• Manufacturer Part Number: sx8724s
• Description: Zoomingadc For Sensing Data Acquisition
• Manufacturer: Semtech Corporation

Revision 1.0
© Semtech
6.3.1 Optional Operating Mode: External Vref
D0 and D1 are multi-functional pins with the following functions in different operating modes (see RegMode register
for control settings):
This allows external monitoring of the internal bandgap reference or the ability to use an external reference input for
the ADC, or the option to filter the internal V
V
any value between 0V and V
ADVANCED COMMUNICATIONS & SENSING
REF
D0/VREF
D0/VREF
D1/VREF
D1/VREF
Figure 9. D1 is Digital Input / Output and D0 Reference
is a trimmed as ADC reference with a nominal value of 1.22V. When using an external V
Figure 7. D0 and D1 are Digital Inputs / Outputs
OUT
OUT
IN
IN
reference
reference
Bandgap
Bandgap
Internal
Internal
+
-
+
-
Voltage Output
RegMode[1] = 0
V
V
RegMode[1] = 1
BG
BG
February 2011
0
1
0
1
BATT
. Simply substitute the external value for 1.22 V in the ADC conversion calculations.
RegMode[0] = 0
RegMode[0] = 0
0
1
1
0
0
1
1
0
V
V
REF
REF
REF
GPIO
ZoomingADC
GPIO
GPIO
ZoomingADC
GPIO
output before feeding back as V
Page 15
D0/VREF
D0/VREF
D1/VREF
D1/VREF
Figure 8. D1 is Reference Voltage Input and D0 is Digital
Figure 10. D0 is Reference Voltage Output and D1 is
ZoomingADC for sensing data acquisition
OUT
OUT
IN
IN
reference
reference
Bandgap
Bandgap
Internal
Internal
Reference Voltage Input
REF,ADC
+
+
-
-
RegMode[1] = 1
V
RegMode[1] = 0
Input / Output
BG
0
1
0
1
input. The internally generated
REF,ADC
RegMode[0] = 1
RegMode[0] = 1
SX8724S
0
1
1
0
0
1
1
0
input, it may have
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DATASHEET
V
V
REF
REF
GPIO
ZoomingADC
GPIO
GPIO
ZoomingADC
GPIO