sx8725 Semtech Corporation, sx8725 Datasheet - Page 31

• Manufacturer Part Number: sx8725
• Description: Sx8725 Zoomingadc? For Pressure And Temperature Sensing
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & SENSING
Mode Register
Note1:
Note2:
V1.5 © 2007 Semtech Corp.
7
6
5:4
3
2
1
0
Bit
MULT_READY
MULT_ACTIVE
CHOP
MULT_FORCE_ON
MULT_FORCE_OFF
VREF_D0_OUT
VREF_D1_IN
Name
The chop control is to allow chopping of the internal bandgap reference. This may be useful to help eliminate bandgap
related internal offset voltage and 1/f noise. The bandgap chop state may be forced High or Low, or may be set to toggle
during conversion at either the same rate or half the rate of the Elementary Conversion. (See Conversion Sequence in the
ZoomingADC description)
The internal charge pump may be forced On or Off to avoid conversion interruptions due to the pump switching off and on
when the V
sufficient supply to the ADC. If the ADC is not being run at full rate or full accuracy then it may operate sufficiently well
when V
BATT
BATT
is less than 3V.
supply is near 3V. If the pump is on automatic, then it will activate when V
r
r
rw
rw
rw
rw
rw
Mode
1
0
00
0
1
0
0
ZoomingADC™ for Pressure and Temperature Sensing
Reset
Table 29 - RegMode (0x70)
1: Indicates that the charge pump has settled and the output voltage is
sufficient for conversion
1: Indicates that the charge pump is running (either because VBATT<3V
or it has been forced on)
VREF chopping control
11: Chop at Nelconv/2 rate
10: Chop at Nelconv rate
01: Chop state = 1
00: Chop state = 0
(Note 1)
Force charge pump On (takes priority) (Note 2)
Force charge pump Off (Note 2)
Enable VREF output on D0 pin
Enable VREF input on D1 pin
31
Function
BATT
drops below 3V to ensure
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SX8725