sx8725 Semtech Corporation, sx8725 Datasheet - Page 10

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

ADVANCED COMMUNICATIONS & SENSING
Circuit Description
General Description
The SX8725 is a complete low-power acquisition path with programmable gain, acquisition speed and
resolution.
Block Diagram
VREF
The internally generated V
stable voltage reference for the ZoomingADC.
This reference voltage is directly connected to one of the ZoomingADC reference multiplexer inputs.
The bandgap voltage stability is only guaranteed for V
2.4V, the bandgap voltage could reduce by up to 50mV.
The bandgap has relatively weak output drive so it is recommended that if the bandgap is required as a signal
input then PGA1 must be enabled with Gain = 1.
V1.5 © 2007 Semtech Corp.
D0/REF
D1/REF
AC2
AC3
OUT
IN
SX8725
V
REF
REF
+
-
is a trimmed bandgap reference with a nominal value of 1.22V that provides a
AC1
+
+
AC0
-
-
GPIO
Figure 3 - SX8725 Block Diagram
ZoomingADC™ for Pressure and Temperature Sensing
PGA
CHARGE
PUMP
CONTROL LOGIC
10
BATT
ZoomingADC
voltages of 3V and above. As V
4MHz
OSC
ADC
I
2
C
TM
BATT
www.semtech.com
READY
V
V
SDA
VSS
SCL
PUMP
BATT
drops down to
SX8725