SX8723CWLTDT SEMTECH [Semtech Corporation], SX8723CWLTDT Datasheet - Page 18

• Manufacturer Part Number: SX8723CWLTDT
• Description: ZoomingADC for sensing data acquisition
• Manufacturer: SEMTECH [Semtech Corporation]

Revision 1.01
© Semtech
7 ZoomingADC
7.1 Overview
The ZoomingADC is a complete and versatile low-power analog front-end interface typically intended for sensing
applications. In the following text the ZoomingADC will be referred as ZADC.
The key features of the ZADC are:
The total acquisition chain consists of an input multiplexer, 3 programmable gain amplifier stages and an over sampled
A/D converter. The reference voltage can be selected on two different channels. Two offset compensation amplifiers
allow for a wide offset compensation range. The programmable gain and offset allow the application to zoom in on a
small portion of the reference voltage defined input range.
7.1.1 Acquisition Chain
Figure 10, page 18
Figure
Oscillator.
Analog inputs can be selected through an 8 input multiplexer, while reference input is selected between two
differential channels. It should however be noted that only 7 acquisition channels (including the V
when configured as single ended since the input amplifier is always operating in differential mode with both positive
and negative input selected through the multiplexer.
ADVANCED COMMUNICATIONS & SENSING
Analog
Inputs
Reference
Inputs
Programmable 6 to 16-bit dynamic range over-sampled ADC
Flexible gain programming between 1/12 and 1000
Flexible and large range offset compensation
Differential or single-ended input
2-channel differential reference inputs
Power saving modes
10) manages all communications with the I2C peripheral. The clocking is derived from the internal 4 MHz
V
V
AC
AC
AC
AC
N.C.
N.C.
V
V
V
V
SS
REF
BATT
SS
REF
SS
2
3
4
5
shows the general block diagram of the acquisition chain (AC). A control block (not shown in
AMUX
VMUX
January 2011
V
REF,ADC
Figure 10. ZADC General Functional Block Diagram
S
±
Vin
V
IN
PGA1
Page 18
ANALOG ZOOM
±
±
V
Vin
Voff
ZoomingADC for sensing data acquisition
D1
PGA2
±
±
Vin
Voff
V
D2
PGA3
www.semtech.com/products/
SX8723C
REF
DATASHEET
) are available
±
±
Vin
Vref
V
IN,ADC
ADC