SD16 Operation
27-5
SD16
27.2.5 Analog Input Pair Selection
Each SD16 channel can convert up to 8 differential input pairs multiplexed into
the PGA. Up to six input pairs (A0-A5) are available externally on the device.
See the device-specific data sheet for analog input pin information. An internal
temperature sensor is available to each channel using the A6 multiplexer
input. Input A7 is a shorted connection between the + and - input pair and can
be used to calibrate the offset of each SD16 input stage.
Analog Input Setup
The analog input of each channel is configured using the SD16INCTLx
register. These settings can be independently configured for each SD16
channel.
The SD16INCHx bits select one of eight differential input pairs of the analog
multiplexer. The gain for each PGA is selected by the SD16GAINx bits. A total
of six gain settings are available.
During conversion any modification to the SD16INCHx and SD16GAINx bits
will become effective with the next decimation step of the digital filter. After
these bits are modified, the next three conversions may be invalid due to the
settling time of the digital filter. This can be handled automatically with the
SD16INTDLYx bits. When SD16INTDLY = 00h, conversion interrupt requests
will not begin until the 4
th
conversion after a start condition.
An external RC anti-aliasing filter is recommended for the SD16 to prevent
aliasing of the input signal. The cutoff frequency should be < 10 kHz for a
1-MHz modulator clock and OSR = 256. The cutoff frequency may set to a
lower frequency for applications that have lower bandwidth requirements.
Summary of Contents for MSP430x4xx Family
Page 1: ...MSP430x4xx Family 2007 Mixed Signal Products User s Guide SLAU056G ...
Page 2: ......
Page 6: ...vi ...
Page 114: ...3 76 RISC 16 Bit CPU ...
Page 304: ...5 20 FLL Clock Module ...
Page 340: ...7 8 Supply Voltage Supervisor ...
Page 348: ...8 8 16 Bit Hardware Multiplier ...
Page 372: ...9 24 32 Bit Hardware Multiplier ...
Page 400: ...10 28 DMA Controller ...
Page 428: ...13 10 Basic Timer1 ...
Page 466: ...15 24 Timer_A ...
Page 522: ...17 30 USART Peripheral Interface UART Mode ...
Page 544: ...18 22 USART Peripheral Interface SPI Mode ...
Page 672: ...23 12 Comparator_A ...
Page 692: ...24 20 LCD Controller ...
Page 746: ...26 28 ADC12 ...