ADC12 Operation
26-17
ADC12
26.2.9 ADC12 Grounding and Noise Considerations
As with any high-resolution ADC, appropriate printed-circuit-board layout and
grounding techniques should be followed to eliminate ground loops, unwanted
parasitic effects, and noise.
Ground loops are formed when return current from the A/D flows through paths
that are common with other analog or digital circuitry. If care is not taken, this
current can generate small, unwanted offset voltages that can add to or
subtract from the reference or input voltages of the A/D converter. The
connections shown in Figure 26−11 help avoid this.
In addition to grounding, ripple and noise spikes on the power supply lines due
to digital switching or switching power supplies can corrupt the conversion
result. A noise-free design using separate analog and digital ground planes
with a single-point connection is recommend to achieve high accuracy.
Figure 26−11.ADC12 Grounding and Noise Considerations
DVCC
DVSS
AVCC
AVSS
VeREF+
Digital
Power Supply
Decoupling
10 uF
100 nF
+
Using an External
Positive
Reference
VREF+
VREF− / VeREF−
Using the Internal
Reference
Generator
10 uF
100 nF
100 nF
+
+
10 uF
100 nF
+
Using an External
Negative
Reference
10 uF
+
Analog
Power Supply
Decoupling
10 uF
100 nF
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 ...