3. Hardware Description: Parts and Circuits
32-bit MCU Current Sensing Board Design Guide
8
3.2
24-Bit Analog to Digital Converter (LTC2400)
The 24-bit Analog to Digital Converter is used to convert the precision analog voltage signal to digital
signal. Small voltage signal across the small Shunt (Sensing) resistor is sensed to measure the exact
micro current.
For detailed information of this part, please refer to LTC2400 Technical Document.
Figure 4. 24-bit ADC (LTC2400) Block Diagram
Figure 4 shows a basic circuit configuration of the 24-bit ADC. Users who use this part for circuit designs
and software (SPI communication) configuration need to consider the followings:
1.
A bypass capacitor of 1uF should be placed close to the power supply unit.
2.
The reference voltage range of the ADC can be determined by using V
REF
. If users want the
input range of the ADC from 0V to 3.3V, users need to apply the V
REF
= 3.3V.
3.
F
0
in Figure 4 can be used with 3 alternative functions. In the example circuit in Figure 4, F
0
is
connected to GND to use an internal OSC of the LTC2400 and a notch filter of 60Hz.
