TC1797_14 Datasheet, PDF (58/192 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

TC1797
Introduction
As shown in Figure 14, the main FADC functional blocks are:
• An Input Structure containing the differential inputs and impedance control.
• An A/D Converter Stage responsible for the analog-to-digital conversion including an
input multiplexer to select between the channel amplifiers
• A Data Reduction Unit containing programmable anti-aliasing and data reduction
filters
• A Channel Trigger Control block determining the trigger and gating conditions for the
FADC channels
• A Channel Timer for each channel to independently trigger the conversions
• An A/D Control block responsible for the overall FADC functionality
FADC Power Supply and References
The FADC module is supplied by the following power supply and reference voltage lines:
• V_DDMF / V_SSMF: FADC Analog Channel Amplifier Power Supply (3.3 V)
• V_DDIF / V_SSMF: FADC Analog Input Stage Power Supply (3.3 - 5 V),
the V_DDIF supply does not appear as supply pin, because it is internally connected to
the V_DDM supply of the ADC that is sharing the FADC input pins.
• V_DDAF / V_SSAF: FADC Analog Part Power Supply (1.5 V),
to be fed in externally
• V_FAREF / V_FAGND: FADC Reference Voltage (3.3 V max.) and FADC Reference Ground
Input Structure
The input structure of the FADC in the TC1797 contains:
• A differential analog input stage for each input channel to select the input impedance
(differential or single-ended measurement) and to decouple the FADC input signal
from the pins.
• Input channels 2 and 3 are overlaid with ADC1 input signals (AN28, AN29, AN30,
AN31), whereas input channels 0 and 1 are available on dedicated input pins (AN32,
AN33, AN34, AN35).
• A channel amplifier for each input channel with a settling time (about 5µs) when
changing the characteristics of an input stage (changing between unused,
differential, single-ended N, or single-ended P mode).
Data Sheet
54
V1.3, 2014-08