PAC5250_17 Datasheet, PDF (46/70 Pages) Active-Semi, Inc – Power Application Controller

PAC5250
Power Application Controller
13. ADC WITH AUTO-SAMPLING SEQUENCER
13.1. Block Diagram
Figure 13-1. ADC with Auto-Sampling Sequencer
ADC WITH AUTO-SAMPLING SEQUENCER
DAxP
DAxN
ADx
CONFIGURABLE ANALOG FRONT END
DIFFERENTIAL PGA
S/H
DIFF-PGA
V , V , V /2
TEMP MON REF
ADC RESULT REGISTERS
(16)
RRREREEGEGGIGSISISITSTTETEERERRR
ADC
10-BIT
ADC
AUTO-SAMPLING
SEQUENCER
STATE MACHINE 0
STATE MACHINE 1
EMUX CONTROL
EMUX
13.2. Functional Description
13.2.1. ADC
The analog-to-digital converter (ADC) is a 10-bit succesive approximation register (SAR) ADC with 1 μs conversion
time and up to 1MSPS capability. The ADC input clock has a user-configurable divider from /1 to /8 of the system clock.
The integrated analog multiplexer allows selection from up to 6 direct ADx inputs, and from up to 10 analog inputs signals
in the Configurable Analog Front End (CAFE), including up to 3 differential input pairs. The ADC can be configured for
repeating or non-repeating conversions and can interrupt the microcontroller when a conversion is finished.
13.2.2. Auto-Sampling Sequencer
Two independent and flexible auto-sampling sequencer state machines allow signal sampling using the ADC without
interaction from microcontroller core. Each auto-sampling sequencer state machine can be programmed to take and store up
to 8 samples each in the ADC result register from different analog inputs, able to control the ADC MUX and ADC Premux
as well as the precise timing of the S/H in the Configurable analog front end. The sampling start of the auto-sampling
sequencer can be precisely triggered using timers A, B, C, or D or any of their associated PWM edges (high-to-low or low-
to-high). It also supports manual start or a ping-pong-scheme, where one auto-sampling sequencer state machine triggers
the other when it finishes sampling.
The auto-sampling sequencer can interrupt the microcontroller when either conversion sequence is finished.
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Rev 1.7‒April 15, 2016