Adc12 Control Block Diagram; Adc12 Overview - Texas Instruments UCD3138 Technical Reference Manual

The ADC 12 in UCD3138 digital controller is a 12 bit, high speed analog to digital converter. It comes
equipped with the following features:
• Typical conversion speed of 267 ksps
• Conversions can range from 1 to 16 ADC channel conversions in any desired sequence
• Post conversion averaging capability, ranging from 4X, 8X, 16X or 32X samples
• Configurable triggering for ADC conversions from the following sources: firmware, DPWM rising edge,
ADC_EXT_TRIG pin or Analog Comparator results
• Interrupt capability to embedded processor at completion of ADC conversion
• Six digital comparators on the first 6 channels of the conversion sequence using either raw ADC data
or averaged ADC data
• Two 10 µA current sources for excitation of PMBus addressing resistors
• Dual sample & Hold for accurate power measurement
• Internal temperature sensor for temperature protection and monitoring.
The control module, shown in
series of conversions. The sequencing is fully configurable for any combination of 16 possible ADC
channels through an analog multiplexer embedded in the ADC12 block. Once converted, the selected
channel value is stored in the result register associated with the sequence number. Input channels can be
sampled in any desired order or programmed to repeat conversions on the same channel multiple times
during a conversion sequence. Selected channel conversions are also stored in the result registers in
order of conversion, where the result 0 register is the first conversion of a 16-channel sequence and result
15 register is the last conversion of a 16-channel sequence. The number of channels converted in a
sequence can vary from 1 to 16.
16 ADC
Channels
Unlike the EADC converters in the Digital Power Peripherals portion of UCD3138, which feature a
substantially faster conversion rate and hence are primarily designed for closing high speed
voltage/current feedback loops of the power supply, the ADC12 is not usually used for loop compensation
purposes. The ADC12 features make it best suited for monitoring and detection of currents, voltages,
temperatures and faults.
SNIU028A – February 2016 – Revised April 2016
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Figure 8-1, contains the control and conversion logic for auto-sequencing a
ADC12 Block ADC12 Block
12-bit 12-bit 12-bit
S/H S/H
SAR SAR SAR
ADC ADC ADC
ADC Channel[15:0] ADC Channel[15:0]
DPWM DPWM
Modules Modules
Figure 8-1. ADC12 Control Block Diagram
Copyright © 2016, Texas Instruments Incorporated
SNIU028A – February 2016 – Revised April 2016

ADC12 Overview

ADC12 Registers ADC12 Registers
ADC ADC
Averaging Averaging
ADC12 ADC12
Control Control
Digital Digital
Comparators Comparators
ADC External Trigger (from pin) ADC External Trigger (from pin)
Analog Analog
Comparators Comparators
Chapter 8
297
ADC12 Overview