Enhanced Analog-To-Digital Converter (Adc) Module - Texas Instruments TMS320C2810 Data Manual

www.ti.com
4.3

Enhanced Analog-to-Digital Converter (ADC) Module

A simplified functional block diagram of the ADC module is shown in
consists of a 12-bit ADC with a built-in sample-and-hold (S/H) circuit. Functions of the ADC module
include:
• 12-bit ADC core with built-in S/H
• Analog input: 0.0 V to 3.0 V (voltages above 3.0 V produce full-scale conversion results)
• Fast conversion rate: 80 ns at 25-MHz ADC clock, 12.5 MSPS
• 16-channel, MUXed inputs
• Autosequencing capability provides up to 16 "autoconversions" in a single session. Each conversion
can be programmed to select any 1 of 16 input channels
• Sequencer can be operated as two independent 8-state sequencers or as one large 16-state
sequencer (that is, two cascaded 8-state sequencers)
• Sixteen result registers (individually addressable) to store conversion values
– The digital value of the input analog voltage is derived by:
Digital Value
Digital Value
Digital Value
• Multiple triggers as sources for the start-of-conversion (SOC) sequence
– S/W – software immediate start
– EVA – Event manager A (multiple event sources within EVA)
– EVB – Event manager B (multiple event sources within EVB)
• Flexible interrupt control allows interrupt request on every end-of-sequence (EOS) or every other EOS
• Sequencer can operate in "start/stop" mode, allowing multiple "time-sequenced triggers" to synchronize
conversions
• EVA and EVB triggers can operate independently in dual-sequencer mode
• Sample-and-hold (S/H) acquisition time window has separate prescale control
The ADC module in the F281x and C281x has been enhanced to provide flexible interface to event
managers A and B. The ADC interface is built around a fast, 12-bit ADC module with a fast conversion
rate of 80 ns at 25-MHz ADC clock. The ADC module has 16 channels, configurable as two independent
8-channel modules to service event managers A and B. The two independent 8-channel modules can be
cascaded to form a 16-channel module. Although there are multiple input channels and two sequencers,
there is only one converter in the ADC module.
C281x ADC module.
The two 8-channel modules have the capability to autosequence a series of conversions, each module
has the choice of selecting any one of the respective eight channels available through an analog MUX. In
the cascaded mode, the autosequencer functions as a single 16-channel sequencer. On each sequencer,
once the conversion is complete, the selected channel value is stored in its respective RESULT register.
Autosequencing allows the system to convert the same channel multiple times, allowing the user to
perform oversampling algorithms. This gives increased resolution over traditional single-sampled
conversion results.
Copyright © 2001–2012, Texas Instruments Incorporated
Product Folder Link(s):
0,
=
Input Analog Voltage
4096
= ´
3
4095,
=
Submit Documentation Feedback
TMS320F2810 TMS320F2811 TMS320F2812 TMS320C2810 TMS320C2811 TMS320C2812
TMS320F2810, TMS320F2811, TMS320F2812
TMS320C2810, TMS320C2811, TMS320C2812
SPRS174T – APRIL 2001 – REVISED MAY 2012
when
ADCLO
-
when
when
Figure 4-4 shows the block diagram of the F281x and
Figure 4-4. The ADC module
input 0 V
£
0 V input 3 V
< <
input 3 V
³
Peripherals 63