TWR-K60N512-KEIL Freescale Semiconductor, TWR-K60N512-KEIL Datasheet - Page 167

• Manufacturer Part Number: TWR-K60N512-KEIL
• Description: K60N512 Keil Tower Kit
• Manufacturer: Freescale Semiconductor
• Series: Kinetisr
• Type: MCUr

Specifications of TWR-K60N512-KEIL

• Rohs Compliant: YES
• Contents: 4 Boards, Documentation, DVD
• Peak Reflow Compatible (260 C): Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: Freescale Tower System, K60N512

Chapter 18
Using Peripheral Delay Block (PDB) to Schedule
Analog to Digital Converter (ADC) Conversions
18.1 Overview
This chapter will demonstrate how to use the PDB module to schedule and perform ADC
conversions of the analog voltage available from the on-board demonstration
potentiometer. The application will sense the potentiometer control and report it over the
serial port.
The code example shows how to:
Calibration of the ADC is also illustrated.
18.1.1 Introduction
Timing of ADC conversions relative to system events is a key to applications, such as
motor control, and metering, requiring timing of ADC conversions for the best time to get
a noise-reduced reading.
When the Kinetis MCU is acting as a controller, it will output control changes from time
to time. Scheduling ADC conversions around these changes, which may make transient
disturbances in the system, is key.
Scheduling the ADC conversions at a time after the transient effects of the last control
change has been made can enable smooth operation of control loops. The PDB allows
simple scheduling of one or both of the ADC peripherals conversions.
Freescale Semiconductor
• Make a low-level driver for the ADC
• Configure the ADC for averaging a single-ended voltage conversion
• Use the bus clock to clock the ADC
• Use a simple exponential filter on the averaged results
• Have the ADC conversions scheduled at time intervals determined by the PDB
module
Kinetis Quick Reference User Guide, Rev. 0, 11/2010
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