Datasheet

LPC15XX All information provided in this document is subject to legal disclaimers. © NXP B.V. 2014. All rights reserved.
Product data sheet Rev. 1 — 19 February 2014 40 of 99
NXP Semiconductors
LPC15xx
32-bit ARM Cortex-M3 microcontroller
8.24.1 Features
• 12-bit successive approximation analog-to-digital converter.
• 12-bit conversion rate of 2 MHz.
• Input multiplexing among 12 pins and up to 4 internal sources.
• Internal sources are the temperature sensor voltage, internal reference voltage, core
voltage regulator output, and VDDA/2.
• Two configurable conversion sequences with independent triggers.
• Optional automatic high/low threshold comparison and zero-crossing detection.
• Power-down mode and low-power operating mode.
• Measurement range VREFN to VREFP (typically 3 V; not to exceed VDDA voltage
level).
• Burst conversion mode for single or multiple inputs.
• Synchronous or asynchronous operation. Asynchronous operation maximizes
flexibility in choosing the ADC clock frequency, Synchronous mode minimizes trigger
latency and can eliminate uncertainty and jitter in response to a trigger.
8.25 Digital-to-Analog Converter (DAC)
The DAC supports a resolution of 12 bits. Conversions can be triggered by an external pin
input or an internal timer.
The DAC includes an optional automatic hardware shut-off feature which forces the DAC
output voltage to zero while a HIGH level on the external DAC_SHUTOFF pin is detected.
8.25.1 Features
• 12-bit digital-to-analog converter.
• Supports DMA.
• Internal timer or pin external trigger for staged, jitter-free DAC
conversion sequencing.
• Automatic hardware shut-off triggered by an external pin.
8.26 Analog comparator (ACMP)
The LPC15xx include four analog comparators with seven selectable inputs each for each
positive or negative input channel. Two analog inputs are common to all four comparators.
Internal voltage inputs include a voltage ladder reference with selectable voltage supply
source, the temperature sensor or the internal voltage reference.
The analog inputs to the comparators are fixed-pin functions and must be enabled through
the switch matrix.
The outputs of each analog comparator are internally connected to the ADC trigger inputs
and to the SCT inputs, so that the result of a voltage comparison can trigger a timer
operation or an analog-to-digital conversion.