Datasheet

LPC408X_7X All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 3.1 — 1 September 2014 63 of 138
NXP Semiconductors
LPC408x/7x
32-bit ARM Cortex-M4 microcontroller
• Buffered output.
• Power-down mode.
• Selectable output drive.
• Dedicated conversion timer.
• DMA support.
7.21 Comparator
Remark: The comparator is available on parts LPC4088/7876.
Two embedded comparators are available to compare the voltage levels on external pins
or against internal voltages. Up to four voltages on external pins and several internal
reference voltages are selectable on each comparator. Additionally, two of the external
inputs can be selected to drive an input common on both comparators.
7.21.1 Features
• Up to five selectable external sources per comparator; fully configurable on either
positive or negative comparator input channels.
• 0.9 V internal band gap reference voltage selectable as either positive or negative
input on each comparator.
• 32-stage voltage ladder internal reference for selectable voltages on each
comparator; configurable on either positive or negative comparator input.
• Voltage ladder source voltage is selectable from an external pin or the 3.3 V analog
voltage supply.
• Voltage ladder can be separately powered down for applications only requiring the
comparator function.
• Relaxation oscillator circuitry output, for a 555 style timer operation.
• Individual comparator outputs can be connected to I/O pins.
• Separate interrupt for each comparator.
• Edge and level comparator outputs connect to two timers allowing edge counting
while a level match has been asserted or measuring the time between two voltage trip
points.
7.22 UART0/1/2/3 and USART4
Remark: UART0/1/2/3 are available on all parts. USART4 is available on parts
LPC4088/78/76.
The LPC408x/7x contain five UARTs. In addition to standard transmit and receive data
lines, UART1 also provides a full modem control handshake interface and support for
RS-485/9-bit mode allowing both software address detection and automatic address
detection using 9-bit mode.
The UARTs include a fractional baud rate generator. Standard baud rates such as
115200 Bd can be achieved with any crystal frequency above 2 MHz.
7.22.1 Features
• Maximum UART data bit rate of 7.5 MBit/s.