LPC1777 View Datasheet(PDF) - NXP Semiconductors.
Part Name
Description
MFG CO.
LPC1777
NXP Semiconductors.
'LPC1777' PDF : 120 Pages View PDF
NXP Semiconductors
LPC178x/7x
32-bit ARM Cortex-M3 microcontroller
The first option assumes that power consumption is not a concern and the design ties the
VDD(3V3) and VDD(REG)(3V3) pins together. This approach requires only one 3.3 V power
supply for both pads, the CPU, and peripherals. While this solution is simple, it does not
support powering down the I/O pad ring “on the fly” while keeping the CPU and
peripherals alive.
The second option uses two power supplies; a 3.3 V supply for the I/O pads (VDD(3V3)) and
a dedicated 3.3 V supply for the CPU (VDD(REG)(3V3)). Having the on-chip voltage regulator
powered independently from the I/O pad ring enables shutting down of the I/O pad power
supply “on the fly” while the CPU and peripherals stay active.
The VBAT pin supplies power only to the RTC domain. The RTC operates at very low
power, which can be supplied by an external battery. The device core power
(VDD(REG)(3V3)) is used to operate the RTC whenever VDD(REG)(3V3) is present. There is no
power drain from the RTC battery when VDD(REG)(3V3) is at nominal levels and
VDD(REG)(3V3) > VBAT.
VDD(3V3)
VSS
VDD(REG)(3V3)
(typical 3.3 V)
LPC178x/7x
to I/O pads
REGULATOR
MAIN POWER DOMAIN
to core
to memories,
peripherals,
oscillators,
PLLs
VBAT
(typical 3.0 V)
RTCX1
RTCX2
VDDA
VREFP
VSSA
POWER
SELECTOR
32 kHz
OSCILLATOR
ULTRA-LOW
POWER
REGULATOR
BACKUP REGISTERS
REAL-TIME CLOCK
RTC POWER DOMAIN
DAC
ADC
ADC POWER DOMAIN
Fig 8. Power distribution
002aaf530
LPC178X_7X
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 5.5 — 26 April 2016
© NXP Semiconductors N.V. 2016. All rights reserved.
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