Datasheet
LPC540xx All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2018. All rights reserved.
Product data sheet Rev. 1.8 — 22 June 2018 147 of 168
NXP Semiconductors
LPC540xx
32-bit ARM Cortex-M4 microcontroller
(1) See Section 13.6 “XTAL oscillator” for the values of C1, C2, C3, and C4.
(2) Position the decoupling capacitors of 0.1 μF and 0.01 μF as close as possible to the V
DD
pin. Add one set of decoupling
capacitors to each V
DD
pin.
(3) Position the decoupling capacitors of 0.1 μF as close as possible to the VREFN and V
DDA
pins. The 10 μF bypass capacitor
filters the power line. Tie V
DDA
and VREFP to V
DD
if the ADC is not used. Tie VREFN to V
SS
if ADC is not used.
(4) Uses the ARM 10-pin interface for SWD.
(5) When measuring signals of low frequency, use a low-pass filter to remove noise and to improve ADC performance. Also see
Ref. 3
.
(6) External pull-up resistors on SWDIO and SWCLK pins are optional because these pins have an internal pull-up enabled by
default on initial device revision 0A (Boot ROM version 21.0). For future device revision 1B (Boot ROM version 21.1), these pins
are in high Z mode (internal pull-up and pull-down disabled). See the Errata sheet LPC540xx (IOCON.1) for more details. For
future device revision 1B (Boot ROM version 21.1), GPIO pins SWDIO/PIO0_12, SWCLK/PIO0_11, PIO0_2, PIO0_3, PIO0_4,
PIO0_5, and PIO0_6 have the input buffer enabled (DIGIMODE, bit 8 is enabled in IOCON register) and will be floating by
default. If unused, it is recommended to externally terminate this pins to prevent leakage.
(7) Position the decoupling capacitor of 0.1 F as close as possible to the V
BAT
pin. Tie V
BAT
to V
DD
if not used.
Fig 46. Power, clock, and debug connections
SWDIO/PIO0_12
SWCLK/PIO0_11
RESETN
V
SS
V
SSA
PIO0_5
ADCx
RTCXIN
RTCXOUT
V
DD
V
DDA
VREFP
VREFN
LPC
3.3 V
3.3 V
(1)
(2)
(3)
(3)
(7)
(1)
DGND
DGND
AGND
1
3
5
7
9
2
4
6
8
10
DGND
DGND
DGND
C3
C4
0.01 μF
0.1 μF
DGND
10 μF
0.1 μF
AGND
AGND
AGND
10 μF
0.1 μF
0.1 μF
ISP select pins
n.c.
n.c.
n.c.
SWD connector
(6)
(4)
(6)
aaa-029082
PIO0_4
PIO0_6
3.3 V
~10 kΩ - 100 kΩ
VBAT
DGND
3.3 V
3.3 V
3.3 V
0.1 μF
XTALIN
XTALOUT
DGND
C1
C2
(5)
~10 kΩ - 100 kΩ
3.3 V