Datasheet

LPC82x All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 1 — 1 October 2014 70 of 81
NXP Semiconductors
LPC82x
32-bit ARM Cortex-M0+ microcontroller
14.4 Termination of unused pins
Table 29 shows how to terminate pins that are not used in the application. In many cases,
unused pins may should be connected externally or configured correctly by software to
minimize the overall power consumption of the part.
(1) See Section 14.1 “XTAL input” for the values of C1 and C2.
(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
DD
pins. The 10 μF bypass capacitor
filters the power line. Tie 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. 4
.
Fig 42. Power, clock, and debug connections
SWDIO/PIO0_2
SWCLK/PIO0_3
RESET/PIO0_5
V
SS
V
SSA
PIO0_12
ADC_0
PIO0_8/XTALIN
PIO0_9/XTALOUT
V
DD
(2 to 5 pins)
VREFP
PIO0_6/ADC_1/VDDCMP
VREFN
LPC82x
3.3 V
3.3 V
DGND
DGND
DGND
DGND
AGND
1
3
5
7
9
2
4
6
8
10
Note 4
Note 5
Note 5 (ADC_1),
Note 3 (VDDCMP)
C1
C2
Note 1
DGND
DGND
Note 2
Note 3
0.01 μF
0.1 μF
3.3 V
AGND
AGND
AGND
10 μF
0.1 μF
0.1 μF
ISP select pin
n.c.
n.c.
n.c.
SWD connector
3.3 V
~10 kΩ - 100 kΩ
~10 kΩ - 100 kΩ
aaa-015073