lpc1759 NXP Semiconductors, lpc1759 Datasheet - Page 62

• Manufacturer Part Number: lpc1759
• Description: Lpc17xx Device Highlight
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC1759_58_56_54_52_51_4
Product data sheet
Fig 30. LPC1759/58/56/54/52/51 USB device port configuration
14.2 Crystal oscillator XTAL input and component selection
LPC17xx
The input voltage to the on-chip oscillators is limited to 1.8 V. If the oscillator is driven by a
clock in slave mode, it is recommended that the input be coupled through a capacitor with
C
capacitor to ground C
mode, a minimum of 200 mV(RMS) is needed.
In slave mode the input clock signal should be coupled by means of a capacitor of 100 pF
(Figure
corresponds to a square wave signal with a signal swing of between 280 mV and 1.4 V.
The XTALOUT pin in this configuration can be left unconnected.
External components and models used in oscillation mode are shown in
Table 19
and the capacitances C
fundamental mode oscillation (the fundamental frequency is represented by L, C
R
not be larger than 7 pF. Parameters F
manufacturer.
Fig 31. Slave mode operation of the on-chip oscillator
i
S
= 100 pF. To limit the input voltage to the specified range, choose an additional
). Capacitance C
USB_UP_LED
USB_CONNECT
USB_D+
USB_D−
V
BUS
31), with an amplitude between 200 mV(RMS) and 1000 mV(RMS). This
and
Table
All information provided in this document is subject to legal disclaimers.
33 Ω
33 Ω
P
20. Since the feedback resistance is integrated on chip, only a crystal
in
g
Rev. 04.02 — 1 April 2010
V
which attenuates the input voltage by a factor C
Figure 32
X1
DD
and C
V
DD
X2
represents the parallel package capacitance and should
need to be connected externally in case of
OSC
XTAL1
LPC1759/58/56/54/52/51
LPC1xxx
C i
100 pF
, C
L
, R
S
002aae835
32-bit ARM Cortex-M3 microcontroller
C g
and C
P
are supplied by the crystal
V
SS
V
BUS
D+
D−
USB-B
connector
002aad943
i
/(C
© NXP B.V. 2010. All rights reserved.
Figure 32
i
+ C
g
). In slave
L
and
and in
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