Datasheet
LPC1315_16_17_45_46_47 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 3 — 20 September 2012 61 of 77
NXP Semiconductors
LPC1315/16/17/45/46/47
32-bit ARM Cortex-M3 microcontroller
12. Application information
12.1 Suggested USB interface solutions
12.2 XTAL input
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
i
= 100 pF. To limit the input voltage to the specified range, choose an additional
capacitor to ground C
g
which attenuates the input voltage by a factor C
i
/(C
i
+ C
g
). In slave
mode, a minimum of 200 mV(RMS) is needed.
Fig 28. USB interface on a self-powered device
LPC1345/46/47
USB-B
connector
USB_DP
USB_CONNECT
soft-connect switch
USB_DM
USB_VBUS
V
SS
V
DD
R1
1.5 kΩ
R
S
= 33 Ω
002aag564
R
S
= 33 Ω
Fig 29. USB interface on a bus-powered device
LPC1345/46/47
V
DD
R1
1.5 kΩ
002aag565
USB-B
connector
USB_DP
USB_DM
USB_VBUS
V
SS
R
S
= 33 Ω
R
S
= 33 Ω