LPC1763 datasheet(68/86 Pages) PHILIPS

68 / 86 page

LPC1769_68_67_66_65_64_63

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Product data sheet

Rev. 9.3 — 8 January 2014

68 of 86

NXP Semiconductors

LPC1769/68/67/66/65/64/63

32-bit ARM Cortex-M3 microcontroller

15. Application information

15.1 Suggested USB interface solutions

Remark: The USB controller is available as a device/Host/OTG controller on parts

LPC1769/68/66/65 and as device-only controller on part LPC1764.

If the LPC1769/68/67/66/65/64/63 VDD is always greater than 0 V while VBUS = 5 V, the

VBUS pin can be connected directly to the VBUS pin on the USB connector.

This applies to bus powered devices where the USB cable supplies the system power. For

systems where VDD can be 0 V and VBUS is directly applied to the VBUS pin, precautions

must be taken to reduce the voltage to below 3.6 V.

The maximum allowable voltage on the VBUS pin is 3.6 V. One method is to use a voltage

divider to connect the VBUS pin to the VBUS on the USB connector.

The voltage divider ratio should be such that the VBUS pin will be greater than 0.7VDD to

indicate a logic HIGH while below the 3.6 V allowable maximum voltage.

Use the following operating conditions:

VBUSmax = 5.25 V

VDD = 3.6 V

The voltage divider would need to provide a reduction of 3.6 V/5.25 V or ~0.686 V.

Fig 28. USB interface on a bus-powered device

LPC17xx

VDD(3V3)

1.5 k

USB_UP_LED

002aad940

USB-B

connector

USB_D+

USB_D

−

VBUS

VSS

RS = 33 Ω

LPC1763 Datasheet(PDF) 68 Page - NXP Semiconductors