19

4925G–GPS–06/08

ATR0625P

The USB Transceiver is disabled if VDD_USB < 2.0V. In this case the pins USB_DM and

USB_DP are connected to GND (internal pull-down resistors). The USB Transceiver is enabled

if VDD_USB within 3.0V and 3.6V.

Figure 4-3.

External Wiring Example Using Internal LDOs, USB Supply Voltage and Backup Power Supply

ATR0625P internal

USB-VSB 5V

VDDUSB

1.5V to 3.6V

1 µF

(X7R)

ldoout

ldoen

ldoin

LDO18

LDO_IN

1 µF

(X7R)

VDDIO

LDO_EN

NSHDN

VDD18

External

LDO 3.3V

LDO_OUT

USB SM and

Transceiver

1.8V to 3.3V

variable IO Domain

RTC

Backup Memory

Core

vbat18

vbat

vdd

ldobat_in

LDOBAT

LDOBAT_IN

VBAT

VBAT18