Rainbow Electronics ATR0622 - Manual (Page 19)

19
4891CS–GPS–01/06
ATR0622 [Preliminary]
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
ATR0622 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