ATR0621P_08 Datasheet, PDF (21/31 Pages) ATMEL Corporation – GPS Baseband GPS Baseband

ATR0621P
4. Power Supply
The baseband IC is supplied with four distinct supply voltages:
• VDD18, the nominal 1.8V supply voltage for the core, the RF-I/O pins, the memory interface
and the test pins and all GPIO-pins not mentioned in next item.
• VDDIO, the variable supply voltage within 1.8V to 3.6V for following GPIO-pins: P1, P2, P8,
P12, P14, P16, P17, P18, P19, P20, P21, P23, P24, P25, P26, P27 and P29. In input mode,
these pins are 5V input tolerant.
• VDD_USB, the power supply of the USB pins: USB_DM and USB_DP.
• VBAT18 to supply the backup domain: RTC, backup SRAM and the pins NSLEEP, NSHDN,
LDO_EN, VBAT18, P9/EXTIN0, P13/EXTINT1, P22/RXD2 and P31/RXD1 and the 32kHz
oscillator. In input mode, the four GPIO-pins are 5V input tolerant.
Figure 4-1, Figure 4-2 and Figure 4-3 show examples of the wiring of ATR0621 power supply.
Figure 4-1. External Wiring Example Using Internal LDOs and Backup Power Supply
2.3V to 3.6V
NSHDN
LDO_IN
LDO_EN
LDO_OUT
ldoin
ldoen
ldoout
ATR0621P internal
LDO18
1.5V to 3.6V
1 µF
(X7R)
VDD18
VDDIO
LDOBAT_IN
VBAT
1 µF
(X7R)
VBAT18
0V or 3V to 3.6V
VDDUSB
Core
1.8V to 3.3V
variable IO Domain
ldobat_in
vbat
vbat18
LDOBAT
vdd
RTC
Backup Memory
USB SM and
Transceiver
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4890H–GPS–08/08