atr0630 ATMEL Corporation, atr0630 Datasheet - Page 21

• Manufacturer Part Number: atr0630
• Description: Antaris4 Single-chip Gps Receiver - Atmel Corporation
• Manufacturer: ATMEL Corporation

Figure 4-1.
4920B–GPS–06/06
Connecting Example: Separate Power Supplies for RF and Digital Part Using the Internal LDOs
2.3V to 3.6V
1.5V to 3.6V
The ATR0630 contains a built in low dropout voltage regulator LDO18. This regulator can be
used if the host system does not provide the core voltage VDD18 of 1.8V nominal. In such case,
LDO18 will provide a 1.8V supply voltage from any input voltage VDD between 2.3V and 3.6V.
The LDO_EN input can be used to shut down VDD18 if the system is in standby mode.
If the host system does supply a 1.8V core voltage directly, this voltage has to be connected to
the VDD18 supply pins of the Core. LDO_EN must be connected to GND. LDO_IN can be con-
nected to GND. LDO_OUT must not be connected.
A second built in low dropout voltage regulator LDOBAT provides the supply voltage for the RTC
and backup SRAM from any input voltage VBAT between 1.5V and 3.6V. The backup battery
delivers the supply current if LDOBAT_IN is not powered.
0V or 3V to 3.6V
2.7V to 3.3V
NSHDN
1 µF
(X7R)
1 µF
(X7R)
LDOBAT_IN
LDO_OUT
VDDUSB
LDO_EN
LDO_IN
VBAT18
VDD18
VDDIO
VCC1
VCC2
VDIG
VBAT
VBP
ldoin
ldoen
ldoout
ldobat_in
vbat
vbat18
variable I/O domain
ATR0630 [Preliminary]
backup memory
USB SM and
1.8V to 3.3V
transceiver
Core
RTC
RF
ATR0630 internal
LDOBAT
LDO18
VDD
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