AMY-5M - Hardware Integration Manual
GPS.G5-MS5-08207-A3
Preliminary
Design-in
Page 13 of 54
2.1.6
Single 1.75…2.0 V supply
The single 1.8V power supply a very efficient configuration to run u-blox 5 receivers (see section 2.1.3 for
details). Assure minimal serial resistance in the power supply as the current consumption during operation varies
significantly over time.
C
AMY-5
VDD_B
VDD_IO
1.65...3.6 V
XTAL_IN
XTAL_OUT
V_DCDC
1.75...2.0 V
Main Battery
1.4...3.6 V
Backup Battery
V_BCKP
VDD_ANA
VDD_LNA
VDD_C
V_TH
leave
V_TH
open
Crystal
C20
f
XTAL
= 32.768 kHz
Y2
C19
(optional)
VDD_3V
VDD_RF
When connecting to
V_DCDC a filter is imperative
1.8V
Connect
XTAL_IN
to GND
if no RTC used
V_RESET
Supply
Filter
Figure 5: Single 1.75…2.0 V supply (for supply filter see Figure 3).
2.1.6.1
RF supply voltage
With a single 1.8 V supply, VDD_3V must be shorted with the VDD_RF pin, so that the internal LDO is shorted
and there is no voltage drop. The other LDOs in the RF unit provide improved supply rejection at very low
dropout voltage and are always required.