
MAX-M10M - Integration manual
Avoid high resistance on the V_BCKP line. During the switch to V_BCKP supply, a short
current adjustment peak may cause a high voltage drop at the pin.
If the hardware backup mode is not used, leave the V_BCKP pin open.
3.1.4 Supply design examples
The two voltage ranges for VCC and V_IO allow three combinations when designing the receiver
power supply. Depending on the chosen combination, there are certain requirements to be
considered. These are summarized in
.
Option
Nominal supply (V)
Design case / Requirements
V_IO
VCC
1
3.3
3.3
3.3 V design where VCC and V_IO are connected together. See
using the hardware backup mode, and
for designs without backup supply.
•
VIO_SEL pin left open.
•
Voltage at VCC_RF pin = VCC - 0.1 V.
2
1.8
1.8
1.8 V design with VCC and V_IO connected together. This design requires an
accurate supply. See
for designs using the hardware backup mode, and
for designs without backup supply.
•
VIO_SEL is grounded.
•
Note that the voltage output at VCC_RF = VCC - 0.1 V.
•
Note that the maximum supply tolerance is 1.8 V ± 2 %.
To enter hardware backup mode, set the receiver to software standby
mode with the UBX-RXM-PMREQ message before switching off V_IO and
VCC.
3
1.8
1.8 / 3.3 / 5.0
VCC and V_IO are supplied independently. V_IO is supplied with an accurate 1.8 V
supply. VCC can be either supplied with 1.8 V , 3.3 V or 5.0 V. See
designs using the hardware backup mode, and
supply.
•
VIO_SEL pin is grounded.
•
Note that the maximum supply tolerance is 1.8 V ± 2 %.
•
Voltage at VCC_RF pin = VCC - 0.1 V.
To enter hardware backup mode, switch off V_IO 100 ms before VCC.
Alternatively, the receiver can be set to software standby mode with the
UBX-RXM-PMREQ message before switching off V_IO and VCC.
Table 29: Voltage supply options
Figure 21: VCC and V_IO connected to the main supply, and external power supply at V_BCKP
UBX-22038241 - R01
3 Hardware integration
Page 63 of 90
C1-Public