MAX-8 / MAX-M8 - Hardware Integration Manual
UBX-15030059 - R05
Hardware description
Page 5 of 31
Production Information
1
Hardware description
1.1
Overview
u-blox MAX-8 / MAX-M8 modules are standard precision GNSS positioning modules featuring the high
performance u-blox 8 / M8 positioning engine. Available in the industry standard MAX form factor in
a leadless chip carrier (LCC) package, they are easy to integrate and combine exceptional positioning
performance with highly flexible power, design, and connectivity options. SMT pads allow fully
automated assembly with standard pick & place and reflow-soldering equipment for cost-efficient,
high-volume production enabling short time-to-market.
☞
For product features see the
MAX-8 Data Sheet [1] and MAX-M8 Data Sheet [2].
☞
To determine which u-blox product best meets your needs, see the product selector tables on the
u-blox website
www.u-blox.com
.
1.2
Configuration
The configuration settings can be modified using UBX protocol configuration messages; see the
u-
blox 8 / u-blox M8 Receiver Description Including Protocol Specification [3]. The modified settings
remain effective until power-down or reset. If these settings have been stored in BBR (Battery Backed
RAM), then the modified configuration will be retained, as long as the backup battery supply (
V_BCKP
)
is not interrupted.
⚠
eFuse is One-Time-Programmable; it cannot be changed if it has been programmed once.
In order to save backup current, a u-blox
MAX-8C /
MAX-M8C
module configured in “single crystal“
mode can have the single-crystal feature turned off by means of a SW command. Hot start
performance will be degraded (no time information at startup).
Use the string in Table 1 to turn-off the single-crystal feature. This is recommended for low power
applications, especially if time will be delivered by GSM or uC.
eFuse
String
turn-off single-crystal feature
B5 62 06 41 09 00 01 01 92 81 E6 39 93 2B EE 30 31
Table 1: String to turn off single-crystal feature
1.3
Connecting power
u-blox MAX-8 / MAX-M8 positioning modules have up to three power supply pins:
VCC
,
VCC_IO
, and
V_BCKP
.
VCC: Main supply voltage
The
VCC
pin provides the main supply voltage. During operation, the current drawn by the module can
vary by some orders of magnitude, especially if enabling low-power operation modes. For this reason,
it is important that the supply circuitry be able to support the peak power for a short time (see the
MAX-8 Data Sheet [1] and MAX-M8 Data Sheet [2] for specification).
☞
When switching from backup mode to normal operation or at start-up, u-blox MAX-8 / MAX-M8
modules must charge the internal capacitors in the core domain. In certain situations, this can
result in a significant current draw. For low-power applications using Power Save and backup
modes, it is important that the power supply or low ESR capacitors at the module input can deliver
this current/charge.
☞
Use a proper GND concept. Do not use any resistors or coils in the power line.
