MAX-8 / MAX-M8 - Hardware Integration Manual 
UBX-15030059 - R05  Migration to u-blox 8 / M8 modules  Page 18 of 31 
Production Information     
3  Migration to u-blox 8 / M8 modules 
3.1  Migrating u-blox 7 designs to a u-blox 8 / M8 modules 
u-blox is committed to ensuring that products in the same form factor are backwards compatible over 
several technology generations. Utmost care has been taken to ensure there is no negative impact on 
function or performance and to make u-blox 8 / M8 modules as fully compatible as possible with u-
blox 7 versions. If using BeiDou, check the bandwidth of the external RF components and the antenna. 
For power consumption information, see the 
MAX-8 Data Sheet 
[1]
 
and 
MAX-M8 Data Sheet 
[2]. 
It is highly advisable that customers consider a design review with the u-blox support team to ensure 
the compatibility of key functionalities. 
☞  Selected pin names have been updated to agree with a common naming convention across u-blox 
modules.  The pins have not changed their operation and are the same physical hardware but with 
updated names.  
3.2  Hardware migration from MAX-6 to MAX-8 / M8  
Pin   MAX-6    MAX-8/M8     Remarks for Migration 
Pin Name  Typical Assignment  Pin Name  Typical Assignment 
1  GND  GND  GND  GND  No difference 
2  TxD  Serial Port  TXD  Serial Port  No difference 
3  RxD  Serial Port  RXD  Serial Port  No difference 
4  TIMEPULSE  Timepulse (1PPS)  TIMEPULSE  Timepulse (1PPS)  No difference 
5  EXTINT0  External Interrupt Pin  EXTINT  External Interrupt Pin  No difference 
6  V_BCKP  Backup Supply 
Voltage 
V_BCKP  Backup Supply Voltage  If this was connected to GND on u-
blox 6 module, OK to do the same in 
u-blox 8 / M8 . 
(MAX-8C / M8C: Higher backup 
current, see  
 Single Crystal) 
7  VCC_IO  IO supply voltage 
Input must always be 
supplied. Usually 
connect to VCC Pin 8 
VCC_IO  IO supply voltage Input 
must always be supplied. 
Usually connect to VCC 
Pin 8 
No difference 
8  VCC  Module power supply  
MAX-6G 1.75 – 2.0V 
MAX-6Q/C: 2.7 – 3.6V 
VCC  Module power supply  
MAX-8C/M8C: 1.65 – 3.6V 
MAX-8Q/M8Q: 2.7 – 3.6V 
the RESET function shall be used, a 
3k3 resistor from pin 9 to pin 8 in 
conjunction with an open drain buffer 
is required for u-blox 6. For MAX-8 / 
M8  modules pin 8 can be connected 
to pin 9 or can be left open. Do not 
populate the 3k3 resistor. 
Behavior of RESET
u-blox 7 / 8 / M8, a RESET erases the 
time information in the BBR, which 
was maintained in u-blox 6. There-
fore, in u-blox 7 / 8 / M8  a RESET will 
not result in a hot start, etc. 
10  GND  GND  GND  GND  No difference