MAX-7 / NEO-7 / LEA-7 - Hardware Integration Manual
GPS.G7-HW-11006-1
Design
Page 21 of 55
Function
PIN
No
I/O Description
Remarks
UART
TxD
3
O
Serial Port
Communication interface can be programmed as TX-ready for DDC
interface. Leave open if not used.
RxD
4
I
Serial Port
Serial port input with internal pull-up resistor to VCC. Leave open if
not used. Do not use external pull up resistor.
USB
USB_DM
25
I/O
USB I/O line
USB2.0 bidirectional communication pin. Leave open if unused.
Implementations see
section 2.6.2.
USB_DP
26
I/O
USB I/O line
System
RESET_N
10
I
Hardware Reset
(Active Low)
Leave open if not used. Do not drive high.
TIMEPULSE
28
O
Timepulse
Signal
Configurable Timepulse signal (one pulse per second by default).
Leave open if not used.
EXTINT
27
I
Ext. Interrupt
Ext. Interrupt Pin. Int. pull-up resistor to
VCC
. Leave open if unused.
SDA
1
I/O
DDC Pins
DDC Data. Leave open if not used.
SCL
2
I
DDC Pins
DDC Clock. Leave open if not used.
Reserved
5, 9, 12,
21, 22, 23
-
Reserved
Leave open
Table 6: Pinout LEA-7N
3.3
Layout
This section provides important information for designing a robust GPS/GNSS system.
GPS/GNSS signals at the surface of the Earth are about 15 dB below the thermal noise floor. Signal loss from the
antenna to RF_IN pin of the module must be minimized as much as possible. When defining a GPS/GNSS
receiver layout, the placement of the antenna with respect to the receiver, as well as grounding, shielding and
jamming from other digital devices, are crucial issues requiring careful consideration.
3.3.1
Footprint and paste mask
Figure 8 through Figure 13 describe the footprint and provide recommendations for the paste mask for u-blox 7
LCC modules. These are recommendations only and not specifications. Note that the Copper and Solder masks
have the same size and position.
To improve the wetting of the half vias, reduce the amount of solder paste under the module and increase the
volume outside of the module by defining the dimensions of the paste mask to form a T-shape (or equivalent)
extending beyond the Copper mask. For the stencil thickness,
see section 5.2.1.
17.0 mm [669 mil]
22.
4 m
m
[881
.9 m
il]
1.0 mm
[39 mil]
0.
8 mm
[3
1.
5 m
il]
2.
45 m
m
[9
6.
5 m
il]
1.
1 mm
[43 m
il]
3.
0 mm
[11
8 m
il]
2.
15 m
m
[84
.5 m
il]
0.8 mm
[31.5 mil]
Figure 8: LEA-7 footprint
Stencil: 200
µ
m
15.7 mm [618 mil]
17.0 mm [669 mil]
20.8 mm [819 mil]
0.
8 mm
[31.
5
mi
l]
0.
6 mm
[23.
5
mi
l]
Figure 9: LEA-7 paste mask
