Integration Manual

Table Of Contents
TOBY-L3 series - System Integration Manual
TSD-19090601 - R13 System Integration Manual Page 107 of 143
u-blox GNSS
3.0 V device
24
GPIO3
1V8
B A
GND
U3
VCCB
VCCA
Unidirectional
Voltage Translator
C4
C5
3V0
TxD1
R1
INOUT
GNSS LDO
Regulator
SHDNn
R2
VMAIN
3V0
U1
22
GPIO2
55
SDA
54
SCL
R4 R5
1V8
SDA_A
SDA_B
GND
U2
SCL_A
SCL_B
VCCA
VCCB
I2C-bus Bidirectional
Voltage Translator
5
V_INT
C1
C2 C3
R3
SDA2
SCL2
VCC
DIR
OEn
OE
GNSS data ready
GNSS supply enabled
GND
TOBY-L3 series
Figure 53: Application circuit for connecting TOBY-L3 series modules to u-blox 3.0 V GNSS devices
Reference
Description
Part Number - Manufacturer
R1, R2, R4, R5
4.7 k Resistor 0402 5% 0.1 W
RC0402JR-074K7L - Yageo Phycomp
R3
47 k Resistor 0402 5% 0.1 W
RC0402JR-0747KL - Yageo Phycomp
C2, C3, C4, C5
100 nF Capacitor Ceramic X5R 0402 10% 10V
GRM155R71C104KA01 - Murata
U1, C1
Voltage Regulator for GNSS device and capacitor
See GNSS device Hardware Integration Manual
U2
I2C-bus Bidirectional Voltage Translator
TCA9406DCUR - Texas Instruments
U3
Generic Unidirectional Voltage Translator
SN74LVC1T45 - Texas Instruments
Table 41: Components for connecting TOBY-L3 series modules to u-blox 3.0 V GNSS devices
2.6.4.2 Guidelines for DDC (I2C) layout design
The DDC (I
2
C) interface requires the same considerations regarding electro-magnetic interference as any
other digital interface. Keep the traces short and avoid coupling with RF line or sensitive analog inputs,
since the signals can cause the radiation of some harmonics of the digital data frequency.