MAX-7 / NEO-7 / LEA-7 - Hardware Integration Manual
GPS.G7-HW-11006-1 Hardware description
Page 12 of 55
Name Component Function Comments
U1 LDO Regulates VBUS (4.4 …5.25 V)
down to a voltage of 3.3 V.
Almost no current requirement (~1 mA) if the GPS/GNSS receiver is operated as
a USB self-powered device, but if bus-powered LDO (U1) must be able to
deliver the maximum current. For the peak supply current, see a low-cost
DC/DC converter such as LTC3410 from Linear Technology.
C23,
C24
Capacitors Required according to the specification of LDO U1
D2 Protection
Protect circuit from overvoltage
Use low capacitance ESD protection such as ST Microelectronics USBLC6-2.
R4, R5 Serial
termination
resistors
Establish a full-speed driver
impedance of 28…44 Ω
A value of 27 Ω is recommended.
R11 Resistor
1 kΩ is recommended for USB self-powered setup. For bus-powered setup,
R11 can be ignored.
Table 2: Summary of USB external components