Neoway N75 - Usim

N75
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
25
⚫
USB_ID is used for the OTG function. Pull USB_ID to low level, and the module will work in host
mode. To use the OTG function, supply a voltage to USB_VBUS. See Figure 3-14.
⚫
Pull USB_ID low before supplying power for USB_VBUS.
PCB Design Guidelines
⚫
Place filer capacitors on the USB_VBUS line as close to the pin of the module as possible and
the ESD component as close to the USB connector as possible.
⚫
Place the ESD triodes on USB_DP and USB_DM lines as close to the USB connector as
possible.
⚫
USB_DM and USB_DP traces should be routed in differential mode, and the differential
impedance of the transmission line is 90Ω.
⚫
Isolate USB traces from traces of other signals by connecting their grounds to main ground.
3.3.3 USIM
Signal
Pin
I/O
Function
Remarks
USIM1_VCC
35
PO
USIM1 power output
Compatible with 1.8 V/2.85 V UIM card
USIM1_DATA
36
B
USIM data IO
A 10 kΩ resistor is required between
USIM1_VCC and USIM1_DATA.
USIM1_CLK
37
DO
USIM1 clock output
USIM1_RESET
38
DO
USIM1 reset
USIM1_DET
39
DI
USIM1 detect
A pull-up resistor is recommended
N75 provides one USIM1 interface by default. USIM2 interface is a multiplex function of Ethernet
interface and compatible with 1.8V/2.85V USIM card. For details, see Section 3.7 MUX Interfaces.
Figure 3-15 shows the reference design of the USIM card interface.