Sim Card - Neoway WM620-A Hardware User's Manual

WM620 Hardware User Guide

2.4 SIM Card

PIN Signal name
13 V_SIM
14 SIM_CLK
15 SIM_RST
16 SIM_DATA
WM620 module supports 3V & 1.8V SIM cards. The SIM_DATA pin needs an externally 10K pull-up
resistor connected to V_SIM.The SIM_CLK is the clock signal, normally 3.25MHz. Bifurcation is not
recommended at the PCB trace of SIM_CLK.
Include SIM_DATA and SIM_CLK, the traces should be as short as possible and surrounded by the ground
copper to reduce the RF interference. The total distributed capacitance, include the junction capacitance of the
ESD diode or other device, can't be higher than 120pF.
PIN1, VCC
The SIM card application circuit is shown in Figure 2-9. In
strong ESD, ESD diodes or ESD varistors are strongly
place closed to SIM card. In some clear applications, SIM card is installed in closed box without human touch,
22~33pF MLCC capacitors can replace the ESD diodes for cost down.
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I/O
PWR SIM ard power output
DO SIM card clock output
DO SIM card reset output
I/O SIM card data input/output
Figure 2-9a, SIM card and ESD devices
Figure 2-9b, the recommended
Figure 2-9c, a sample of SIM card socket
PIN2, RST PIN3, CLK
V1.1
Function description
ESD diode array
PIN4, GND PIN5, VPP
automotive electronics or other applications with
recommended, such as T1 to T4. T1 to T4 should be
Note
1.8/3.0V
1.8/3.0V
1.8/3.0V
1.8/3.0V
PIN6, DATA
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