The Theory Of The Reset Circuit - SimCom SIM548C HD V1.01 Hardware Design

SIM548C Hardware Design
Figure 35: Theory of the GPS RTC circuit

4.6 The theory of the RESET Circuit

There is a RESET IC in the module's GPS part. If the input of the reset IC is lower than 2.3V, the
"reset" pin will keep low; then the input voltage is higher than 2.3V, the RESET IC will output a
low level voltage for about 220mS as a reset signal. After that the reset output pin will be kept
high. So, if the user wants to reset the module's GPS part, the GPS_M-RST should be pulled
down longer than 10ms, and then pull it up. The theory of the RESET Circuit is shown in the
figure:
Figure 36: Theory of the RESET circuit
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SIM548C_HD_V1.01 09.05.2008