Dual SIM connection
LZT 123 7676 R1A
5
other active low, which permit a single control signal to select either SIM1
or SIM2 without additional logic circuitry.
The pull-up resistor value of 82k
Ω
on SIMDAT1 and SIMDAT2 not only
achieves the idle state pull-up but also compensates for the insertion of
the analogue switch into the SIMDATA signal.
Note : Due to the relatively high resistance of the pull-up on SIM Data
signals, the capacitance of the SIM Data line must be kept as low as
possible. Typically SIM circuits will not pass Type-Approval testing if the
SIM Data signal has a capacitive load greater than a few picoFarads.
