Specifications

TC35 / TC37 Hardware Interface Description
TC35_37_HD_02_V03.10 - Released Page 47 of 92 21.12.2001
3.8 Control signals
The following control signals are available (2.65V CMOS level).
3.8.1 Inputs
Table 14: Input control signals of the TC35/TC37 module
Signal Pin Pin status Function Remarks
falling edge Power up GSM engine
Ignition
/IGT
left open or HiZ No operation
Active low ≥ 100ms (open
drain/collector driver required
in cellular device application)
Note: In a battery operated
TC35 or TC37 application, the
duration of the /IGT signal
must be 1s minimum when
the charger is connected and
you may want to go from
charging to Normal mode.
Power Down
/PD 0 Power down GSM engine
left open or HiZ No operation
Active low ≥ 3.5s (Open
drain/collector driver required
in cellular device application).
At the /PD signal the
watchdog signal of the GSM
engine can be traced (see
description in Table 18).
(HiZ = high impedance)