GC864 Hardware User Guide
1vv0300874 Rev.1 – 2010-03-29
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved.
Page 40 of 64
TIP:
Note that the TC7SZ07AE has open drain output; therefore the resistor R2 is
mandatory.
NOTE:
The UART input line TXD (rx_uart) of the GC864-QUAD V2 / GC864-DUAL V2 is NOT
internally pulled up with a resistor, so there may be the need to place an external
47K
Ω
pull-up resistor, either the DTR (dtr_uart) and RTS (rts_uart) input lines are
not pulled up internally, so an external pull-up resistor of 47K
Ω
may be required.
Care must be taken to avoid latch-up on the GC864-QUAD V2 / GC864-DUAL V2 and
the use of this output line to power electronic devices shall be avoided, especially for
devices that generate spikes and noise such as switching level translators, micro
controllers, failure in any of these condition can severely compromise the GC864-
QUAD V2 / GC864-DUAL V2 functionality.
NOTE:
In case of reprogramming of the module has to be considered the use of the RESET
line to start correctly the activity.
The preferable configuration is having an external supply for the buffer level
translator.
