User's Manual Part 1

MC75 Hardware Interface Description

Strictly confidential / Draft

MC75_V00.190a Page 29 of 91 15.02.2005

VEXT

See note 1

TXD0/TXD1/RTS0/RTS1/DTR0 (driven by the application)

Serial interfaces

ASC0 and ASC1

Undefined

Active

PWR_IND

CTS0/CTS1/DSR0/DTR0

Figure 7: Signal states during turn-off procedure

Note 1: Depending on capacitance load from host application

3.2.2.2 Leakage Current in Power Down Mode

The leakage current in Power Down mode varies depending on the following conditions:

• If the supply voltage at BATT+ was disconnected and then applied again without starting

up the MC75 module, the leakage current ranges between 90µA and 100µA.

• If the MC75 module is started and afterwards powered down with AT^SMSO, then the

leakage current is only 50µA.

Therefore, in order to minimize the leakage current take care to start up the module at least

once before it is powered down.