Bus Connector - Siemens ASIC SIM 1-2 Function Manual

Functional Description of the SIM 1-2
2.3.4

Bus Connector

Bus Current Consumption
Using the resistor R
mA
50 . In the range from 2 mA to 10 mA, the SIM 1-2 automatically operates in
the asymmetric modulation mode. This means that to transmit, the mean current
consumption is raised to 10
The set mean bus current must always be at least 1 mA higher than the current
transferred to the application over VREG and VE (including DC/DC).
R [MΩ] = 0.05 * I
RISOLL
Conditions for R
the capacitor C
pulse load by the application or the DC/DC converter.
Caution 1
To achieve the minimum bus current tolerance of 3 %, resistors with a tolerance of
≤ 0.1 % must be used. As an alternative, the bus current can be matched over
R (see also tolerance calculation in section 2.3.7, "Reference Circuit RIREF,
RISOLL
RVCCVE, RVREG, RISOLL").
Caution 2
Transistor T1 and its cooling surface must be designed according to the set bus
current consumption and the resulting dissipation loss.
18
, the mean current taken from the bus is set from 2
RISOLL
mA
and then lowered again to the set value.
[mA]
BUS
: 100 KΩ ≤ R
RISOLL
must be dimensioned in the permitted range according to the
VE
≤ 2.5 MΩ
RISOLL
mA
to
SIM 1-2
C79000-G8976-C215-01