User's Manual

Performing Advanced Functions
DINn
DINn
Stage 1 Stage 2
GND
Vcc
J3|4|5|6=3−4
"With Pull UP"
J3|4|5|6=1−2
"With Pull Down"
LPF
fg~50Hz
Stage 3
Mode=Static|Counter/Freq.
to u
C
"H"
from TIMEBA
SE
Mode=Counter|Freq.
GATE
16Bit Counter
LPF=ON/OFF
to uC
Fig. 15: Digital inputs
3.1.6 Digital Outputs
The Digital Outputs of the A740 are protected low-side switches (4 channels). An
optional pull-up-resistor can be connected to V
Extps
or V
batt
. The resistance value is
1KOhm.
When J2 is in position 3-4 and operating with external power supply (12-24V) one
output can source a maximum of 12mA (at 12V) to 24mA (at 24V) according to the
external power supply voltage. In this configuration a small LED or
OPTOCOUPLER can be attached directly to the output of the A740.
When J2 is in position 2-4 a maximum of 5.5mA (at 5.5V) to 7.5mA (at 7.5V) can
be sourced, depending on the battery voltage. Keep in mind that the current comes
from the battery!
In the configuration without a pull-up (J2 is in position 1-2) the load must be
connected to a voltage <= 30V.
Do not sink more than 30mA continuous current!
24