TLD2326EL_15 Datasheet, PDF (17/30 Pages) Infineon Technologies AG – 3 Channel High Side Current Source

TLD2326EL
7
IN_SETx Pin
The IN_SET pin is a multiple function pin for output current definition, input and diagnostics:
IN_SETx Pin
Logic
IN_SET
IIN_SET
VIN_SET
VIN_SET(OL /SC)
GND
Figure 8 Block Diagram IN_SET pin
7.1
Output Current Adjustment via RSET
The output current of each channel can be adjusted independently. The current adjustment can be done by placing
a low power resistor (R_SET) at the IN_SETx pin to ground. The dimensioning of the resistor can be done using the
formula below:
R_SET
=
-----^k------
I_OUT
(4)
The gain factor k (R_SET * output current) is specified in Pos. 9.2.4 and Pos. 9.2.5. The current through the R_SET is
defined by the resistor itself and the reference voltage V_{IN_SET(ref)}, which is applied to the IN_SET during supplied
device.
7.2
Smart Input Pin
The IN_SETx pin can be connected via R_SET to the open-drain output of a µC or to an external NMOS transistor
as described in Figure 9. This signal can be used to turn off the output stages of the IC. A minimum IN_SET
current of I_{IN_SET(act)} is required to turn on the output stages. This feature is implemented to prevent glimming of
LEDs caused by leakage currents on the IN_SET pin, see Figure 11 for details. In addition, the IN_SET pin offers
the diagnostic feedback information. In case of a fault event the IN_SET voltage is increased to V_{IN_SET(OL/SC)}
Pos. 8.4.2. Therefore, the device has two voltage domains at the IN_SET-pin, which is shown in Figure 12.
Note: If one output has a present fault (open load or short circuit) and one or both of the other channels are dimmed
via PWM at the IN_SET-pins a short spike to V_{IN_SET(OL/SC)} is possible. Please refer to Chapter 8.3.
Data Sheet
17
Rev. 1.1, 2015-03-24