TLD1125EL_15 Datasheet, PDF (13/36 Pages) Marl International Limited – Basic LED Driver

6
PWMI Pin
The PWMI pin is designed as a dual function pin.
TLD1125EL
PWMI Pin
PWMI
I_{PWMI (L)}
Output Control
VPWMI
Figure 7 Block Diagram PWMI pin
The pin can be used for PWM-dimming via a push-pull stage of a micro controller, which is connecting the PWMI-
pin to a low or high potential.
Note: The micro controller’s push-pull stage has to able to sink currents according to Pos. 6.3.18 to activate the
device.
Furthermore, the device offers also an internal PWM unit by connecting an external-RC network according to
Figure 10.
6.1
PWM Dimming
A PWM signal can be applied at the PWMI pin for LED brightness regulation. The dimming frequency can be
adjusted in a very wide range (e.g. 400 Hz). The PWMI pin is low active. Turn on/off thresholds V_PWMI(L) and
V_PWMI(H) are specified in parameters Pos. 6.3.15 and Pos. 6.3.16.
V_PWMI
I_OUT
t_{ON (PWMI )}
t_{OFF(PWMI )}
t
100%
80%
20%
t
Figure 8 Turn on and Turn off time for PWMI pin usage
Data Sheet
13
Rev. 1.0, 2013-08-08