TLD1313EL

EN Pin

Data Sheet

11

Rev. 1.0, 2013-08-08

5.2

Internal Supply Pin

The EN pin can be used to supply the internal logic. There are two typical application conditions, where this feature

can be used:

1) In “DC/DC control Buck” configurations, where the voltage

V

2) In configurations, where a PWM signal is applied at the Vbatt pin of a light module. The buffer capacitor

C

used to supply the Basic LED Driver IC during Vbatt low (

V

the turn-on time to the values specified in Pos. 9.2.13. Otherwise, the power-on reset delay time

t

POR (Pos. 5.4.7)

has to be considered.

The capacitor can be calculated using the following formula:

(1)

See also a typical application drawing in Chapter 10.

Figure 5

External circuit when applying a fast PWM signal on

V

BATT

()

()

–

()

–

---------------------------------------------------

⋅

=

GND

Output

control

OUT2

Internal

supply

Thermal

protection

Current

adjust

Basic LED Driver

GND

EN

VS

IN_SET

OUT3

OUT1