TS19340CS14

Taiwan Semiconductor

7

Version: B1705

APPLICATION INFORMATION (CONTINUE)

Pin Detail

Pin 5: PWM

The pin is for PWM dimming function control. The pin should be connected to internal 5V reference voltage when

using linear dimming function. Recommend operation frequency range from 100Hz to 10kHz.

The LED current vs. PWM duty ratio is shown as a formula following:

)

(

_

_

A

R

0.2

Ratio

Duty

PWM

I

S

LED(PWM)

×

=

Pin 6 : N/C

No connection.

Pin 7: GND

GND is the reference node of internal circuit.

Pin 8: COM

The COM pin is for PWM pulse filter. The PWM duty ratio will be converted to 3.2V (Duty=100%) ~ 0V (Duty=0%).

A suitable capacitor should be connected between the COM and ground.

Pin 9: SWO

The pin is an open drain output of the comparator for LED current cut-off function. The SWO pin will be pulled low

when the LED current is cut-off.

Pin 10: N/C

No connection.

Pin 11: PHO

The PHO pin is for transferring secondary-side voltage/current signal for the primary-side controller. It is an open

drain output of the two internal OP-AMPs for an external photo coupler. A capacitor and a resistor in series should

be connected between PHO and FB for constant voltage control, and a capacitor and a resistor in series should be

Pin 12: VSEN

PWM/CCH/CCL setting. The illustration is shown in Figure 5 and Figure 6.

The maximum LED Current is in the formula as follows:

)

( A

R

0.2

I

S

LED(max)

=

Pin 13: FB

The FB pin is for LED constant voltage control. The FB reference voltage will be 2.53V when the LED current is not

cut-off, and it will be 1.21V when the LED current is cut-off