Application information

SEA05L

8/12

Doc ID 18462 Rev 1

Figure 4.

Output voltage versus output current

2.2

Compensation

The voltage control transconductance operational amplifier can be fully compensated. Both

its output and negative input are directly accessible for external compensation components.

2.3

LD pin function

The device provides a unique feature that allows highly efficient driving of an LED pilot-lamp.

The main benefit of this new feature is to allow reducing the standby power consumption of

the SMPS with the LED pilot-lamp.

The LD pin is an open-drain output able to sink 5 mA (peak), driven by the internal oscillator

at 1 kHz (typ.) square waveform with 12.5% duty cycle (see Figure 6). The internal mosfet

Connecting the LED pilot-lamp, with a resistor in series in order to limit the LED current, to

pin LD (as shown in Figure 5) reduces the power consumption of the LED while keeping the

same driving peak current. The LED driving current modulation frequency of 1 kHz (typ.)

eliminates the visual perception of flickering.

Vout

Iout

V o ltage re gula tion

V c c of the de vice in dependent from outp ut vo ltage)

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AM04987v1