SEA05L Datasheet, PDF (4/12 Pages) STMicroelectronics – Advanced constant voltage and constant current controller with very efficient LED pilot-lamp driver

Operation
SEA05L
Table 4. Pin functions (continued)
Pin number Name
Function
Inverting input of the voltage loop op-amp. The pin is typically used for the
3
Vctrl voltage control loop and is connected to the midpoint of a resistor divider
that senses the output voltage.
Open-drain output able to sink 5 mA (peak), driven by the internal oscillator
at 1 kHz square waveform with 12.5% duty cycle. The internal mosfet starts
4
LD
to switch when V_CC is above the turn-on threshold (typ. 3 V) and it is off (LD
high impedance) when V_CC is below the UVLO of the IC. The pin can be
connected to an external LED pilot-lamp with a resistor in series in order to
limit the LED current
Common open-drain output of the two internal op-amps. The pin, only able
5
OUT to sink current, is typically connected to the branch of the optocoupler's
photodiode to transmit the error signal to the primary side.
Supply voltage of the device. A small bypass capacitor (0.1 µF typ.) to GND,
6
V_CC located as close to the IC pins as possible, might be useful to get a clean
supply voltage.
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Doc ID 18462 Rev 1