SSL4120 datasheet(20/48 Pages) NXP

20 / 48 page

SSL4120

All information provided in this document is subject to legal disclaimers.

Product data sheet

Rev. 2 — 1 November 2012

20 of 48

NXP Semiconductors

SSL4120

Resonant power supply controller IC with PFC for LED lighting

7.7.9 PFC boost overvoltage protection, OVP boost (SNSBOOST pin)

An overvoltage protection circuit has been built in to prevent boost overvoltage during load

steps and mains transients. Switching of the power factor correction circuit is inhibited

when the voltage on the SNSBOOST pin > Vovp(SNSBOOST).

PFC switching resumes when VSNSBOOST <Vovp(SNSBOOST) again.

Overvoltage protection is also triggered when an open circuit occurs at the resistor

connected between the SNSBOOST pin and ground.

7.7.10 PFC short circuit/open-loop protection, SCP/OLP-PFC (SNSBOOST pin)

The PFC circuit does not start switching until the voltage on the SNSBOOST

pin > Vscp(SNSBOOST). This acts as short-circuit protection for the Vboost (SCP boost).

The SNSBOOST pin draws a small input current Iprot(SNSBOOST). If this pin gets

disconnected, the residual current pulls down VSNSBOOST which triggers the short-circuit

protection (SCP boost). This combination creates an open-loop protection (OLP-PFC).

7.8 HBC controller

The HBC controller converts the Vboost 400 V from the PFC into one or more regulated DC

output voltages and drives two external MOSFETs in a half-bridge configuration

connected to a transformer. The transformer forms the resonant circuit in combination with

the resonant capacitor and the load at the output. The transformer has a leakage

inductance and a magnetizing inductance. The regulation is realized using frequency

control.

7.8.1 HBC high-side and low-side driver (GATEHS and GATELS pins)

Both drivers have an identical driving capability. The output of each driver is connected to

the equivalent gate of an external high-voltage power MOSFET.

The low-side driver is referenced to the PGND pin and is supplied from the SUPREG pin.

The high-side driver is floating. The reference for the high-side driver is the HB pin,

connected to the midpoint of the external half-bridge. The high-side driver is supplied from

the SUPHS pin which is connected to the external bootstrap capacitor CSUPHS. When the

low-side MOSFET is on, the bootstrap capacitor is charged from the SUPREG pin using

the external diode DSUPHS.

7.8.2 HBC boost undervoltage protection, UVP boost (SNSBOOST pin)

The SNSBOOST pin voltage is sensed continuously to prevent the HBC controller trying

to operate at very low boost input voltages. When VSNSBOOST <Vuvp(SNSBOOST) HBC

switching stops the next time the GATELS pin goes HIGH. HBC switching resumes when

VSNSBOOST >Vstart(SNSBOOST).

SSL4120 датащи(PDF) 20 Page - NXP Semiconductors

SSL4120 датащи(HTML) 20 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48

датащи скачать

ссылки URL