9.6.5

PFC UVP

If the PFC_FB pin is below a threshold set by the user the device enters the PFC UVP fault and it is shut down.

The system provides two different times of intervention configurable by NVM: adaptive and slow.

The slow intervention allows to shut off the system in case the UVP threshold is confirmed for at least 100 ms.

The adaptive one allows to shut off the device immediately in case also the mains AC line is sensed below the

brownout threshold for at least 1 half line cycle. On the contrary, the shut off will be delayed as if the intervention

is set to slow, until the UVP and the mains conditions remain.

9.6.6

PFC_FB disconnection

If the PFC_FB is stuck low the system enters the PFC_FB disconnection fault state (latched) and it is turned off if

the disconnection faults detection is enabled in NVM.

9.6.7

PFC_CS disconnection

If the PFC_CS pin is stuck low (or high) during the the PFC soft-start the system enters the PFC_CS

disconnection fault state (latched) and it is shut down if the disconnection faults detection is enabled in NVM.

In case the PFC_CS is stuck high during the operative mode the system enters the PFC_CS disconnection fault

state and it is turned off if the disconnection faults detection is enabled in NVM.

9.6.8

PFC_ZCD disconnection

If the PFC_ZCD pin is stuck low or high during the PFC soft-start, the system enters the PFC_ZCD disconnection

fault (latched) and it is turned off if the disconnection faults detection is enabled in NVM.

9.7

LLC control and fault management

9.7.1

LLC related resources

Table 6. Pin descriptions

Pin name

Description

Level

Function

LLC_CS

Low-side current sense

0 - 500 mV

5-bit OLP

700 mV

OCP2 fault

LLC_AUX LLC auxiliary winding voltage sense

0.9 V

External burst-mode

2.5 V

LLC output OVP

LLC_FB

LLC OPTO feedback sense, burst comparator and SHUTDOWN

comparator

ADC, 10 bits

Feedback sense

Programmable

Burst comparator

125 mV

Shutdown comparator

HVG

High-side gate driving

-

-

LVG

Low-side gate driving

-

-

9.7.2

LLC OC1 comparator

The LLC OC1 comparator implements the overload protection (OLP). It monitors the LLC_CS pin with respect to

a programmable threshold. If the LLC_CS pin goes every cycle over the OC1 threshold for a programmable time,

the IC shuts down and enters the OLP fault.

Both threshold and duration are programmable trough NVM parameters.

9.7.3

LLC OC2 comparator

The LLC OC2 comparator sets an HW limit for the current flowing into the LLC resonant tank: it triggers the OCP2

fault.

STNRG011

LLC control and fault management

DS12075 - Rev 4

page 18/31