L6585D
Pin settings
5/25
2.2
Functions
Table 1.
Pin functions
Pin num.
Name
Function
1OSC
An external capacitor to GND fixes the half-bridge switching frequency with a
±3% precision.
2RF
Voltage reference able to source up to 240A; the current sunk from this pin fixes
the switching frequency of the half-bridge for each operating state.
A resistor (RRUN) connected to ground sets the half-bridge operating frequency
combined with the capacitor connected to the pin OSC.
A resistor connected to EOI (RPRE) – in parallel with RRUN – sets the maximum
half-bridge switching frequency during pre-heating.
3EOI
Connected to ground by a capacitor that, combined with RPRE, determines the
ignition duration
Pre-heating: low impedance to set high switching frequency
Ignition and run mode: high impedance with controlled current sink in case of
HBCS threshold triggering.
4Tch
Pin for setting the pre-heating time and the protection intervention.
Connect a RC parallel network (RD and CD) to ground
Pre-heating: the CD is charged by an internal current generator. When the pin
voltage reaches 4.63V the generator is disabled and the capacitor discharges
because of RD; once the voltage drops below 1.52V, the preheating finishes, the
ignition phase starts and the RDCD is discharged to ground.
Run mode: according to the kind of fault (either over-current or EOL) the
internal generator charges the RC parallel network and appropriate actions are
taken to stop the application. During proper behavior of the IC, this pin is low
impedance.
5EOLP
Pin to program the EOL comparator.
It is possible to select both the EOL sensing method and the window comparator
amplitude by connecting a resistor (REOLP) to ground.
6EOL-R
Input for the window comparator and re-lamp function.
It can be used to detect the lamp ageing for either “l(fā)amp to ground” and “block
capacitor to ground” configurations.
According to the EOLP pin setting, it is possible to program:
– the window amplitude (VW)
– the center of the window (VSET) either fixed or in tracking with the PFC output
bus.
This function is blanked during the ignition phase.
In case of either lamp disconnection or removal, a second threshold (VSL-UP)
crossing latches the IC and drives the chip in “ready-mode” so that when the
voltage at EOL-R pin is brought below VSL-DOWN (re-lamp) a new pre-
heating/ignition sequence is repeated.
7CTR
Input pin for:
– PFC over-voltage detection: the PFC driver is stopped until the voltage returns
in the proper operating range
– Feedback disconnection detection
– reference for End-of-life in case tracking reference;
– shut-down: forcing the pin to a voltage lower than 0.75V, the IC shuts down in
unlatched condition.
8MULT
Main input to the multiplier. This pin is connected to the rectified mains voltage
via a resistor divider and provides the sinusoidal reference to the PFC current
loop.