L6585D_07 STMICROELECTRONICS [STMicroelectronics], L6585D_07 Datasheet - Page 18

• Manufacturer Part Number: L6585D_07
• Description: Combo IC for PFC and ballast control
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

CTR
8
18/25
CTR
This is a multi-function pin, connected to a resistive divider to the PFC output bus:
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PFC over-voltage: in case of PFC output overshoot (e.g. at start-up) that causes a
threshold crossing, the PFC section stops switching until the pin voltage falls below
3.26V (typ.); this is helpful because the bandwidth of the PFC error amplifier is narrow
so the control loop is not fast enough to properly reacts
Feedback disconnection: The OVP function above described (together with the static
one embedded in the PFC error amplifier) is able to handle “normal” over-voltage
conditions, i.e. those resulting from an abrupt load/line change or occurring at start-up.
In case of over-voltage generated when the upper resistor of the feedback output
divider fails open, the control loop can no longer read the information on the output
voltage and will force the PFC pre-regulator to work at maximum ON time; if this occurs
(i.e. the pin INV falls below 1.2V, typ.) and the CTR detects an OVP, the gate drivers
activity is immediately stopped, the device enters low consumption and the condition is
latched as long as the IC supply voltage is above the UVLO threshold;
Reference for EOL in case of tracking reading.
Disable: by forcing the pin below 0.75V an immediate unlatched shut-down is activated;
it can be also used as re-lamp in fact after the pin voltage is above 0.8V a pre-
heating/ignition sequence is repeated.
L6585D