AN993 Datasheet, PDF (7/27 Pages) STMicroelectronics – Electronic ballast with PFC using L6574 and L6561

AN993
L6574 ballast driver
Table 1. Description of device pins (continued)
Number
Name
Function
Enable 1. This pin (active high), forces the device into a latched shutdown state (like
in undervoltage conditions). There are two ways of resuming normal operation: the
8
EN1
first is by reducing the supply voltage below the undervoltage threshold and then
increasing it again until the valid supply is recognized; the second is by activating the
EN2 input (see Figure 9). The Enable 1 is specifically designed for strong faults (for
example, in case of lamp disconnection).
Enable 2. EN2 input (active high) restarts the start-up procedure (preheating and
9
EN2
ignition sequence). This feature is useful if the lamp does not turn on after the first
ignition sequence (see Figure 10).
10
GND Ground.
Low-side driver output. This pin must be connected to the low-side power MOSFET
11
LVG
gate of the half bridge. A resistor connected between this pin and the power
MOSFET gate can be used to reduce the peak current.
12
VS
Supply voltage. This pin is connected to the supply filter capacitor (15.6 V typical).
13
N.C.
Not connected. This pin sets a distance between the pins related to the high-voltage
side and those related to the low-voltage side.
14
OUT
High-side driver floating reference. This pin must be connected close to the source of
the high-side power MOSFET or IGBT.
High-side driver output. This pin must be connected to the high-side power MOSFET
15
HVG gate of the half bridge. A resistor connected between this pin and the power
MOSFET gate can be used to reduce the peak current.
Bootstrapped supply voltage. The bootstrap capacitor must be connected between
16
VBOOT
this pin and OUT. A patented integrated circuit replaces the external bootstrap diode
by means of a high-voltage DMOS, synchronously driven with the low-side power
MOSFET.
Doc ID 5656 Rev 10
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