AN2640 datasheet(21/36 Pages) STMICROELECTRONICS

21 / 36 page

AN2640

L6382D5 - power management units for microcontrolled ballast

21/36

capacitor is supplied thanks to a patented structure that replaces an external diode

connected between this capacitor and VCC.

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Pin 12: HSG. The same as pin 9 but is able to drive the half-bridge high side Power

MOSFET gate.

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Pin 13: OUT. This pin is the high side floating ground and it is connected at the midpoint

of the half-bridge.

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Pin 14: not connected

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Pin 15: HVSU. This pin allows driver startup and two resistors of 10

Ω are connected at

the DC bus according to the Vref current requirement.

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Pin 16: not connected

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Pin 17: HEG (not used)

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Pin 18: CSO. This pin is the output of the current sense comparator. During normal

operation this pin is forced low, but if the voltage on the CSI pin exceeds 0.55 V this pin

is high with 5 V logic level.

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Pin 19: CSI. This is the input of the current sense comparator.The circuit that is

connected at this pin is shown in Figure 22. During the operating mode if overcurrent

occurs in the half-bridge, the voltage on the R28 resistor increases and when it

exceeds 0.55 V, the L6382 forces both half-bridge drivers low. This condition remains

until the input signals LGI and HGI are low simultaneously (dead time) or Vcc is below

the undervoltage lockout.

Figure 22.

Circuit connected at CSI pin

The capacitor C20 is used to filter the voltage on the CSI pin.

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Pin 20: Vref. This pin provides a precise voltage reference of 5 V with a current

capability up to 30 mA. This voltage is used to supply the ST7 microcontroller which

avoids adding external components. To ensure voltage stability and prevent noise, a

220 nF capacitor is recommended between this pin and GND.

AN2640 Datasheet(PDF) 21 Page - STMicroelectronics