Supply management

AN4355

12/25

DocID025240 Rev 2

3

Supply management

The L648x devices integrate two linear voltage regulators which can be used for the

generation of the supply voltages of the gate drivers and the control logic. This allows the

device to operate both using a single supply source (the motor supply) and using separated

supply sources for gate driving and logic parts.

The supply pins of the device are listed in Table 2.

generated through the integrated linear regulator the VSREG pin must be connected to

ESD protection diode is turned on and the device can be damaged.

The device can be protected from this event adding an external low drop diode between the

VSREG and VS pins, charge pump diodes should be low drop too.

In order to supply directly the gate driving circuitry the external supply voltage must be

connected to both the VCC and VSREG pins; this way the internal linear regulator is

disabled.

Table 2. Device supply pins

Pin

Voltage range (operative)

Description

VS

Motor supply voltage. It is used by the device only as a reference

voltage for internal circuitry.

VBOOT

High-side gate drivers supply voltage. It is generated through

a charge pump circuit. The charge pump is supplied by the VCC pin.

VSREG

to VCC (VCC directly supplied)

Input voltage of the VCC linear voltage regulator.

VCC

From 7.5 V to 15 V

Output voltage of the VCC linear voltage regulator and low-side gate

drivers supply voltage. It is also the supply voltage of the charge

VCCREG

VREG (VREG directly supplied)

Input voltage of the VREG linear voltage regulator.

VREG

3.3 V

Output voltage of the VREG linear voltage regulator and logic supply

voltage.

VDD

3.3 V or 5 V

Digital outputs supply voltage.