L6230 Ver la hoja de datos (PDF) - STMicroelectronics

Número de pieza

componentes Descripción

Fabricante

L6230

DMOS driver for three-phase brushless DC motor

STMicroelectronics 

L6230

5

Circuit description

Circuit description

5.1

Power stages and charge pump

The L6230 integrates a three-phase bridge, which consists of 6 power MOSFETs connected

as shown on the block diagram (see Figure 1), each power MOS has an

RDS(ON) = 0.73 Ω (typical value @ 25 °C) with intrinsic fast freewheeling diode. Cross

conduction protection is implemented by using a dead time (tDT = 1 µs typical value) set by

internal timing circuit between the turn off and turn on of two power MOSFETs in one leg of

a bridge.

Pins VSA and VSB must be connected together to the supply voltage (VS).

Using N-channel power MOS for the upper transistors in the bridge requires a gate drive

voltage above the power supply voltage. The bootstrapped supply (VBOOT) is obtained

through an internal oscillator and few external components to realize a charge pump circuit

as shown in Figure 6. The oscillator output (pin VCP) is a square wave at 600 kHz (typically)

with 10 V amplitude. Recommended values/part numbers for the charge pump circuit are

shown in Table 7.

Table 7.

Charge pump external component values

Component

CBOOT

CP

D1

D2

Value

220 nF

10 nF

1N4148

1N4148

Figure 6. Charge pump circuit

VS

D1

D2

CBOOT

CP

VCP

VBOOT

VSA VSB

Doc ID 18094 Rev 2

11/24

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