STMicroelectronics Demonstration board using a dual full-bridge L6227Q EVAL6227QR EVAL6227QR Fiche De Données

10/27

  

The L6227Q integrates two independent power MOS Full Bridges. Each power MOS has an 
R

DS(on)

 = 0.73 

Ω (typical value @ 25 °C), with intrinsic fast freewheeling diode. Cross 

conduction protection is achieved using a dead time (td = 1 

µs typical) between the switch 

off and switch on of two power MOS in one leg of a bridge.

Using N-channel power MOS for the upper transistors in the bridge requires a gate drive 
voltage above the power supply voltage. The bootstrapped (VBOOT) supply is obtained 
through an internal oscillator and few external components to realize a charge pump circuit 
as shown in 

. The oscillator output (VCP) is a square wave at 600 kHz (typical) with 

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

C

BOOT

220 nF

C

P

10 nF

D1

1N4148

D2

1N4148

D2

C

BOOT

D1

C

P

V

S

VS

A

VCP

VBOOT

VS

B

D01IN1328