Datasheet

Circuit description L6226Q
10/29 Doc ID 14335 Rev 5
4 Circuit description
4.1 Power stages and charge pump
The L6226Q 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 Figure 5. 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 Ta bl e 6 .
Figure 5. Charge pump circuit
Table 6. Charge pump external components values
Component Value
C
BOOT
220 nF
C
P
10 nF
D1 1N4148
D2 1N4148
9
6
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3
96
$
9&3 9%227 96
%
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