L6388ED STMicroelectronics, L6388ED Datasheet - Page 6

• Manufacturer Part Number: L6388ED
• Description: IC DRIVER HI/LO SIDE HV 8-SOIC
• Manufacturer: STMicroelectronics
• Type: High Side/Low Sider

Specifications of L6388ED

• Configuration: High and Low Side, Synchronous
• Input Type: Non-Inverting
• Delay Time: 225ns
• Current - Peak: 400mA
• Number Of Configurations: 1
• Number Of Outputs: 2
• High Side Voltage - Max (bootstrap): 600V
• Voltage - Supply: 17V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Product: Half-Bridge Drivers
• Rise Time: 100 ns
• Fall Time: 80 ns
• Maximum Power Dissipation: 750 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Bridge Type: Half Bridge
• Minimum Operating Temperature: - 45 C
• Number Of Drivers: 2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

L6388
has to be long enough to charge the capacitor.
The bootstrap driver introduces a voltage drop due to the DMOS RDSON (typical value: 125 Ohm). At low fre-
quency this drop can be neglected. Anyway increasing the frequency it must be taken in to account.
The following equation is useful to compute the drop on the bootstrap DMOS:
where Q
and T
For example: using a power MOS with a total gate charge of 30nC the drop on the bootstrap DMOS is about
1V, if the T
V
circuit topology doesn't allow a sufficient charging time, an external diode can be used.
Figure 8. Bootstrap Driver.
6/11
drop
charge
has to be taken into account when the voltage drop on C
gate
charge
is the charging time of the bootstrap capacitor.
is the gate charge of the external power MOS, R
is 5µs. In fact:
V
V
S
S
V
drop
D
=
BOOT
I
V
ch
drop
arg
a
b
e
R
=
HVG
HVG
LVG
LVG
dson
30nC
-------------- - 125Ω
5µs
→
⋅
V
drop
dson
BOOT
=
∼
V
V
V
V
0.8V
BOOT
OUT
BOOT
OUT
------------------- - R
T
is the on resistance of the bootstrap DMOS,
Q
ch
is calculated: if this drop is too high, or the
gate
H.V.
H.V.
arg
e
dson
C
C
TO LOAD
TO LOAD
BOOT
BOOT