L6743Q STMicroelectronics, L6743Q Datasheet - Page 10

• Manufacturer Part Number: L6743Q
• Description: IC MOSFET DRIVER HI CURR 10-DFN
• Manufacturer: STMicroelectronics
• Type: High Side/Low Sider

Specifications of L6743Q

• Configuration: High and Low Side, Synchronous
• Input Type: Non-Inverting
• Current - Peak: 2A
• Number Of Configurations: 1
• Number Of Outputs: 2
• Voltage - Supply: 5 V ~ 12 V
• Operating Temperature: 0°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-DFN
• Supply Voltage (min): 5 V
• Supply Current: 5 mA
• Maximum Power Dissipation: 2250 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• Number Of Drivers: 2
• Flexible Gate-drive: 5V to 12V compatible
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Delay Time: -
• High Side Voltage - Max (bootstrap): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Device description and operation
10/17
When designing an application based on L6743, L6743Q it is recommended to take into
consideration the effect of external gate resistors on the power dissipated by the driver.
External gate resistors helps the device to dissipate the switching power since the same
power P
resulting in a general cooling of the device.
Referring to
stage with two different MOSFETs: P-MOSFET to drive the external gate high and N-
MOSFET to drive the external gate low (with their own R
R
(C
MOSFET to reach the driving voltage (PVCC for HS and VCC for LS). This capacitance is
charged and discharged at the driver switching frequency F
The total power Psw is dissipated among the resistive components distributed along the
driving path. According to the external gate resistance and the power-MOSFET intrinsic
gate resistance, the driver dissipates only a portion of Psw as follow:
The total power dissipated from the driver can then be determined as follow:
Figure 6.
P
P
P
lo_LS
SW HS
SW LS
G_HS
=
LS DRIVER
–
–
P
DC
). The external power MOSFET can be represented in this case as a capacitance
, C
SW
=
+
=
G_LS
LGATE
P
1
-- - C
2
GND
VCC
1
-- - C
2
will be shared between the internal driver impedance and the external resistor
SW HS
Figure
⋅
Equivalent circuit for MOSFET drive
⋅
) that stores the gate-charge (Q
–
GLS
GHS
R
GATELS
⋅
+
6, classical MOSFET driver can be represented by a push-pull output
⋅
VCC
PVCC
P
LS MOSFET
SW LS
2
–
R
⋅
2
C
ILS
Fsw
⋅
GLS
Fsw
⋅
⎛
⎝
⋅
------------------------------------------------------------- -
R
⎛
⎝
hiLS
--------------------------------------------------------------- -
R
hiHS
+
R
+
R
GateLS
R
hiLS
R
GateHS
hiHS
G_HS
+
R
, Q
+
iLS
R
G_LS
iHS
+
DS(on)
HS DRIVER
------------------------------------------------------------- -
R
+
loLS
) required by the external power
SW
--------------------------------------------------------------- -
R
loHS
: R
.
+
HGATE
PHASE
BOOT
R
VCC
hi_HS,
R
+
GateLS
loLS
R
R
GateHS
loHS
R
R
+
lo_HS
GATEHS
R
L6743, L6743Q
+
iLS
HS MOSFET
R
, R
⎞
⎠
iHS
C
R
hi_LS,
GHS
IHS
⎞
⎠