Datasheet
UCC27323
GND
1
2
3
4
INB
INA
7
6
5
8
OUTA
VDD
OUTB
INPUT
1 µF
Ceramic
100 µF
Aluminum
Electrolytic
D
SCHOTTKY
V
DD
C2
1 µF
V
SNS
R
SNS
0.1 W
C3
100 µF
10 W
+
V
5.5 V
SUPPLY
D
4.5 V
ADJ
UCC27323
GND
1
2
3
4
INB
INA
7
6
5
8
OUTA
VDD
OUTB
INPUT
1 µF
Ceramic
100 µF
Aluminum
Electrolytic
D
SCHOTTKY
V
DD
C2
1 µF
V
SNS
R
SNS
0.1 W
C3
100 µF
10 Ω
UCC27323-Q1, UCC27324-Q1, UCC27325-Q1
www.ti.com
SLUS678A –MARCH 2008–REVISED APRIL 2012
Source/Sink Capabilities During Miller Plateau
Large power MOSFETs present a large load to the control circuitry. Proper drive is required for efficient, reliable
operation. The UCC2732x drivers have been optimized to provide maximum drive to a power MOSFET during
the Miller plateau region of the switching transition. This interval occurs while the drain voltage is swinging
between the voltage levels dictated by the power topology, requiring the charging/discharging of the drain-gate
capacitance with current supplied or removed by the driver.[1]
Two circuits are used to test the current capabilities of the UCC27323 driver. In each case, external circuitry is
added to clamp the output near 5 V while the device is sinking or sourcing current. An input pulse of 250 ns is
applied at a frequency of 1 kHz in the proper polarity for the respective test. In each test, there is a transient
period when the current peaked up and then settled down to a steady-state value. The noted current
measurements are made at a time of 200 ns after the input pulse is applied, after the initial transient.
The circuit in Figure 2 is used to verify the current sink capability when the output of the driver is clamped at
approximately 5 V, a typical value of gate-source voltage during the Miller plateau region. The UCC27323 is
found to sink 4.5 A at V
DD
= 15 V and 4.28 A at V
DD
= 12 V.
Figure 2.
The circuit in Figure 3 is used to test the current source capability with the output clamped to approximately 5 V
with a string of Zener diodes. The UCC27323 is found to source 4.8 A at V
DD
= 15 V and 3.7 A at V
DD
= 12 V.
Figure 3.
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