ACPL-W341-500E Datasheet, PDF (15/19 Pages) AVAGO TECHNOLOGIES LIMITED – 3.0 Amp Output Current IGBT Gate Drive Optocoupler with Rail-to-Rail Output Voltage in Stretched SO6

Rail-to-Rail Output
Figure 23 shows a typical gate driver’s high current output
stage with 3 bipolar transistors in darlington configuration.
During the output high transition, the output voltage rises
rapidly to within 3 diode drops of V_CC. To ensure the V_OUT
is at V_CC in order to achieve IGBT rated V_CE(ON) voltage. The
level of V_CC will be need to be raised to beyond V_CC+3(V_BE)
to account for the diode drops. And to limit the output
voltage to V_CC, a pull-down resistor, R_PULL-DOWN between
the output and V_EE is recommended to sink a static current
while the output is high.
ACPL-P341 uses a power PMOS to deliver the large current
and pull it to V_CC to achieve rail-to-rail output voltage
as shown in Figure 24. This ensures that the IGBT’s gate
voltage is driven to the optimum intended level with no
power loss across IGBT even when an unstable power
supply is used.
ANODE 1
NC 2
CATHODE 3
NC 4
8 VCC
7 ^VOUT
RG
6
RPULL-DOWN
5 ^VEE
Figure 23. Typical gate driver with output stage in darlington configuration
ANODE 1
NC 2
CATHODE 3
6 V_CC
5 V_OUT
4 ^VEE
Figure 24. ACPL-P341/W341 with PMOS and NMOS output stage for rail-to-rail output voltage
15