PAC5253_17 Datasheet, PDF (39/71 Pages) Active-Semi, Inc – Power Application Controller

PAC5253
Power Application Controller
Figure 12-2. Typical Gate Driver Connections
PAC5253
DXBx
DXHx
DXSx
DRLx
V
P
V
IN
(To loads/inductors.)
Table 20. Power Driver Resources by Part Number
LOW-SIDE GATE
DRIVER
PART
NUMBER
SOURCE /
DRLx SINK
CURRENT
HIGH-SIDE GATE DRIVER
DXHx
MAX
SUPPLY
SOURCE/
SINK
CURRENT
PAC5253 4
1A/1A
3
600V 0.25A/0.5A
OPEN-DRAIN DRIVER
OMx
2 (23V/ 40mA)
The ASPD includes built-in configurable fault protection for the internal gate drivers.
12.3.1. Low-Side Gate Driver
The DRLx low-side gate driver drives the gate of an external MOSFET or IGBT switch between the low-level VSSP power
ground rail and high-level VP supply rail. The DRLx output pin has sink and source output current capability of 1A. Each
low-side gate driver is controlled by a microcontroller port signal with 4 configurable levels of propagation delay.
12.3.2. Ultra-High-Voltage Gate Driver
The DXHx ultra-high-voltage high-side gate driver drives the gate of an external MOSFET or IGBT switch between its
low-level DXSx driver source rail and its high-level DXBx bootstrap rail. The DXSx pin can go up to 600V. The DXHx
output pin has 0.5A sink and 0.25A source output current capability. The DXBx bootstrap pin can have a maximum
operating voltage of 20V relative to the DXSx pin. The DXSx pin is designed to tolerate momentary switching negative
spikes down to -10V without affecting the DXHx output state. Each ultra-high-voltage high-side gate driver is controlled by
a microcontroller port signal.
For bootstrapped high-side operation, connect an appropriate capacitor between DXBx and DXSx and a properly rated
bootstrap diode from VP rail to DXBx.
12.3.3. High-Side Switching Transients
Typical high-side switching transients are shown in Figure 12-3(a). To ensure functionality and reliability, the DXSx and
DXBx pins must not exceed the peak and undershoot limit values shown. This should be verified by probing the DXSx and
DXBx pins directly relative to VSS pin. A small resistor and diode clamp for the DXSx pin can be used to make sure that
the pin voltage stays within the negative limit value. In addition, the high-side slew rate dV/dt must be kept within ±50V/ns
for DXSx. This can be achieved by adding a resistor-diode pair in series, and an optional capacitor in parallel with the
power switch gate. The parallel capacitor also provides a low impedance and close gate shunt against coupling from the
switch drain. These optional protection and slew rate control are shown in Figure 12-3(b).
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Rev 1.18‒December 29, 2016