General Description
The EVDD404 evaluation board is a general-purpose circuit
board designed to simplify the evaluation of the IXYS
IXDD404, IXDI404 and IXDN404 gate drive ICs, as well as to
provide a building block for power circuit development.
Either the DIP-8 (PI) or SO-16 (SI-16) gate driver package
types may be installed in the driver (the DIP-8 package is
factory installed). The board enables the user to drive
MOSFETs or IGBTs in TO-220, TO-247, TO-264 or SOT-227
packages. The evaluation board design allows these
MOSFETS to be attached to a heat sink, and in so doing the
board assembly can be used as a ground referenced, low
side power switch for both single-ended and push-pull
configurations. Circuitry for the Tri-State function is included
on the evaluation board.
Figure 1 is a photograph of the IXDD404 Evaluation Board
loaded with an IXDD404PI DIP-8 driver and a SOT-227
MOSFET. The low level inputs are shown on the left side of
the board. CONTROL is a TTL high true input which controls
the on or off state of the power switch Q1, Q2, or Q3.
ENABLE is a low true input, which controls the Tri-State
output. (The Tri-State output is not used with the IXDI404
and IXDN404 ICs). VCC-IN is the low voltage, (8-25V) power
input, (see Figure 3 below). Figure 2 illustrates the MOSFET
mounting of a TO-220, TO-247, or TO-264 device. The
MOSFET is mounted on the back side of the PCB. A large
through hole is provided so that the device can be attached
to a heat sink. The SOT-227 (shown in the photograph) is
mounted in a similar manner.
Circuit Operation
The schematic diagram for the evaluation board is shown in
Figure 4. The control gate is applied to R4 then on the input
pins 2 and 4 of the IC U1 (or to pins 2 and 7 of U2, if loaded
in place of U1). This signal input is followed in time by the
output pins 5 and 7 of U1 (or pins 10, 11, 14 and 15 of U2, if
loaded). Pins 1 and 8 of U1 and U2 are attached to +VCC
via a de-coupling network comprised of R1, C3 and R10,
C4. Pin 3 of U1 and pins 4 and 5 of U2 are attached to the
circuit ground plane. This is the preferred arrangement of
the bypassing for the Vcc input power. The enable pins 1
and 8 of U1 and U2 are attached to the drain of Q4. This
device is used to level translate and provide an invert
function for the Tri-State mode. The drain of Q4 is also
attached to the gate of the MOSFET thru RA1 and DA1. In
the Tri-State mode the turn off time of the power MOSFET is
determined by the time constant of the input gate
capacitance C
IXDD404 data sheet for additional information on this mode
of operation.
The U1 output is available at pins 5 and 7 of U1 (or pins 10,
11, 14 and 15 of U2, if loaded). These are attached to the
MOSFET via the two one-Ohm resistors R5 and R7. The
values of these resistors may be changed to optimize the
performance of the specific device being driven. The board
is designed to parallel the two outputs of the IXDD404 IC,
generating up to 8A of output current. If only one output
Copyright © IXYS CORPORATION 2001
iss
and the value of the resistor RA1. See the
EVDD404
IXDD404, IXDI404 And IXDN404 Gate Driver IC Evaluation Board
Figure 2 - EVDD404 Side View Showing Power Device
Installed In A High-Power Configuration
Figure 3 - Input Pin-Out Table
channel is desired, the other channel may be disabled by
removing either R5 or R7, thereby disconnecting that
channel's output from the MOSFET gate.
There are three test points on the board: Control, Gate and
Drain. These allow the user to easily attach an oscilloscope
probe and the associated ground to the circuit to verify
performance.
Figure 1 - EVDD404 Evaluation Board
SOT-227 Device Installed For Illustration Purposes Only
The EVDD404 is supplied with the DIP-8 (PI) device in-
stalled. To use the evaluation board with a different package
type, the installed device must be removed, and the new
device installed in the appropriate location.
CONTROL
ENABLE
VCC-IN
INPUT
GND 3
GND1
GND2
First Release
Part Number
EVDD404
EVDI404
EVDN404
Heat Sink
LOW = True, HIGH = Tri-State Mode
Control Input - 3V into 1K Ohms
ORDERING INFORMATION
VCC input - 8V to 25V
FUNCTION
Ground 1
Ground 2
Ground 3
Installed Device
IXDD404PI DIP-8
IXDI404PI DIP-8
IXDN404PI DIP-8
TO-220, TO-247,
TO-264, or SOT-227
Evaluation PCB
Kapton Insulator