BP2B Application Note

BP2B – Universal Gate Drive Prototype Board
Features:
 Complete isolated interface circuit with fault feedback
 2500VRMS isolation for control power and signals
 Standard AMP MTA .100” Input Signal and Control
Power Connectors
 Operates from a single 24 or 15VDC supply
 Compact Size 3” x 3” (76.2mm x 76.2mm)
Applications:
BP2B is designed for use with Powerex any
V1-Series IPM.
 Use Powerex DC to DC converters for
isolated control power:
VLA106-24151 for 24V input
Or
VLA106-15151 for 15V input
Ordering Information: BP2B-V is a kit containing a bare PCB with two VLA106-15151 DCto-DC converters.
Publication Date: 7/17/2014
Rev. 1
1
Application Notes
Description: The BP2B is a complete isolated interface circuit for dual V1-Series IPMs. This circuit features an
optical isolation interface for the control signals and isolated power supplies for the IPM’s built-in gate drive and
protection circuits. The isolated interface helps to simplify prototype development and minimize design time by
allowing direct connection of the IPM to logic level control circuits.
Note: User must supply Optocouplers and passive components to fully populate the BP2B (See Table 1)
Isolated DC to DC Converters:
In order to simplify the design and layout of the required control power supplies Powerex has introduced the
VLA106-24151, VLA106-15151 isolated DC-to-DC converters. Both DC-to-DC converters are designed to
produce an isolated 15V DC output. The VLA106-15151 operates from a 15VDC source and the VLA106-24151
operates from a 24VDC source. Both DC-to-DC converters use transformers to provide 2500VRMS isolation
between the primary and secondary side.
Controller Interface:
Figure 1 Typical Interface Circuit
Printed Circuit Layout:
Figure 2 shows the component layout of the BP2B interface circuit. The compact circuit board along with the IPM
provides a complete isolated dual channel driving circuit with short circuit, over temperature and under voltage
protection. This clearly demonstrates the advantage of using V1-Series Intelligent Power Modules. One
important feature of this PCB is the use of separate shield plane islands for each of the isolated driving circuits,
logic level interface, and control power supply. This layout is designed to prevent undesirable coupling of noise
between the control side and the floating gate drive channels. The BP2B PCB is designed to plug directly onto
the control pins of the V1-Series IPM. This configuration helps to maintain good noise immunity by providing
minimal interconnection distance.
Publication Date: 7/17/2014
Rev. 1
2
Application Notes
A typical controller interface for the BP2B is shown in Figure 1. An ON signal (IPM control input low) is generated
by pulling the respective control input low (GND) using a CMOS buffer capable of sinking at least 16mA (74HC04
or similar). In the OFF state, the buffer should actively pull the control input high to maintain good noise immunity.
Open collector drive that allows the control input to float will degrade common mode noise immunity and is
therefore not recommended.
Application Notes
Figure 2: Component Layout
Figure 3: Top Side Copper
Publication Date: 7/17/2014
Rev. 1
3
BP2B Circuit Explanation:
A complete schematic of the BP2B interface circuit is shown in Figure 5 and the bill of materials is given in Table
1. This circuit uses HCPL-4504 optocouplers to transfer logic level control signals between the system controller
and the IPM. The optocouplers provide galvanic isolation to completely separate the controller from the high
voltage in the power circuit. The BP2B also provides isolated control power supplies to power the IPMs built-in
gate drive and protection circuits. An ON signal is generated by turning on the internal optocoupler to pull the
IPM’s control input pin low.
The IPM’s fault output signals are transferred back to the system controller using low speed PS2501 optocouplers.
During normal operation the fault feedback line is pulled high to the +VL supply by the 4.7kΩ resistor R1. When
a fault condition is detected by the IPM it will immediately turn off the involved IGBT and pull its fault output pin
low. The IPM’s fault output has an open collector characteristic with an internal 1.5kΩ limiting resistor. Current
flows from the +15V local isolated supply to the low speed optocoupler. The optocoupler’s transistor turns on and
its collector pulls the fault feedback line low to indicate a fault. Slow optocouplers are used because they offer
the advantages of lower cost and higher current transfer ratios. High speed is not necessary because the IPM
disables a faulted device and produces a fault signal for a minimum of 1ms.
Publication Date: 7/17/2014
Rev. 1
4
Application Notes
Figure 4: Bottom Side Copper
Application Notes
Figure 5 Complete schematic of the BP2B interface circuit
Publication Date: 7/17/2014
Rev. 1
5
Table 1
Board Parts List
Designation
Description
Value
Example Type
DC supply filters. Low impedance
long life electrolytic.
82µF, 35V
Panasonic
EEUFC1V820
C5, C6
IC1, IC2
Local decoupling capacitors. Low
impedance multi-layer ceramic
15V out isolated DC/DC Converters
0.15µF, 50V
15V
Panasonic
ECUS1H154KBB
VLA106-15151
IC3, IC5
Control signal isolator (High-speed
optocoupler. High common mode
noise immunity - 10kV/µs minimum.
HCPL4504
IC4, IC6
Fault signal isolator, Low speed
optocoupler
NEC PS2501
R1
Fault signal pull-up
R2, R3
Fast opto LED current limiter (control
signal)
R4, R5
IPM control input pull-up
LED1, LED2
Fault indicator LED, high brightness
Panasonic
LN28WAL(US)
CN1
Input connector. MTA100 6 position
with locking ramp.
AMP 640457-6
CN2, CN3
Bottom entry 0.1" 5 position header
receptacle
MOLEX
22-14-2054
Publication Date: 7/17/2014
Rev. 1
Application Notes
C1, C2, C3,
C4
4.7kΩ,
0.25W
180Ω,
0.25W
10kΩ,
0.25W
6
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