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