Motor drive applications demand higher voltages and current than most ICs and microcontrollers can handle. To address the problem a variety of new drivers have been developed. These include IGBTs, MOSFETs, and Intelligent Power Modules (IPMs). These drivers depend on the galvanic isolation that optocouplers provide to protect their microcontrollers from the power surges, spikes, ground loops, and electrical noise their motors generate. Key requirements for optocouplers in these kinds of applications include:
- High Current Output/High Speed
- High Common Mode Rejection (CMR)
- Compact Size
- Repeatability
- Reliability
NEC PS9552 Series optocouplers are optimized for IGBT, MOSFET and IPM driver isolation. They feature a GaAlAs light-emitting diode on the input side of the chip and a photo diode, signal processing circuitry, and power transistors on the output side. They offer high common mode transient immunity, large peak output current, and fast switching speeds. Under Voltage Lockout Protection (UVLO) with hysteresis is also a standard feature, plus all PS9552 devices are housed in special RoHS-compliant white epoxy packages designed to limit heat absorption in high current applications.
Four models are available: An 8 pin DIP and an 8 pin gullwing-style package for surface mount, plus 8 pin DIP and gullwing packages with 8mm creepage designed to meet international safety certification standards. |
