Resistors withstand high pulses in a compact design
Designed for performance-critical applications, the HPWC (high pulse withstanding chip) range of high energy surge resistor products have been announced by TT Electronics.
The high pulse resistors are designed to maximise the level of surge performance available in a single-sided flat chip design. The HPWC range is suitable for protection and discharge applications in compact power supplies and power control circuits where a resistance tolerance of five per cent is required.
Available in four sizes from 0805 to 2512, HPWC resistors withstand up to 6.5kV peak for a 1.2/50-micro second surge and up to 3kW for a 0.1-milli second pulse. The product is an evolution of TT Electronics’ PWC (pulse withstanding chip) resistors, explains the company, making the distinction that the resistance value is adjusted by precise process control rather than by laser trimming. This process maximises and improves the level of surge performance available in a single-sided flat chip design. Resistance values available are from 1R0 to 100k. The four sizes are available with ratings from 0.25 to 2W.
The resistors providing enhanced ability to absorb high energy surges, making them suitable for power supplies, circuit breakers, motor drives and medical monitor input protection. The thick-film resistors are aimed at designers of compact surface mount device circuits in power conversion, motion control and protection applications in the industrial and medical markets.
According to TT Electronics, the factors driving the demand for this type of product are the growth in distributed power management and motion control in industrial and automated systems, together with pressure to reduce size and weight whilst increasing surge protection for EMC regulatory compliance and product reliability.
TT Electronics’ HPWC resistors’ compact PCB footprint minimises use of PCB area, whilst the absence of laser trimming means no current crowding and a consequential avoidance of hot spots, to improve reliability. Significantly, adds TT Electronics, the HPWC series offers a higher surge performance than key competing parts from other companies.
