Alpha PD Series

  • Alpha Electronics

Product Features

  • Ultra-precision power resistor
  • Resistance range form 0.1Ω to 10kΩ
  • Tolerance from ±0.02% to ±5%
  • TCR of ±2.5 ppm/°C, ±5 ppm/°C or ±15 ppm/°C
  • Power rating of upto 8W (on a heat sink at 25°C)
  • Temperature range from -55°C up to +155°C


The PD ultra-precision TO-220 through-hole power resistor series from Alpha Electronics offers a power rating of up to 8W on a heat sink or 1.5W in free air (at 25°C) over a wide resistance range of 0.1Ω to 10kΩ. By utilising Alpha’s Bulk Metal® foil resistor technology, they are able to offer low temperature coefficients down to ±2.5 ppm/°C between the resistance range 5Ω and 10kΩ as well as tight tolerances down to ±0.02% between 25Ω and 10kΩ.

  • Ultra-precision through-hole power resistor
  • Each resistor is available in any resistance between 0.1Ω and 10kΩ
  • TO-220 through-hole package
  • Power rating of 8W on a heat sink or 1.5W in free air at +25°C
  • Tight tolerances as low as ±0.02% available between 25Ω and 10kΩ
  • Tight TCR available of ±2.5 ppm/°C between 5Ω and 10kΩ
  • Maximum working voltage of 250V
  • Maximum working current of 4A
  • Maximum rated operating temperature +25°C
  • Temperature range from -55°C up to +155°C


The PD ultra-precision power resistor series exhibits excellent high frequency characteristics thanks to Alpha’s Bulk Metal® foil resistor technology, making them suitable for the most demanding precision applications. Their standard TO-220 package is commonly used for power semiconductor devices making them ideal for new power designs.

Pin pitch for the Alpha PD series is 5.08 ±0.5mm.


The below table gives a summary of the specifications and options available for the Alpha PD series:

Alpha PD Specifications
* Symbols parenthesized are for part number composition
✝ Resistance figures are the values obtained by measuring the leads at point 5.08 ±0.6mm away from the root
** For heat sinking, an aluminium chassis in 152.4 (L) x 101.6 (W) x 50.8 (H) x 1.0mm (T) shall be used