Contents[Hide]

Active bypass diodes

The need for lossless diodes

The solar bike PV panels, in contrast to common PV panels, have a particular need for bypass diodes. That is because shade appears often and the PV panel efficiency during shadow must be optimized. Cool bypass switch "diodes" such as the LX2400 and the SPV1001T40 are the ultimate solutions here.

SM74611

Smart bypass diode from Texas Instruments. The average forward voltage drop is 30 mV at 5A, 85°C. Introduced in dec. 2012.

SM74611 smart bypass diode from Texas Instruments
SM74611 smart bypass diode from Texas Instruments

SPV1001

Cool bypass switch (CBS) from STMicroelectronics.

SPV1001T40

  • Available in TO220, D2PAK and MLPD
  • Very low profile with MLPD package, less than 1mm, to laminate device directly on the panel
  • Available since October 2010

SPV1001T40 (TO-220).

Vf [V] Vf max i [A] Tj [°C]
0.08 5 25
0.11 8 25
0.27 8 125

LX2400

The LX2400 IDEALSolarTM Bypass Diode with Microsemi’s patented CoolRUNTM technology provides a bypass diode with the industry’s lowest forward voltage drop resulting in negligible heat generation. The LX2400 temperature range is -65°C to +165°C. Load the datasheet here. The package is smaller compared to the TO-220. The LGA package dimensions are 7.5mm x 11.5mm.

LX2400 Cool bypass switch from Microsemi
LX2400 Cool bypass switch from Microsemi

Vf [V] Vf max i [A] Ta [°C]
0.05 10 80

LX2400 bypass diode forward voltage

As we can see, the LX2400 has lower forward voltage drop than SPV1001.

Super barrier rectifier bypass diodes

A Super Barrier Rectifier (SBR) is effectively a MOSFET with its gate and source shorted together. They have a very low forward voltage drop.

Super Barrier Rectifier

SBR30U30CT

30A Super Barrier Rectifier from manufacturer Diodes.

SBR30U30CT

  • Connecting the two diodes parallel halves the current to 2.5A per pin.
  • Price about $2
Vf [V] Vf max i [A] Tj [°C]
0.19 2.5 125
0.24 5 125
0.41 0.45 15 25
0.34 0.37 15 125

SBR20U40CT

20A ultra low Vf Super Barrier Rectifier from manufacturer Diodes.

SBR20U40CT

  • Connecting the two diodes parallel halves the current to 2.5A per pin.
  • Price about $1.15
Vf [V] Vf max i [A] Tj [°C]
~0.27 2.5 125
~0.32 5 125
0.47 10 25
0.41 0.44 10 125

PDS1040L-13 / PDS1045-13

10A low Vf schottky barrier rectifier from manufacturer Diodes.

PDS1040L-13 package PowerDI®5

Vf [V] Vf max i [A] Tj [°C]
0.39 5 25
0.28 5 125
0.41 0.46 6 25
0.30 0.35 6 125

SBR10U45SP5

10A Super Barrier Rectifier for solar panels from manufacturer Diodes. Designed as Bypass Diodes for Solar Panels.

PowerDI®5

  • Designed in accordance to Solar Industry Safety Standards (IEC61730-2, IEC61215-2)
  • Large safe operating area (SOA) with maximum selectively rated 200°C junction temperature for higher reliability
  • Low profile height of 1.1mm for possible integration into the solar panels
  • Low leakage current <2mA @85ºC
Vf [V] Vf max i [A] Tj [°C]
0.29 5 125

SBR10U45SD1

Same as SBR10U45SP5 but with case DO-201AD.

DO-201AD

Do you have any comments? Please let me know.
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.