What is difference between single and common cathode configuration? If I want to use 2804 for rectifying, will it act as 2800?

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HSMS2800 https://datasheet.octopart.com/HSMS-2800-BLKG-Avago-datasheet-7087620.pdf


A 2804 is two 2800's, with their cathodes connected together, put in the same package. You could just use one of them, or you could use both in parallel.

  • \$\begingroup\$ That means, if I do not solder one of two terminal side of 2804 diode, it will act as 2800. Am I right? \$\endgroup\$
    – Max Rock
    Apr 4 '19 at 14:53
  • \$\begingroup\$ These are not power diodes, only small signal, for low current<5mA use. Do you understand Max? \$\endgroup\$ Apr 4 '19 at 15:02
  • \$\begingroup\$ @SunnyskyguyEE75 I am working on project related to rectenna. According to many researches I looked through, mostly used diodes were HSMS 28xx family. I am stuck on choosing right diodes. Most diodes of HSMS 28xx family are obsolete. That is why I am looking for trade-off. What I found HSMS 2804 was not out of stock. \$\endgroup\$
    – Max Rock
    Apr 4 '19 at 15:35
  • \$\begingroup\$ @SunnyskyguyEE75 a bit different question, more broadly about my problem I posted here(electronics.stackexchange.com/questions/428821/…) \$\endgroup\$
    – Max Rock
    Apr 4 '19 at 15:42
  • \$\begingroup\$ hmm that schematic does not reflect your readings. "circuit gave output 14.5V and 45uA on 200 Ohms load." does not make sense. 45uA on 200 Ohms is 9mV \$\endgroup\$ Apr 4 '19 at 15:48

As you can see in the table, every package has identical single diode specifications.

But your question is "If I want to use 2804 for rectifying, will it act as 2800?"

The temperature rise will be double sharing one package for two diodes.

Answer: Yes for peak currents <=1mA
No , if near Ip=10mA do not use if temp rise exceeds 70'C above worst case board temp.

Although they have identical characteristics, now it means the dual diode package must share the same thermal resistance of;
500°C/W for SOT-23 and 150°C/W for SOT-323

You must work out the temp rise, but it means your DC load must be << 1mA since the diode peak current into a storage cap with 10% ripple will be 10mA


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