HP diode coding

HP diodes appear to follow a regular coding scheme. Although this is not always followed, it may help in identifying diodes and package styles if used with caution. Not all HP diodes follow this scheme, so beware!

The general type number scheme is: HSMX-123#
HSM stands for HP Suface Mount, I suppose!
X is either S for a schottky diode or P for a PIN diode.
is a letter for a SOT323 package and a number for a SOT23 device.
It denotes the internal arrangement - single, common anode pair, quad, etc. The digit of the code marked on the package itself usually corresponds to the package style (#) number. The numbers and letters correspond to the following arrangements:

 Device style


Printed on
Single diode - standard 0 B 0 C
Single diode – reverse 1 A 1 K
Dual series - standard 2 C 2 D
Dual series – reverse 2 C 2 Z
Common anode pair 3   3 A
Common cathode pair 4   4 B
Unconnected pair 5   5 S
Ring Quad 7   7 RQ
Bridge Quad 8   8 BQ
Dual Anode     A Y
Dual Cathode     B J

Last Updated on 01/06/06