We all know that many companies' purchasing engineers don't know which pins are the N-type, M-type and P-type of laser diodes. Today, Xiaobian will give you a brief talk.

How to recognize N-type package?

This is the most common packaging method, especially the red light and infrared LD of TO package are mostly N-type.

The way to judge is simple:

The shell (metal shell) is connected with the Cathode (K).

The middle pin is the Anode (A).

The gold wire is drawn from the chip to the middle pin.

The base is a common terminal.

How to recognize P-type package?

P-type and n-type are just the opposite.

The shell (metal shell) is connected with the anode (a)

The middle pin is connected with the negative pole (K)

The gold wire is pulled from the chip to the housing (positive electrode).

How to recognize M-type package?

M-type is common in some national brands or some special products, and its structure is similar to a variant between N-type and P-type, and sometimes manufacturers decide for themselves.

There are two mainstream definitions in the industry:

Shell = positive pole, middle pin = one pin for positive pole and negative pole independently.

In other words, it is a structure of double positive electrode and single negative electrode.

Why is there an M-shape?

Mainly to enhance heat dissipation and current path stability, some high-power infrared LD will use this packaging method to make the anode more stable and lower resistance.

What I have introduced above is the relationship among N-type, M-type and P-type of laser diode. I hope you will have a clear understanding after reading it.