Broadcom's SiPM data sheets detail key performance parameters of their silicon photomultipliers - a key parameter is Gain which is explained in more detail below.
When a SPAD detects a photon it produces a standardised charge with a very low Excess Noise Factor close to 1. The Geiger discharge of a SPAD is proportional to the applied Overbias, i.e. VOB = VBias – VBreakdown and the SPAD capacitance.
| Gain = ((CSPAD • VOB) / e) ∝ ε • VOB | |||
| CSPAD = SPAD Capacitance | VOB = Overbias | ε = Geometric Efficiency | e = Elementary Charge |
The gain of Broadcom's latest NUV-MT SiPMs is 7.3x106 at 12V Overbias and even single photon events result in amplitudes of several mV across a 50Ω load.
The graph below shows SiPM gain for Broadcom's NUV-MT technology
Bear in mind that PDE, Dark Count Rate, Crosstalk and Afterpulsing also increase with increasing Overbias meaning Noise, Saturation and Linearity are all affected. Therefore it should not be assumed that higher Overbias = higher Gain = optimum performance in any given application.
The correlation between Gain, Crosstalk probability, Dark Count Rate, PDE and Overbias is discussed a new application note NUV-MT Performance Correlation and Broadcom have produced a number of other helpful application notes which can be accessed below.
 |
Broadcom's SiPM Family overview |
 |
Product Brief, NUV-MT SiPM range |
|
A Brief Introduction to SiPMs |
|
Working with Broadcom SiPMs |
|
NUV-MT Performance Correlation |
|
NUV-MT Single-Photon Measurements |
|
SiPM Characteristics for PMT Users |
For more detail please visit the Support pages using the links in this article and on the right hand side of this page.
