Operating principles | Main characteristics | Modules & implementation | Tradeoffs & considerations | Product comparison
To meet a diverse range of applications and needs, Hamamatsu provides a full lineup of many MPPC types in different pixel sizes, photosensitive areas, and packages. This selection guide is meant to serve as a suggestion on how to navigate these various options. When in doubt, it is always best to calculate your signal-to-noise ratio in your specific application and operating conditions. You can also contact any one of our MPPC product specialists using the email address below.
We review selecting an MPPC using the following considerations:
- Product series type and wavelength
- Active area size
- Microcell size
- Package type
- Measurement techniques and implementation considerations
- Signal-to-noise calculations
Email: HC_MPPC_Group@hamamatsu.com
1. Selecting a product series
Hamamatsu’s product series is differentiated mainly by the spectral sensitivity, namely a UV/Blue sensitive type, Green Enhanced Type, and NIR Enhanced type. The different sensitivity series also have varying noise characteristics.
There are also distinctions in the operating voltage, available microcell sizes, and package design for the various series. Below is a brief summary comparison. For a full product lineup and comparison, please refer to the table in the back.
When selecting an appropriate series, determine the main wavelength (or wavelengths) of interest and whether you have any noise or operating restrictions.
| MPPC Series | Series Part Number | Vbr (typ.) [V] | Peak Wavelength [nm]0 | Dark Counts per mm^2 [kcps] * | Specialization |
| UV-Blue Enhanced | S1336x Series | 53 ± 5 | 450 | 45 | General blue measurement. Different channel, microcell, and package types available. |
| Low Voltage (UV-Blue) | S1416x Series | 38 | 450 | 67nA (dark current) |
Scintillation type. Center hole wirebond package only. |
| Green Enhanced | S1442x Series | 42 ± 5 | 600 | 175 | Vis to NIR. Different channel, microcell, and package types available. |
| NIR Enhanced | S1372x Series | 57 ± 5 | 660 | 295 | NIR. Available in small channel and microcell size. |
* Typical at 25 deg C. Based on 25µm microcell size
Figure 12: PDE vs Wavelength for Different Series Types
2. Selecting an active area size
Hamamatsu offers 1x1mm to 6x6mm for single channel sizes. When considering a channel size, consider tradeoffs between light collection, dynamic range, timing requirements, and noise. As the channel size becomes larger, the noise increases and the timing resolution (jitter) suffers. However, a larger channel size will allow for easier light collection, and it also means more area for microcells which could increase your dynamic range.
We also offer a variety of array sizes and shapes. The total array size that we can offer is up to 25mmx25mm on a single PCB using any combination of channel size and number (for example, a 4x4ch of 6x6mm or a 8x8ch of 3x3mm).
Figure 13: Active area tradeoffs
Figure 14: Discrete SiPM and arrays
3. Selecting a microcell size
The microcell size drives a few different parameters: the gain slope (gain increase vs. voltage), the linearity, the recovery time of the microcell, the signal pulse shape, and the fill factor. Most of these parameters change because as microcell size changes, its capacitance changes. Large microcell sizes will have a steeper gain slope and vice versa. The microcell size will also affect the signal pulse shape and recovery time for the same capacitance change.
For a given active area, varying microcell sizes will affect the linearity and fill factor. As more microcells are available for detecting light in a given area (therefore reducing your microcell size), they also have a smaller fill factor. Dead space starts to increase as the microcell gets smaller and smaller. The decreasing fill factor manifests itself as a drop in PDE.
Figure 15: PDE for various microcell sizes
Figure 16: Linearity
Figure 17: Pixel size tradeoffs
4. Selecting a package type
The package type will greatly depend on your application. Surface mount devices (SMD) are available for ultra-compact and small dead space (consumer) packaging. We have packages that are four side buttable which could make a 2D or 1D array. Hamamatsu also makes TE cooled packages for low dark counts and temperature control. Hamamatsu completely owns our packaging process, so please let us know if you have any custom requests.
Figure 18: Different Package Configurations
5. Measurement techniques
The method of readout that you choose will be dependent on your light levels, required dynamic range, and other factors (like time resolution, etc.). If the pulses are crowded and overlapping, the continuous wave mode is appropriate. If the pulses are distinguishable, then photon counting — analog or digital — is preferable.
Analog and photon counting
- Analogously to a photomultiplier tube, an SiPM can operate in two distinct modes: continuous wave and photon counting. In the former, the output pulses are neither detected nor counted individually; instead, an analog output current is measured. In the latter, the individual pulses are either counted (digital photon counting) or integrated to yield the charge released in Geiger discharge (analog photon counting). The choice of the detection technique depends, among other factors, on the frequency and duration of the output pulses.
- Photon counting has the following benefits:
- Uses a discriminator and pulse shaper to detect pulse peaks. Therefore, it effectively removes low amplitude electronic noise (amplifier and readout circuit).
- It is immune to gain fluctuations which effectively removes the excess noise factor term from the SNR equation.
- These result in the lowest possible detection limits.
- Analog measurement has the following benefits:
- High dynamic range since it can handle pulse pile up
- High timing resolution
- Simpler circuit design
Figure 19: Photon counting vs. analog measurement dynamic ranges
6. Signal-to-noise calculations
When in doubt, it is best to calculate your signal-to-noise ratio (SNR) for your specific operating conditions. The SNR will give you a measure of merit for your detector comparisons. Please refer to the detailed description of SNR and how to calculate SNR on the link below.
https://www.hamamatsu.com/resources/pdf/ssd/mppc_kapd9005e.pdf
If you need any assistance, please do not hesitate to contact us:
Technical information and support
Monday - Friday, 9:00 am - 5:00 pm (EST)
Phone: (908) 231-0960
Email: HC_MPPC_Group@hamamatsu.com