Home / 905 nm APD alternative
905 nm APD alternative: a qualified second source, not an emergency
Status: active · single-sourced · a 905 nm receiver worth dual-sourcing
The 905 nm avalanche photodiodes from First Sensor (the AD500-9 family) and Hamamatsu are not discontinued. They are active, widely used receive-path parts. So this is not an end-of-life page — it is a supply-risk page. If a 905 nm APD sits on your LiDAR or laser-rangefinder production line, a single source for the receiver is the risk; qualifying a second one is the fix.
The short answer
The functional second source for a First Sensor AD500-9 / Hamamatsu 905 nm APD is LumeLiDAR's TO46-905APD series: 905 nm avalanche photodiodes in a TO46 can, with 230 µm and 500 µm active areas. Both sit at 905 nm with the same 100–200 V breakdown range. The package and exact gain curve are confirmed against your drawing and on your bench before you commit — which is the part of a second-source qualification nobody should skip.
Status of the original part
The First Sensor AD500-9 (now part of OSI Optoelectronics) and the equivalent Hamamatsu 905 nm APDs are active parts. The facts that matter for a second-source decision:
- Status: active — not discontinued, not end-of-life. Both suppliers list their 905 nm APDs as current products.
- Package: the AD500-9 family ships in TO52S1 metal can, LCC6.1F surface-mount and bare die; Hamamatsu ships its own ceramic and metal-can forms.
- Rating: peak response at 905 nm, Ø500 µm active area (0.196 mm²), gain 50–60 (up to 200), 160–200 V breakdown, >80 % quantum efficiency across 750–910 nm, 0.55 ns rise time, ~1.2 pF capacitance.
- Their pitch is NIR-enhanced silicon with a guard-ring structure: low dark current (<2 nA at M = 100) and a slow, low-noise multiplication curve.
None of that argues for replacing it. What argues for qualifying a second source is that every one of those numbers comes from exactly one supplier.
The two parts, compared
All figures below are from the published datasheets: the First Sensor AD500-9 datasheet and the LumeLiDAR APD datasheet.
| Parameter | AD500-9 (First Sensor) |
TO46-905APD-500-1 (LumeLiDAR) |
|---|---|---|
| Peak wavelength | 905 nm | 905 nm |
| Active area | Ø500 µm (0.196 mm²) | 500 µm |
| Package | TO52S1 / LCC6.1F / bare die | TO46 metal can, 2-pin |
| Breakdown voltage | 160–200 V | 100–200 V |
| Gain (M) | 50–60 typ (up to 200) | Per bias — confirmed on samples |
| Match type | — | Functional; same wavelength, geometry confirmed against your drawing |
| Supply status | Active | Active — samples from stock |
The AD500-9 is offered in TO52, LCC6.1F and bare-die forms; LumeLiDAR ships the TO46 can. The 230 µm version (TO46-905APD-230-1) covers designs with a smaller active area, and a shielded variant handles high-ambient-light outdoor use. The exact capacitance and gain curve are confirmed on samples against your receiver front-end, not on the datasheet headline.
AD500-9, First Sensor and Hamamatsu are trademarks of their respective owners. They are named on this page solely to identify the device a customer may already be using. Their use is descriptive and does not imply any affiliation with, authorisation by, sponsorship by or endorsement from those owners. LumeLiDAR supplies its own parts; it does not supply, repackage or pass off original parts of other manufacturers.
Your options, graded honestly
1. Stay single-sourced — if that is a conscious call
If your volumes are low, your lead times are comfortable, and a single supplier covers your product's life, there is no urgent reason to change. A second source is a project with a cost; only you know whether the risk justifies it.
What we will not do is dress this up as an emergency. It isn't one.
2. Qualify TO46-905APD as the second source
Same 905 nm, same 500 µm (or 230 µm) active area, same 100–200 V bias range. The qualification itself is the work: package and gain curve confirmed against your receiver front-end, then samples on your bench for responsivity and capacitance.
That is the only part we do, and we do it before you order.
3. If the problem is the whole link
A 905 nm receiver is only half the optical BOM. If you also want the emitter and the driver quoted as one, the transmit-side second sources are the RLD90QZW3 and SPL TL90AT03 alternatives — or ask us to bundle source + receiver + driver per design.
One optical BOM, one supplier relationship.
What "functional second source" does and does not mean
Functionally, the two parts are at the same wavelength and active-area class. "Functional" — as opposed to "pin-to-pin" — is the honest grade when the package needs a confirm against your drawing first. Specifically:
- The optical and bias path matches: 905 nm, 500 µm (or 230 µm), 100–200 V
- The package — TO46 can vs TO52 / LCC6.1F / bare die — is confirmed against your mechanical drawing
- The capacitance and gain curve are measured per unit on your own test bench
Responsivity under your bias conditions is confirmed per unit on your own test bench — the datasheet numbers match; the measurement that counts is yours.
How a second source gets qualified
- You send the part number — AD500-9, or the Hamamatsu 905 nm APD you use — with your annual quantity and bias conditions.
- We confirm the position in writing: functional match, what matches, what needs drawing verification.
- We ship two to five samples so you can measure responsivity, capacitance and gain curve on your own test bench.
- We quote production volume once your sign-off is in, and hold the agreed lead time.
Not sure which 905 nm configuration?
Peak power, package, beam divergence, drive conditions and temperature drift are the five decisions that pick the right 905 nm emitter. Our 905 nm selection guide walks through each one so you can narrow a 905 nm source — and its matching APD — down to the exact build your optics want.
Frequently asked
Is TO46-905APD pin-to-pin with the First Sensor AD500-9?
Functionally, with one mechanical caveat. Both parts are 905 nm avalanche photodiodes with a 500 µm active area and a 100–200 V breakdown range, so the optical and bias path is close. What pin-to-pin does not settle is the exact package — the AD500-9 ships in TO52, LCC6.1F and bare die, while LumeLiDAR ships the TO46 can — and the capacitance / gain curve, which are confirmed against your receiver front-end before you order, not assumed.
Why look for an alternative if the 905 nm APD is still sold?
Because it is single-sourced. The First Sensor AD500-9 and the equivalent Hamamatsu 905 nm APDs are active parts, not discontinued — so this is not an end-of-life story. The reason to qualify a second source is supply-risk diversification, price, and lead time, all of which matter once a 905 nm APD sits on a volume LiDAR or rangefinder production line.
What if my design uses a smaller active area?
The 500 µm part matches the AD500-9 geometry. If your design uses a smaller active area, LumeLiDAR also ships the TO46-905APD-230-1 at 230 µm, and a shielded variant for high-ambient-light outdoor use. The exact geometry and gain curve are confirmed on samples against your optics, not on the datasheet headline.
Do you stock the TO46-905APD series?
We ship two to five samples from stock so you can measure responsivity, capacitance and gain curve on your own bench before any production commitment. Send the part number, your annual quantity and your bias conditions.
Dual-sourcing a 905 nm APD? Start with samples.
Send the part number, annual quantity and bias conditions. We confirm the position, ship two to five units, and quote production once your bench says yes.