DATA SHEET APD50
APD AVALANCHE PHOTODIODE PREAMPLIFIER
A Si avalanche photodiode and low noise preamplifier module. A field effect transistor input stage
ensures low HF noise and wide bandwidth. The bias voltage supply has temperature compensation to
maintain the APD. gain constant.
Preferred detector sizes are dia. 0.5 and 2.5 mm. Alternately a
0.5 mm version with lensed cap magnifies the detector (to
~2 mm for beams converging less than 0.1 N.A.). For other
detector diameters — 0.25 to 5 mm in TO52 case, or 0.8 to
2.5 mm in TO5 case, please ask for details.
The gain of an APD is temperature sensitive (around –4%/C at gain of 100). A nominal temperature correction
is applied to the bias voltage to reduce this to less than ±1%/C. Improved correction can be done at extra cost,
or the customer can optimize this himself - e.g. if using a different gain. A procedure for setting gain and
temperature correction back to the original values is described in the handbook (all of this assumes a
competent person using anti-static precautions).
Because APDs use high voltages, there may be self heating if >uW intensities are continuously present. The
bias supply is designed to shut down under these conditions.
ver 061404
5700 Corsa Avenue, #105 • Westlake Village, CA 91362
Tel: (818) 706-3400 • Fax (818) 889-7053
Email: sales@pacific-sensor.com • www.pacific-sensor.com
Page 1 of 3
Ostendstr 1, D-12459 Berlin, Germany
Tel: +49 (0) 30-53510 34 • Fax: +49 (0) 30-53790 262
Email: sales@silicon-sensor.de
United Kingdom
Email: pnsilsensuk@btinternet.com
• D.c. to 25 MHz (10 MHz for large detector).
• Fully DC-coupled with good pulse response.
• Various detector sizes are available.
• 50 Ω output for driving long cables.
• The APD50 is fully DC-coupled with dark offset <1 mV
and good DC stability for detecting low level signals.
Dimensions
Length
80
Width
56
Height
28
Overall Length
92
Weight
150g
The amplifier comes with 1.5 metre supply lead and requires ±15V <100mA.
Specifications (At 22°C into 50 Ω load)
Gain at 800 nm
Bandwidth
Risetime <10% overshoot
Dark noise (NSD)
0.5 mm Detector
2.5 x 106 V/W
25 MHz
14 ns
30 fW/√Hz
2.5 mm Detector
1.25 x 106 V/W
15 MHz
23 ns
300 fW/√Hz
DATA SHEET APD50
APD AVALANCHE PHOTODIODE PREAMPLIFIER
ver 061404
5700 Corsa Avenue, #105 • Westlake Village, CA 91362
Tel: (818) 706-3400 • Fax (818) 889-7053
Email: sales@pacific-sensor.com • www.pacific-sensor.com
Page 3 of 3
Ostendstr 1, D-12459 Berlin, Germany
Tel: +49 (0) 30-53510 34 • Fax: +49 (0) 30-53790 262
Email: sales@silicon-sensor.de
United Kingdom
Email: pnsilsensuk@btinternet.com
Noise Considerations for APD50
Case Outline Drawing for APD50
BNC O/P
POWER
APD
80.0 mm
25.4 mm
28.4 mm
53.6 mm 16.0 mm
20.0 mm
DATA SHEET APD50
APD AVALANCHE PHOTODIODE PREAMPLIFIER
ver 061404
5700 Corsa Avenue, #105 • Westlake Village, CA 91362
Tel: (818) 706-3400 • Fax (818) 889-7053
Email: sales@pacific-sensor.com • www.pacific-sensor.com
Page 2 of 3
Ostendstr 1, D-12459 Berlin, Germany
Tel: +49 (0) 30-53510 34 • Fax: +49 (0) 30-53790 262
Email: sales@silicon-sensor.de
United Kingdom
Email: pnsilsensuk@btinternet.com
Noise Considerations for APD50
Noise Considerations for APD50
Small - 0.5 Detector with ~30 MHz b/w, at 800 nm.
Large - 2.5 dia Detector with ~10 MHz b/w, at 800 nm.
The graphs below show how noise performance is affected by APD gain. They are computed curves for
guidance only. Curves are noise spectral density in W/Hz-1/2 (the lower the curve, the better the signal-to-noise
ration). Lower curves (with circles) are dark noise. Upper curves (with boxes) are NSD at full bandwidth.
Modules normally have gain set to 100 for small and 50 for large detectors. Gain adjustments is possible and is
explained in the handbook.
10 pW.Hz–1/2
1 pW.Hz–1/2
NSD
APD Gain
100 fW.Hz–1/2
10 fW.Hz–1/2
1 uW
100 nW
10 nW
Light Power
1 nW
100 pW Dark
1 uW
100 nW
Light Power
10 pW Dark
1 10 100 1000
10 pW.Hz–1/2
1 pW.Hz–1/2
NSD
APD Gain
100 fW.Hz–1/2
1 10 100 1000
