A P D
PRELIMINARY DATA
Jan. 2001
S8328
S8328 is a quadrant APD (Avalanche Photodiode) having a gain of 2-100. The peak gain lies at 420 nm and creates a high
sensitivity for blue to violet minor signals. An on-chip bias control circuit gives the most stable output from low to high temperature.
S8328 provides the improved detection on the basis of gain and S/N restoration.
Si APD
Quadrant APD with high bluish-violet sensitivity
Features
l Level up the low S/N for minor bluish-violet signals
l Level up the dropped S/N due to a noisy preamplifier
l A wide range of practical gain
l Uniform gain and sensitivity in area
l High-speed response
l Low dark current
l Low excess noise
l Output independency to temperature under its bias control IC
Applications
l Optical pick-up for bluish-violet LD
l Ultra high density optical memories
US Patent Pending
n Absolute maximum ratings
n Recommended operating conditions (Ta=25 C)
n Electrical and optical characteristics (Ta=25 C, per element)
Vk
-0.6 to V
BR
*
1
(Breakdown voltage)
V
Vcc
6.0
V
Topr
-20 to +80
C
Tstg
-40 to +100
C
*1: Ta=25 C, Ik=1
A
Min.
Typ.
Max.
Vk
Vsp *
2
V
BR
- 10
V
BR
- 1.5
V
Vcc
4.75
5.0
5.25
V
*2: Interchannel resistance Rch=100 M
The output from a quadrant APD is not divided by each element if lower than Vsp.
Min.
Typ.
Max.
-
390 to 800
-
nm
p
-
540
-
nm
=420 nm, V
BR
- 10
1.0
1.5
-
A/W
S
=650 nm, V
BR
- 10
1.2
1.8
-
A/W
M
=420 nm, V
BR
- 10
-
10
-
-
M
=420 nm, VkV
BR
-1.5
2
-
100
-
V
BR
Ik=1
A, dark state
-
-
90
-
V/ C
V
BR
*
3
= V
BR
+
(T *
5
- 25)
-
0.075
-
Vsp
-
45
65
V
V
Rp
=420 nm, V
BR
- 10
-
-
5
%
Ct
Vk=80 V, f=1 MHz
-
-
pF
fc
Vk=80 V, R
L
=50
=830 nm, -3 dB
-
0.9
-
GHz
I
D
V
BR
- 10
-
-
0.5
nA
x
=420 nm, M=100
f=100 kHz, I
L
=20 nA
-
0.4
-
Value
Unit
Unit
Unit
Parameter
Symbol
Parameter
Symbol
Condition
Parameter
Symbol
APD cathode voltage
Supply voltage (bias control IC)
Operating temperature
Storage temperature
APD cathode voltage range
Supply voltage range
Spectral response range
Peak sensitivity wavelength
Photo sensitivity
Gain
Practical gain
Breakdown voltage
Temperature coefficient of V
BR
Channel separation cathode voltage
Sensitivity difference between element
Terminal capacitance
Cut-off frequency
Dark current
Excess noise index
7 *
4
-
Vcc=5 V
Icc
0.9
1.5
mA
Dissipation current
*3: Breakdown voltage at temperature T
*4: Total value of all elements
*5: T: APD temperature
-
Io/T *
5
=420 nm, V
BR
- 10
15 C, I
L
=20 nA
1
4
%
Temperature dependence of
output stability
Si APD
S8328
0
20
15
10
5
200
300
400
500
600
700
800
900
(Typ. Ta=25 C)
1000
WAVELENGTH (nm)
PHOTO SENSITIVITY (A/W)
Vk = V
BR
- 10
Vk = V
BR
- 4
Vk = V
BR
- 2
POSITION ON A
CTIVE AREA
(
m)
POSITION ON A
CTIVE AREA (
m)
RELA
TIVE OUTPUT (%)
0
10
0
100
200
300
(Vk=V
BR
- 10)
100
0
300
200
20
30
40
50
60
70
80
90
100
s Spectral response
KAPDB0038EA
s Spatial sensitivity image
KAPDB0039EA
0
70
60
50
40
30
20
10
200
300
400
500
600
700
800
900
(Typ. Ta=25 C)
1000
WAVELENGTH (nm)
GAIN
Vk = V
BR
- 4
Vk = V
BR
- 2
Vk = V
BR
- 10
s Gain vs. wavelength
KAPDB0042EA
0.1
10000
1000
100
10
1
-35
-30
-25
-20
-15
-10
-5
(Typ. Ta=25 C,
=420 nm)
0
CATHODE VOLTAGE - BREKDOWN VOLTAGE (V)
PHOTO SENSITIVITY (A/W)
0
1.5
1
0.5
0
10
20
30
40
50
60
70
80
90
TEMPERATURE (C)
PHOTOCURRENT (A)
M20 (Vk = V
BR
- 6)
WITH IC BIAS CONTROL
M20 (Vk = V
BR
- 6) APD ALONE
(
l=465 nm)
M10 (Vk = V
BR
- 10) APD ALONE
M10 (Vk = V
BR
- 10)
WITH IC BIAS CONTROL
s Photo sensitivity vs. cathode voltage
KAPDB0040EA
s Temperature characteristics
KAPDB0041EA
0
0.5
0.4
0.3
0.2
0.1
1
10
100
1000
(Typ. Ta=25 C,
=465 nm)
10000
GAIN
EXCESS NOISE INDEX
I
L
=2 nA
I
L
=20 nA
Vn
2
=2qI
L
M
(2+x)
BR
2
Vn: Noise voltage (V/Hz
1/2
)
I
L
: Photocurrent at M=1 (A)
x
: Excess noise index
B : Bandwidth (Hz)
s Excess noise index vs. gain
KAPDB0043EA
Si APD
S8328
On-chip IC's auto bias control over a wide range of temperature
An APD gain is subject to the temperature dependence. To keep the unchanged output from low to high temperature, it requires
a precise and tiresome adjustment for the variable breakdown voltage. S8328 incorporates bias controlled circuits including
thermo-sensor to give its automatic adjustment allowing a minimum influence of temperature to the APD gain.
A typical bias control configuration is shown above. The APD gain is set by the resistance connected to the Rex terminal (pin 4).
A few additional components are required to compose the whole circuits.
(1) The configuration above is an example used with 4-channel trans-impedance amplifiers (TIA). In case of using op amp, its
offset voltage and the reference voltage (Vref) should be the least dependent to temperature.
(2) The resistance connected to the Rex terminal is to be a temperature coefficient of 100 ppm/C or less.
Note)
Hamamatsu could also provide a sample of external connection circuit (with booster circuit, but TIA not included) that allows you
to examine a bias control circuit.
The external connection circuit components listed in this material are typical parts that can be used to configure a bias circuit, but
we do not guarantee their complete reliability. If high reliability and safety are required to obtain adequate functions and accuracy
from the bias circuit, please run the necessary reliability tests to ensure a safe design for the system and the entire equipment.
CATHODE
VOLTAGE
FEEDBACK
RESISTANCE
TO EACH
ELEMENT
REF.
CURRENT
THERMO-
SENSOR
ERROR
AMP
QUADRANT
APD
d
VT
Rex
V+
Vkr
Vcc
GND
Err
Vk
c
b
a
+
-
GND
Vcc
VT
Rex
d
c
b
a
Err
V+
Vk
Vkr
Thermosensor output monitor
APD gain setting resistance
APD anode
APD anode
APD anode
APD anode
Error amp output
Feedback voltage monitor
APD cathode (Connected to 4 ch.)
Cathode voltage input
NOTE) Use pins to and
when connecting the APD alone.
Pin No. Symbol
+5 V
Function
s Equivalent circuit
KAPDC0008EA
s Typical bias control circuit
KAPDC0008EA
10 k
W
5 V
120 10 V
22 k
W
Tr: 2SC3138-Y (or equivalent)
200 k
W
10 k
W
100 k
W
3.3 k
W
Vref
0.1
mF
0.47
mF/200 V
0.47
mF/200 V
OUTPUT A
OUTPUT B
OUTPUT C
OUTPUT D
-
+
-
+
-
+
-
+
0.001
mF
0.1
mF
Si APD
S8328
HAMAMATSU PHOTONICS K.K., Solid State Division
1126-1 Ichino-cho, Hamamatsu City, 435-8558 Japan, Telephone: (81) 053-434-3311, Fax: (81) 053-434-5184, http://www.hamamatsu.com
U.S.A.: Hamamatsu Corporation: 360 Foothill Road, P.O.Box 6910, Bridgewater, N.J. 08807-0910, U.S.A., Telephone: (1) 908-231-0960, Fax: (1) 908-231-1218
Germany: Hamamatsu Photonics Deutschland GmbH: Arzbergerstr. 10, D-82211 Herrsching am Ammersee, Germany, Telephone: (49) 08152-3750, Fax: (49) 08152-2658
France: Hamamatsu Photonics France S.A.R.L.: 8, Rue du Saule Trapu, Parc du Moulin de Massy, 91882 Massy Cedex, France, Telephone: 33-(1) 69 53 71 00, Fax: 33-(1) 69 53 71 10
United Kingdom: Hamamatsu Photonics UK Limited: 2 Howard Court, 10 Tewin Road, Welwyn Garden City, Hertfordshire AL7 1BW, United Kingdom, Telephone: (44) 1707-294888, Fax: (44) 1707-325777
North Europe: Hamamatsu Photonics Norden AB: Smidesvgen 12, SE-171 41 Solna, Sweden, Telephone: (46) 8-509-031-00, Fax: (46) 8-509-031-01
Italy: Hamamatsu Photonics Italia S.R.L.: Strada della Moia, 1/E, 20020 Arese, (Milano), Italy, Telephone: (39) 02-935-81-733, Fax: (39) 02-935-81-741
Information furnished by HAMAMATSU is believed to be reliable. However, no responsibility is assumed for possible inaccuracies or omissions.
Specifications are subject to change without notice. No patent rights are granted to any of the circuits described herein. 2001 Hamamatsu Photonics K.K.
Cat. No. KAPD1006E01
Jan. 2001 DN
a
b
d
c
0.3 mm
4.6 0.2
(INCLUDING BURR)
0.4
0.3
0.8
0.8
0.8
0.8
0.8
4.5
1.5 0.4
1.5 0.4
5.6 0.2
(INCLUDING BURR)
5.4
10
5.5
0.7
1.0
2.0
7.5 0.3
0.7 0.3
0.7 0.3
5
0.25
0.1 0.1
3
3
PHOTOSENSITIVE
SURFACE
GND
Vcc
VT
Rex
d
c
b
a
Err
V+
Vk
Vkr
INDEX MARK
KAPDA0019EA
s Dimensional outline (unit: mm)
s Cross section of element
GND
Vcc
VT Rex
a
d
N
(APD)
P
P
P
c
b
Vk
Vkr
V+
Err
(IC)
(IC)
KAPDA0010EA
PDF 
ZIP