PHOTODIODE
Si photodiode with preamp
S8785 series
Large area photodiode integrated with op amp and TE-cooler
S8785 series is a thermoelectrically cooled Si photodiode with preamp developed for low-light-level detection. A large area photodiode, op amp,
TE-cooler and feedback resistor (10 GΩ) are integrated into a single package. A thermistor is also included in the same package for temperature
control so that the photodiode and I-V conversion circuit can be cooled for stable operation. S8785 series also features low noise and low NEP,
and is especially suitable for NOx detection.
Features
Applications
l Large active area size
l NOx detection
S8785/-01: 10 × 10 mm
l Low-light-level measurement
S8785-02 : φ15.6 mm (lens)
l UV to NIR Si photodiode optimized for precision photometry
l Compact hermetic package with sapphire window
l High precision FET input operational amplifier
l High gain: Rf=10 GΩ
l Low noise and NEP
l High cooling efficiency
S8785/-02: ∆T=50 ˚C
S8785-01 : ∆T=30 ˚C
l High stability with thermistor
S8785 series may be damaged by Electro Static Discharge, etc. Please see Precautions for use in the last page.
■ Absolute maximum ratings
Parameter
Supply voltage (preamp)
Reverse voltage (S8785-02, photodiode)
Operating temperature
Storage temperature
Operating temperature (photodiode)
TE-cooler allowable voltage *1
TE-cooler allowable current
Thermistor power dissipation
*1: Max ripple: 10 %
*2: S8785-01: 3.7 V
Symbol
Value
Vcc
±20 V
VR
30 V
Topr
-30 to +60 °C
Tstg
-40 to +80 °C
Tdopr -30 to +60 °C
Vte
5 V *2
Ite
1A
Pth
0.2 mW
■ Recommended operating conditions
Parameter
Symbol
Supply voltage (preamp)
Vcc
VR
Reverse voltage (photodiode)
TE-cooler current
Ite
Thermistor power dissipation Pth
Load resistance
RL
■ Electrical and optical characteristics (Typ. Vcc=±15 V, RL=1 M9)
Parameter
Symbol
Spectral response range
Peak sensitivity wavelength
Feedback resistance
l
lp
Rf
Photo sensitivity
S
Output noise voltage
Noise equivalent power
Output offset voltage
Cut-off frequency
Output voltage swing
Supply current
Thermistor resistance
Vn
NEP
Vos
fc
Vo
Icc
Rth
Condition
l=200 nm
l=lp
Dark state, f=10 Hz
l=lp, f=10 Hz
Dark state
-3 dB
Dark state
S8785
S8785-01
T= -25 °C
T= -5 °C
VR=0 V
VR=0 V
190 to 1100
960
10
-0.9
-0.9
-5.1
-5.1
20
25
4
5
±2
±2
190
180
-13
0.3
86
30
S8785/-01 S8785-02
±5 to ±15 V
0V
15 V
0.8 A Max.
0.03 mW Max.
100 kW Min.
S8785-02
T= -25 °C
VR=15 V
320 to 1100
-6.5
12
2
±3
170
86
Unit
nm
nm
GW
V/nW
µVrms/Hz1/2
fW/Hz1/2
mV
Hz
V
mA
kW
1
Si photodiode with preamp
■ Spectral response
-8
■ Frequency response
(Typ. Vcc=±15 V, S8785/-01: VR=0 V, S8785-02: VR=15 V)
10
(Typ. Vcc=±15 V, S8785/-01: VR=0 V, S8785-02: VR=15 V)
S8785
(T= -25 ˚C)
-7
RELATIVE OUTPUT (dB)
S8785-02 (T= -25 ˚C)
PHOTO SENSITIVITY (V/nW)
S8785 series
-6
-5
-4
-3
S8785 (T= -25 ˚C)
S8785-01 (T= -5 ˚C)
-2
0
S8785-02
(T= -25 ˚C)
-10
-20
S8785-01
(T= -5 ˚C)
-30
10
100
-1
0
200
400
600
800
1000
WAVELENGTH (nm)
1000
10000
FREQUENCY (Hz)
KSPDB0205EA
KSPDB0206EA
■ NEP vs. frequency
(Typ. Vcc=±15 V, S8785/-01: VR=0 V, S8785-02: VR=15 V)
10-3
OUTPUT NOISE VOLTAGE (Vrms/Hz1/2)
10-12
■ Output noise voltage vs. frequency
NEP (fWrms/Hz1/2)
S8785-01
(T= -5 ˚C)
10-13
S8785
(T= -25 ˚C)
10-14
S8785-02 (T= -25 ˚C)
10
-15
(Typ. Vcc=±15 V, S8785/-01: VR=0 V, S8785-02: VR=15 V)
S8785-01
(T= -5 ˚C)
10-4
S8785
(T= -25 ˚C)
-5
10
S8785-02 (T= -25 ˚C)
-6
10
-7
1
10
100
1000
10
10000
1
10
FREQUENCY (Hz)
100
1000
10000
FREQUENCY (Hz)
KSPDB0207EA
KSPDB0208EA
■ Detector temperature vs. TE-cooler current
6
Vte vs. Ite
4
10
T vs. Ite
0
3
-10
2
-20
1
-30
0
0.2
0.4
0.6
0.8
0
1.0
TE-COOLER CURRENT Ite (A)
6
5
20
T vs. Ite
10
4
Vte vs. Ite
0
3
-10
2
-20
1
-30
0
0.2
0.4
0.6
0.8
0
1.0
TE-COOLER CURRENT Ite (A)
KSPDB0151EB
2
DETECTOR TEMPERATURE T (˚C)
5
20
(Typ. Ta=25 ˚C)
30
TE-COOLER VOLTAGE Vte (V)
30
DETECTOR TEMPERATURE T (˚C)
S8785-01
(Typ. Ta=25 ˚C)
TE-COOLER VOLTAGE Vte (V)
S8785/-02
KSPDB0172EB
Si photodiode with preamp
S8785 series
■ External connection
S8785/-01
TE-COOLER
+
Vcc +
PACKAGE
THERMISTOR
Rf=10 GΩ
TE-COOLER
S8785: TWO-STAGE
S8785-01: ONE-STAGE
OUT
PHOTODIODE
+
GND
CASE
Vcc-
NC
KSPDC0044EA
S8785-02
TE-COOLER
+
Vcc +
PACKAGE
THERMISTOR
Rf=10 GΩ
TWO-STAGE
TE-COOLER
OUT
PHOTODIODE
+
Vcc-
VR
CASE
GND
NC
KSPDC0045EA
■ Thermistor resistance vs. temperature
■ Dimensional outlines (unit: mm)
S8785
(Typ.)
120
34.0 ± 0.2
80
WINDOW
16.0 ± 0.2
24.3 ± 0.2
ACTIVE AREA
4
27.4 ± 0.3
(2 ×)
60
13.5 ± 0.3
40
20
SAPPHIRE WINDOW (t=0.5)
10
20
30
PHOTOSENSITIVE
SURFACE
TEMPERATURE (˚C)
19 ± 1
0
6.0
-10
0.9 ± 0.2
-20
7.6 ± 0.3
0
-30
17.8 ± 0.3
THERMISTOR RESISTANCE (kΩ)
42.0 ± 0.4
100
KSPDB0152EA
INDEX MARK
KSPDA0071EB
3
Si photodiode with preamp
S8785-02
S8785-01
42.0 ± 0.4
42.0 ± 0.4
34.0 ± 0.2
34.0 ± 0.2
24.3 ± 0.2
ACTIVE AREA
24.3 ± 0.2
WINDOW
16.0 ± 0.2
16.0 ± 0.2
4
(2 ×)
4
7.0 ± 0.3
27.4 ± 0.3
27.4 ± 0.3
(2 ×)
S8785 series
SAPPHIRE WINDOW (t=0.5)
15.6
13.5 ± 0.3 7.2
7.6 ± 0.3
INDEX MARK
KSPDA0079EA
7.6 ± 0.3
17.8 ± 0.3
17.8 ± 0.3
7.6 ± 0.3
INDEX MARK
1.0 ± 0.2
17.8 ± 0.3
(12 ×)
19 ± 1
0.9 ± 0.2
19 ± 1
(4.7)
PHOTOSENSITIVE
SURFACE
0.9 ± 0.2
PLASTIC LENS
A tantalum or ceramic capacitor of 0.1 to 10 µF must be connected to the supply voltage leads
(pins ➃ and ➉) as a bypass capacitor used to prevent the device from oscillation.
KSPDA0088EB
Precautions for use
■ ESD
S8785 series may be damaged or their performance may deteriorate by such factors as electro static discharge from the
human body, surge voltage from measurement equipment, leakage voltages from soldering irons and packing materials. As a
countermeasure against electro static discharge, the device, operator, work place and measuring jigs must all be set at the
same potential. The following precautions must be observed during use:
•To protect the device from electro static discharge which accumulate on the operator or the operator,s clothes, use a wrist
,
strap or similar tools to ground the operator s body via a high impedance resistor (1 MΩ).
•A semiconductive sheet (1 MΩ to 10 MΩ) should be laid on both the work table and the floor in the work area.
•When soldering, use an electrically grounded soldering iron with an isolation resistance of more than 10 MΩ.
•For containers and packing, use of a conductive material or aluminum foil is effective. When using an antistatic material, use
one with a resistance of 0.1 MΩ/cm2 to 1 GΩ/cm2.
■ Strength
Thermoelectrically-cooled devices may be damaged if subjected to shock, for example drop impact. Take sufficient care
when handling these devices.
■ Lead forming
When forming the leads, take care not to apply excessive force to the lead sealing glass. Excessive force may impair the
hermetic sealing, possibly degrading the cooling capacity.
To form the leads, hold the roots of the leads securely with a pair of pliers and bend them.
■ Heatsink
Use a heatsink with thermal resistance less than 1.3 °C/W. Apply thermal grease between the heatsink and detector
package, and then fasten them with the screws. Be careful not to give any excessive force or mechanical stress to the
detector package at this point.
■ Wiring
• Be careful not to misconnect the plus and minus leads of the thermoelectric cooler or preamplifier. Supplying a voltage or
current while these connections are reversed may damage the device.
• The feedback resistor integrated into S8785 series is high so it is susceptible to external noise. Always ground the case
terminal when using S8785.
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. ©2003 Hamamatsu Photonics K.K.
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: Smidesvägen 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
4
Cat. No. KSPD1055E03
Jan. 2003 DN