C4674 Datasheet, PDF (2/3 Pages) Hamamatsu Corporation – Signal processing circuit for 2-D PSD

Signal processing circuit for 2-D PSD C4674, C4757, C4758, C7563
s Absolute maximum ratings
Parameter
Signal
processor
LED driver
Supply voltage
Input current
Output short-circuit time
Operating temperature
Transistor collector-emitter voltage
Transistor collector current *³
Transistor collector dissipation *³
DC circuit
AC circuit
Symbol _{C4674 C4757}
C4758
C7563
Unit
Vcc Max.
±18
V
IIN Max.
Vcc Max. × 10^-5
A
-
Continuous
s
Topr
0 to +50
°C
VCE
-
-
-
+50
V
IC
-
-
-
2
A
Pc
-
-
-
900
mW
s Specifications (Ta=25 °C, Vcc=±15 V)
Typical value
Parameter
Symbol
Condition
DC circuit
AC circuit
Unit
C4674 C4757 C4758
C7563
Head-amp conversion impedance *⁴ Rf Factory setup prior to shipping
1 × 10⁵
V/A
Feedback capacitance
Cf Factory setup prior to shipping
100
22
pF
Input signal current *⁵
IIN
Photocurrent with PSD
installed
1 × 10^-5 to 1 × 10^-4
A
Output response time
Rise time
tr
versus movement of light
spot position, measured
30
µs
Signal
with PSD installed.
processor _{PSD reverse bias voltage VR -}
+5
V
Output offset voltage
VOS *⁷
-10 to +10
mV
With PSD installed and
O utput voltage a m plitude *⁶ Vo light spot falling on edge
-10 to +10
V
of active area.
Output noise (analog divider) Vn All range *⁷
5
10
mVp-p
Current consumption
Icc *⁷
±15
±60
mA
Transistor collector current
Ic *³
-
-
-
680
mAp-p
LED Repetition frequency
fT *⁸
-
-
-
333
Hz
driver
Output type
--
-
-
-
Open
collector
-
*3: Duty ratio: 3/100, pulse width: 90 µs, LED: Hamamatsu L1915-01 (sold separately)
*4: These resistors are lead types and inserted into sockets, so it can be easily to exchange by the user if necessary in a range
between 1 × 10⁴ to 1 × 10⁶ Ω. For more details, see the instruction manual that comes with the product.
*5: The circuit does not operate correctly when input signal level is not appropriate.
*6: Maximum output amplitude can be adjusted in a range of ±2 to ±10 V according to PSD type to be used.
*7: Measured without PSD and with LED turned off, while using a current source of 20 µA (X1=X2=Y1=Y2) substituting for PSD
photocurrent. In the case of C7563, however, pulse current with a duty ratio of 3/100 and a pulse width of 90 µs is supplied.
*8: Repetition frequency 333 Hz (duty ratio: 3/100, pulse width: 90 µs) cannot be modulated.
s Operating example (C4674)
+V +15 V
2-D
PSD
Y2
SIGNAL
3
X2
PROCESSING CIRCUIT
5
4
VR
C4674
1
2
Y1
X1
GND _{0 V REGULATED}
POWER
-V _{-15 V SUPPLY *}
Xout
GND
+
- ^VOLTMETER
Yout
+
GND
- VOLTMETER
Constant voltage power supply: ±15 V, Power capacity: 0.1 A Min.
Ripple voltage: 3 mVp-p Max.
KPSDC0034ED
Condition
1. Light source
2. Light spot diameter
LED (λ=900 nm)
φ200 µm
The followings are obtained with the conditions listed
on the left.
3. PSD used
S1880 (12 × 12 mm)
4. PSD photocurrent
5. Signal processing circuit
6. Frequency bandwidth
7. Voltmeter
10 µA
C4674
10 Hz
KEITHLEY model 195 A
Output voltage amplitude
Position resolution
(calculated values)
VFS (X)=±6 V
VFS (Y)=±6 V
∆x=0.1 µm approx.
∆y=0.1 µm approx.
2