Signal processing circuit for 2-D PSD
s
Absolute maximum ratings
Parameter
Supply voltage
Input current
Output short-circuit time
Operating temperature
Transistor collector-emitter voltage
Tra n sist or collector current *
3
Tra n sist or collector dissipatio n *
3
C4674, C4757, C4758, C7563
Symbol
Vcc Max.
I
IN
Max.
-
Topr
V
CE
I
C
Pc
DC circuit
C4757
C4758
±18
Vcc Max. × 10
-5
Continuous
0 to +50
-
-
-
-
-
-
A C circuit
C7563
Unit
V
A
s
°C
V
A
mW
C4674
Signal
processor
LED driver
-
-
-
+50
2
900
s
Specifications (Ta=25
°C,
Vcc=
±
15 V)
Parameter
Head-amp conversion impedance *
4
Feedback capacitance
Input signal current *
5
Sy mbol
Rf
Cf
I
IN
Condition
C4674
Factory setup prior to shipping
Factory setup prior to shipping
Photocurrent with PSD
installed
O utput resp ons e tim e
versus m ov e m e nt of lig ht
spot position, me asured
with P S D installed.
-
*
7
With PSD installed and
light spot falling on edge
of active area.
All ran g e *
7
*
7
*
3
*
8
-
Typical value
DC circuit
C4757
C4758
1 × 10
5
100
1 × 10
-5
to 1 × 10
-4
AC circuit
C7563
22
Unit
V/A
pF
A
Rise time
Signal
processor
PSD reverse bias voltage
Output offset voltage
O utput voltage a m plitude *
6
O utput noise (analog divider)
Current consumption
Transistor collector curre nt
Repetition frequency
Output type
tr
V
R
V
OS
Vo
Vn
Icc
Ic
f
T
-
30
+5
-10 to +10
-10 to +10
5
±15
-
-
-
10
±60
680
333
Open
collector
µs
V
mV
V
mVp-p
mA
mAp-p
Hz
-
LED
driver
-
-
-
-
-
-
*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 × 10
4
to 1 × 10
6
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
GND
-V
+15 V
0 V REGULATED
POWER
-15 V SUPPLY *
+
- VOLTMETER
+
- VOLTMETER
2-D
PSD
Y
2
X
2
V
R
Y
1
X
1
SIGNAL
PROCESSING CIRCUIT
C4674
3
5
4
1
2
Xout
GND
Yout
GND
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
3. PSD used
4. PSD photocurrent
5. Signal processing circuit
6. Frequency bandwidth
7. Voltmeter
LED (λ=900 nm)
φ200
µm
S1880 (12 × 12 mm)
10 µA
C4674
10 Hz
KEITHLEY model 195 A
The followings are obtained with the conditions listed
on the left.
Output voltage amplitude
Position resolution
(calculated values)
V
FS
(X)=±6 V
V
FS
(Y)=±6 V
∆x=0.1
µm approx.
∆y=0.1
µm approx.
2
HAMAMATSU [ HAMAMATSU CORPORATION ]
