BB OPT301

®
OPT301
FPO
70%
INTEGRATED PHOTODIODE
AND AMPLIFIER
FEATURES
DESCRIPTION
● PHOTODIODE SIZE: 0.090 x 0.090 inch
(2.29 x 2.29mm)
The OPT301 is an opto-electronic integrated circuit
containing a photodiode and transimpedance
amplifier on a single dielectrically isolated chip. The
transimpedance amplifier consists of a precision FETinput op amp and an on-chip metal film resistor. The
0.09 x 0.09 inch photodiode is operated at zero bias for
excellent linearity and low dark current.
● 1MΩ FEEDBACK RESISTOR
● HIGH RESPONSIVITY: 0.47A/W (650nm)
● IMPROVED UV RESPONSE
● LOW DARK ERRORS: 2mV
● BANDWIDTH: 4kHz
● WIDE SUPPLY RANGE: ±2.25 to ±18V
The integrated combination of photodiode and
transimpedance amplifier on a single chip eliminates
the problems commonly encountered in discrete designs such as leakage current errors, noise pick-up and
gain peaking due to stray capacitance.
● LOW QUIESCENT CURRENT: 400µA
● HERMETIC TO-99
The OPT301 operates over a wide supply range (±2.25
to ±18V) and supply current is only 400µA. It is
packaged in a hermetic TO-99 metal package with a
glass window, and is specified for the –40°C to 85°C
temperature range.
APPLICATIONS
● MEDICAL INSTRUMENTATION
● LABORATORY INSTRUMENTATION
● POSITION AND PROXIMITY SENSORS
● PHOTOGRAPHIC ANALYZERS
● SMOKE DETECTORS
40pF
75Ω
λ
5
VO
Infrared
0.5
Using Internal
1MΩ Resistor
0.4
0.4
0.3
0.3
0.2
0.2
0.1
0.1
Photodiode Responsivity (A/W)
4
Voltage Output (V/µW)
1MΩ
Red
Blue
Ultraviolet
0.5
2
Green
Yellow
SPECTRAL RESPONSIVITY
OPT301
8
1
V+
0
3
100
V–
200 300 400 500
600
0
700 800 900 1000 1100
Wavelength (nm)
International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111
Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
©
1994 Burr-Brown Corporation
PDS-1228B
Printed in U.S.A. January, 1994
SPECIFICATIONS
ELECTRICAL
At TA = +25°C, VS = ±15V, λ = 650nm, internal 1MΩ feedback resistor, unless otherwise noted.
OPT301M
PARAMETER
CONDITIONS
RESPONSIVITY
Photodiode Current
Voltage Output
vs Temperature
Unit-to-Unit Variation
Nonlinearity(1)
Photodiode Area
DARK ERRORS, RTO(2)
Offset Voltage, Output
vs Temperature
vs Power Supply
Voltage Noise
MIN
650nm
650nm
650nm
FS Output = 10V
(0.090 x 0.090in)
(2.29 x 2.29mm)
0.47
0.47
200
±5
0.01
0.008
5.2
VS = ±2.25V to ±18V
Measured BW = 0.1 to 100kHz
±0.5
±10
10
160
RESISTOR—1MΩ Internal
Resistance
Tolerance
vs Temperature
FREQUENCY RESPONSE
Bandwidth, Large or Small-Signal, –3dB
Rise Time, 10% to 90%
Settling Time, 1%
0.1%
0.01%
Overload Recovery Time
OUTPUT
Voltage Output
1
±0.5
50
FS to Dark
FS to Dark
FS to Dark
100% overdrive, VS = ±15V
100% overdrive, VS = ±5V
100% overdrive, VS = ±2.25V
RL = 10kΩ
RL = 5kΩ
(V+) – 1.25
(V+) – 2
Capacitive Load, Stable Operation
Short-Circuit Current
POWER SUPPLY
Specified Operating Voltage
Operating Voltage Range
Quiescent Current
TYP
±2.25
IO = 0
TEMPERATURE RANGE
Specification
Operating/Storage
Thermal Resistance, θJA
MAX
UNITS
A/W
V/µW
ppm/°C
%
% of FS
in2
mm2
±2
100
±2
mV
µV/°C
µV/V
µVrms
MΩ
%
ppm/°C
4
90
240
350
900
240
500
1000
kHz
µs
µs
µs
µs
µs
µs
µs
(V+) – 0.65
(V+) – 1
10
±18
V
V
nF
mA
±15
±0.4
–40
–55
±18
±0.5
V
V
mA
+85
+125
°C
°C
°C/W
MAX
UNITS
200
NOTES: (1) Deviation in percent of full scale from best-fit straight line. (2) Referred to Output. Includes all error sources.
PHOTODIODE SPECIFICATIONS
At TA = +25°C, unless otherwise noted.
Photodiode of OPT301
PARAMETER
CONDITIONS
Photodiode Area
Current Responsivity
Dark Current
vs Temperature
Capacitance
MIN
(0.090 x 0.090in)
(2.29 x 2.29mm)
650nm
VD = 0V(1)
VD = 0V(1)
NOTE: (1) Voltage Across Photodiode.
®
OPT301
TYP
0.008
5.1
0.47
500
doubles every 10°C
4000
2
in2
mm2
A/W
fA
pF
SPECIFICATIONS
(CONT)
Op Amp Section of OPT301(1)
ELECTRICAL
At TA = +25°C, VS = ±15V, unless otherwise noted.
OPT301 Op Amp
PARAMETER
INPUT
Offset Voltage
vs Temperature
vs Power Supply
Input Bias Current
vs Temperature
CONDITIONS
MIN
TYP
MAX
UNITS
±0.5
±5
10
1
doubles every 10°C
mV
µV/°C
µV/V
pA
30
25
15
0.8
nV/√Hz
nV/√Hz
nV/√Hz
fA/√Hz
INPUT VOLTAGE RANGE
Common-Mode Input Range
Common-Mode Rejection
±14.4
106
V
dB
INPUT IMPEDANCE
Differential
Common-Mode
1012||3
1012||3
Ω||pF
Ω||pF
OPEN-LOOP GAIN
Open-Loop Voltage Gain
120
dB
FREQUENCY RESPONSE
Gain-Bandwidth Product
Slew Rate
Settling Time 0.1%
0.01%
380
0.5
4
5
kHz
V/µs
µs
µs
(V+) – 0.65
(V+) – 1
±18
V
V
mA
VS = ±2.25V to ±18V
NOISE
Input Voltage Noise
Voltage Noise Density, f=10Hz
f=100Hz
f=1kHz
Current Noise Density, f=1kHz
OUTPUT
Voltage Output
6
RL = 10kΩ
RL = 5kΩ
(V+) – 1.25
(V+) – 2
Short-Circuit Current
POWER SUPPLY
Specified Operating Voltage
Operating Voltage Range
Quiescent Current
±2.25
IO = 0
±15
±0.4
±18
±0.5
V
V
mA
NOTE: (1) Op amp specifications provided for information and comparison only.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes
no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change
without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant
any BURR-BROWN product for use in life support devices and/or systems.
®
3
OPT301
PIN CONFIGURATION
ELECTROSTATIC
DISCHARGE SENSITIVITY
Top View
Common
This integrated circuit can be damaged by ESD. Burr-Brown
recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and
installation procedures can cause damage.
8
V+
1
7
–In 2
NC
Photodiode
Area
6 NC
3
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
5
V–
4
1MΩ Feedback
Output
NOTE: Metal package is internally connected to common (Pin 8).
PACKAGE INFORMATION
ABSOLUTE MAXIMUM RATINGS
Supply Voltage ................................................................................... ±18V
Input Voltage Range (Common Pin) .................................................... ±VS
Output Short-Circuit (to ground) ............................................... Continuous
Operating Temperature ................................................... –55°C to +125°C
Storage Temperature ...................................................... –55°C to +125°C
Junction Temperature .................................................................... +125°C
Lead Temperature (soldering, 10s) ................................................ +300°C
PACKAGE
PACKAGE DRAWING
NUMBER(1)
OPT301M
8-Pin TO-99
001-1
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix C of Burr-Brown IC Data Book.
®
OPT301
PRODUCT
4
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VS = ±15V, λ = 650nm, unless otherwise noted.
NORMALIZED SPECTRAL RESPONSIVITY
VOLTAGE RESPONSIVITY vs RADIANT POWER
10
(0.52A/W)
0.8
650nm
(0.47A/W)
Output Voltage (V)
Normalized Current or Voltage Output
1.0
0.6
0.4
Ω
M
1
RF
0.1
=
10
RF
=
Ω
1M
Ω
0k
RF
=
10
kΩ
0.01
RF
0.2
=
λ = 650nm
10
0.001
0
100
200 300 400 500
600
700 800 900 1000 1100
0.01
0.1
1
Wavelength (nm)
10
100
VOLTAGE OUTPUT RESPONSIVITY vs FREQUENCY
VOLTAGE RESPONSIVITY vs IRRADIANCE
10
10
RF = 10MΩ
λ = 650nm
RF = 3.3MΩ
1
Ω
Responsivity (V/µW)
Output Voltage (V)
1k
Radiant Power (µW)
M
RF
=
10
Ω
0.1
RF
=
1M
Ω
0k
RF
0.01
=
10
kΩ
RF
=
10
λ = 650nm
1
RF = 1MΩ
0.1
0.01
6
RF = 330kΩ CEXT = 30pF
RF = 100kΩ CEXT = 90pF
RF = 33kΩ CEXT = 180pF
RF = 10kΩ CEXT = 350pF
0.001
0.001
0.001
0.01
0.1
1
10
100
100
1k
Irradiance (W/m2)
1M
1.0
1.0
θ
50
40
Relative Response
λ = 650nm
Units (%)
100k
RESPONSE vs INCIDENT ANGLE
DISTRIBUTION OF RESPONSIVITY
60
Distribution Totals
100%
30
Laboratory Test
Data
20
10
0
0.45
10k
Frequency (Hz)
0.8
0.8
0.6
0.6
0.4
0.4
0.2
0.2
0
0.46
0.47
0.48
0.49
0
0.5
±20
±40
±60
0
±80
Incident Angle (°)
Responsivity (A/W)
®
5
OPT301
TYPICAL PERFORMANCE CURVES
At TA = +25°C, VS = ±15V, λ = 650nm, unless otherwise noted.
OUTPUT NOISE VOLTAGE
vs MEASUREMENT BANDWIDTH
QUIESCENT CURRENT vs TEMPERATURE
1000
0.6
Noise Voltage (µVrms)
VS = ±15V
0.4
0.3
VS = ±2.25V
Dice
0.2
Dotted lines show
noise beyond the
signal bandwidth.
100
Ω
MΩ
10
RF
=
0
10
MΩ
0
RF
=1
RF
=
1M
1
0.1
RF = 10kΩ CEXT = 350pF
RF = 100kΩ CEXT = 90pF
0.1
0
–75
–50
–25
0
25
50
75
100
1
125
10
100
1k
LARGE-SIGNAL DYNAMIC RESPONSE
SMALL-SIGNAL DYNAMIC RESPONSE
2V/div
100µs/div
100µs/div
NOISE EFFECTIVE POWER
vs MEASUREMENT BANDWIDTH
10–7
Dotted lines indicate
noise measured beyond
the signal bandwidth.
λ = 650nm
Noise Effective Power (W)
10–8
RF = 10k
RF = 100k
10–9
RF = 1M
10–10
RF = 10M
10–11
RF = 100M
10–12
10–13
10–14
1
10
100
1k
Measurement Bandwidth (Hz)
®
OPT301
10k
Measurement Bandwidth (Hz)
Temperature (°C)
20mV/div
Quiescent Current (mA)
0.5
6
10k
100k
100k
APPLICATIONS INFORMATION
If your light source is focused to a small area, be sure that
it is properly aimed to fall on the photodiode. If a narrowly
focused light source were to miss the photodiode area and
fall only on the op amp circuitry, the OPT301 would not
perform properly. The large (0.090 x 0.090 inch) photodiode
area allows easy positioning of narrowly focused light
sources. The photodiode area is easily visible—it appears
very dark compared to the surrounding active circuitry.
Figure 1 shows the basic connections required to operate the
OPT301. Applications with high-impedance power supplies
may require decoupling capacitors located close to the
device pins as shown. Output is zero volts with no light and
increases with increasing illumination.
The incident angle of the light source also affects the
apparent sensitivity in uniform irradiance. For small incident
angles, the loss in sensitivity is simply due to the smaller
effective light gathering area of the photodiode (proportional
to the cosine of the angle). At a greater incident angle, light
is reflected and scattered by the side of the package. These
effects are shown in the typical performance curve
“Response vs Incident Angle.”
2
1MΩ
ID is proportional
to light intensity
(radiant power).
λ
(0V)
RF
4
ID
40pF
75Ω
ID
5
VO
V O = I D RF
OPT301
8
NOTE: Metal package
is internally connected
to common (Pin 8).
1
DARK ERRORS
The dark errors in the specification table include all sources.
The dominant error source is the input offset voltage of the
op amp. Photodiode dark current and input bias current of
the op amp are approximately 2pA and contribute virtually
no offset error at room temperature. Dark current and input
bias current double for each 10°C above 25°C. At 70°C, the
error current can be approximately 100pA. This would
produce a 1mV offset with RF = 10MΩ. The OPT301 is
useful with feedback resistors of 100MΩ or greater at room
temperature. The dark output voltage can be trimmed to
zero with the optional circuit shown in Figure 3.
3
0.1µF 0.1µF
+15V
–15V
FIGURE 1. Basic Circuit Connections.
Photodiode current, ID, is proportional to the radiant power
or flux (in watts) falling on the photodiode. At a wavelength
of 650nm (visible red) the photodiode Responsivity, RI, is
approximately 0.45A/W. Responsivity at other wavelengths
is shown in the typical performance curve “Responsivity vs
Wavelength.”
6
CEXT
The typical performance curve “Output Voltage vs Radiant
Power” shows the response throughout a wide range of
radiant power. The response curve “Output Voltage vs
Irradiance” is based on the photodiode area of 5.23 x 10–6m2.
RF
2
The OPT301’s voltage output is the product of the photodiode
current times the feedback resistor, (IDRF). The internal
feedback resistor is laser trimmed to 1MΩ ±2%. Using this
resistor, the output voltage responsivity, RV, is approximately
0.45V/µW at 650nm wavelength.
1MΩ
4
40pF
75Ω
λ
An external resistor can be used to set a different voltage
responsivity. For values of RF less than 1MΩ, an external
capacitor, CEXT, should be connected in parallel with RF (see
Figure 2). This capacitor eliminates gain peaking and prevents
instability. The value of CEXT can be read from the table in
Figure 2.
5
VO = ID RF
OPT301
8
1
V+
LIGHT SOURCE POSITIONING
The OPT301 is 100% tested with a light source that uniformly
illuminates the full area of the integrated circuit, including
the op amp. Although all IC amplifiers are light-sensitive to
some degree, the OPT301 op amp circuitry is designed to
minimize this effect. Sensitive junctions are shielded with
metal, and differential stages are cross-coupled. Furthermore,
the photodiode area is very large relative to the op amp input
circuitry making these effects negligible.
3
V–
EXTERNAL RF
CEXT
100MΩ
10MΩ
1MΩ
330kΩ
100kΩ
33kΩ
10kΩ
(1)
(1)
(1)
30pF
130pF
180pF
350pF
NOTE: (1) No CEXT required.
FIGURE 2. Using External Feedback Resistor.
®
7
OPT301
approximately 0.02% up to 100µA photodiode current. The
photodiode can produce output currents of 1mA or greater
with high radiant power, but nonlinearity increases to several
percent in this region.
When used with very large feedback resistors, tiny leakage
currents on the circuit board can degrade the performance of
the OPT301. Careful circuit board design and clean assembly
procedures will help achieve best performance. A “guard
trace” on the circuit board can help minimize leakage to the
critical non-inverting input (pin 2). This guard ring should
encircle pin 2 and connect to Common, pin 8.
This excellent linearity at high radiant power assumes that
the full photodiode area is uniformly illuminated. If the light
source is focused to a small area of the photodiode,
nonlinearity will occur at lower radiant power.
DYNAMIC RESPONSE
Using the internal 1MΩ resistor, the dynamic response of
the photodiode/op amp combination can be modeled as a
simple R/C circuit with a –3dB cutoff frequency of 4kHz.
This yields a rise time of approximately 90µs (10% to 90%).
Dynamic response is not limited by op amp slew rate. This
is demonstrated by the dynamic response oscilloscope
photographs showing virtually identical large-signal and
small-signal response.
NOISE PERFORMANCE
Noise performance of the OPT301 is determined by the op
amp characteristics in conjunction with the feedback
components and photodiode capacitance. The typical
performance curve “Output Noise Voltage vs Measurement
Bandwidth” shows how the noise varies with RF and measured
bandwidth (1Hz to the indicated frequency). The signal
bandwidth of the OPT301 is indicated on the curves. Noise
can be reduced by filtering the output with a cutoff frequency
equal to the signal bandwidth.
Dynamic response will vary with feedback resistor value as
shown in the typical performance curve “Voltage Output
Responsivity vs Frequency.” Rise time (10% to 90%) will
vary according to the –3dB bandwidth produced by a given
feedback resistor value—
t R ≈ 0. 35
(1)
f
C
Output noise increases in proportion to the square-root of the
feedback resistance, while responsivity increases linearly
with feedback resistance. So best signal-to-noise ratio is
achieved with large feedback resistance. This comes with
the trade-off of decreased bandwidth.
The noise performance of a photodetector is sometimes
characterized by Noise Effective Power (NEP). This is the
radiant power which would produce an output signal equal
to the noise level. NEP has the units of radiant power
(watts). The typical performance curve “Noise Effective
Power vs Measurement Bandwidth” shows how NEP varies
with RF and measurement bandwidth.
where:
tR is the rise time (10% to 90%)
fC is the –3dB bandwidth
LINEARITY PERFORMANCE
Current output of the photodiode is very linear with radiant
power throughout a wide range. Nonlinearity remains below
2
1MΩ
2
1MΩ
4
RF
4
40pF
Gain Adjustment
+50%; –0%
40pF
75Ω
V+
75Ω
λ
100µA
1/2 REF200
5
λ
VO
OPT301
8
OPT301
8
1
V+
100Ω
1
V+
3
3
V–
5
VO
5kΩ
10kΩ
V–
500Ω
100Ω
FIGURE 4. Responsivity (Gain) Adjustment Circuit.
0.01µF
100µA
1/2 REF200
Adjust dark output for 0V.
Trim Range: ±7mV
V–
FIGURE 3. Dark Error (Offset) Adjustment Circuit.
®
OPT301
8
This OPT301 used
as photodiode, only.
2
2
1MΩ
RF
1MΩ
4
40pF
VO =
75Ω
ID RF
75Ω
R2
1kΩ
V–
NC
OPT301
3
V+
NC
5
λ
R1
19kΩ
OPT301
1
R2
4
40pF
5
λ
8
R1 + R2
RF
1
8
ID1
3
2
1MΩ
Advantages: High gain with low resistor values.
Less sensitive to circuit board leakage.
Disadvantage: Higher offset and noise than by using high
value for RF.
RF
4
40pF
FIGURE 5. “T” Feedback Network.
75Ω
5
λ
OPT301
2
1MΩ
RF1
ID2
4
1
8
λ
VO = (ID2 – ID1) RF
3
V+
Bandwidth is reduced to
2.8kHz due to additional
photodiode capacitance.
V–
40pF
75Ω
VO
FIGURE 7. Differential Light Measurement.
6
5
VO = ID1 RF1 + ID2 RF2
OPT301
8
1
V+
2
3
1MΩ
V–
Max linear
input voltage
(V+) –0.6V typ
RF
40pF
2
75Ω
1MΩ
RF2
λ
4
ID
75Ω
λ
5
V+
8
1
+15V
3
–15V
VO = ID2 RF2
R1
1kΩ
IO ≤ 5mA
OPT301
1
5
OPT301
40pF
8
4
IO = I D 1 +
3
RF
R1
V–
FIGURE 8. Current Output Circuit.
FIGURE 6. Summing Output of Two OPT301s.
®
9
OPT301
2
1MΩ
RF
2
4
1MΩ
40pF
λ
Output filter reduces
output noise from
250µV to 195µV.
5
75Ω
λ
+
OPT301
1
VO = IDRF
VZ(1)
VO
10nF
8
1
VZ
5kΩ
5
OPT301
3
–
3.3V
4
40pF
75Ω
8
RF1
3
V+
V–
(pesudo-ground)
FIGURE 10. Output Filter to Reduce Noise.
0.1µF
V+
NOTE: (1) Zener diode or other shunt regulator.
FIGURE 9. Single Power Supply Operation.
2
1MΩ
RF1
INA106
4
10kΩ
40pF
100kΩ
5
2
75Ω
λ
5
Difference Measurement
VO = 10 (VO2 – VO1)
6
VO1 = ID1 RF1
3
10kΩ
100kΩ
1
OPT301
8
1
V+
3
V–
G = 10
2
1MΩ
RF2
100kΩ
4
100kΩ
40pF
1
14
LOG100
3
75Ω
λ
5
VO2 = ID2 RF2
CC
OPT301
8
1
V+
3
V–
FIGURE 11. Differential Light Measurement.
®
OPT301
10
1nF
7
10
Log of Ratio Measurement
(Absorbance)
V
VO = K log O1
VO2
C2
0.1µF
R2
1MΩ
R3
100kΩ
A1
R1
1MΩ
2
1MΩ
C1
0.1µF
4
40pF
20dB/decade
f–3dB =
75Ω
λ
5
1MΩ
R3(2πR2C2)
VO
OPT301
8
FIGURE 12. DC Restoration Rejects Unwanted Steady-State Background Light.
6
1/2
REF200 100µA
100µA
1/2
REF200
1
2
1MΩ
4
10V to 36V
40pF
2N2222
75Ω
λ
OPT301
8
20kΩ
5
3
4-20mA
(4mA Dark)
IN4148
R2
65Ω
R1
22.5kΩ
Calculations shown provide a dark output of 4mA.
Output is 20mA at a photodiode current of
ID max. Values shown are for ID max max = 1µA.
R1 =
R2 =
1.014 X 106
– 994,000Ω
(1 – 2500 ID max)
26,000
– 26,000Ω
(1 – 2500 ID max)
FIGURE 13. 4-20mA Current-Loop Transmitter.
®
11
OPT301