PHILIPS SA5211

INTEGRATED CIRCUITS
SA5211
Transimpedance amplifier (180MHz)
Product specification
Replaces datasheet NE/SA5211 of 1995 Apr 26
IC19 Data Handbook
1998 Oct 07
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
DESCRIPTION
PIN CONFIGURATION
The SA5211 is a 28kΩ transimpedance, wide-band, low noise
amplifier with differential outputs, particularly suitable for signal
recovery in fiber optic receivers. The part is ideally suited for many
other RF applications as a general purpose gain block.
D Package
FEATURES
• Extremely low noise: 1.8pA Hz
• Single 5V supply
• Large bandwidth: 180MHz
• Differential outputs
• Low input/output impedances
• High power supply rejection ratio
• 28kΩ differential transresistance
GND2
1
14
OUT (–)
GND2
2
13
GND2
NC
3
12
OUT (+)
IIN
4
11
GND1
NC
5
10
GND1
VCC1
6
9
GND1
VCC2
7
8
GND1
TOP VIEW
SD00318
Figure 1. Pin Configuration
• Medical and scientific Instrumentation
• Sensor preamplifiers
• Single-ended to differential conversion
• Low noise RF amplifiers
• RF signal processing
APPLICATIONS
• Fiber optic receivers, analog and digital
• Current-to-voltage converters
• Wide-band gain block
ORDERING INFORMATION
DESCRIPTION
14-Pin Plastic Small Outline (SO) Package
TEMPERATURE RANGE
ORDER CODE
DWG #
-40 to +85°C
SA5211D
SOT108-1
ABSOLUTE MAXIMUM RATINGS
SYMBOL
VCC
PARAMETER
RATING
UNIT
6
V
Power supply
TA
Operating ambient temperature range
-40 to +85
°C
TJ
Operating junction temperature range
-55 to +150
°C
Storage temperature range
-65 to +150
°C
1.0
W
TSTG
PD MAX
IIN MAX
θJA
Power dissipation, TA=25°C (still-air)1
Maximum input
current2
Thermal resistance
5
mA
125
°C/W
NOTES:
1. Maximum dissipation is determined by the operating ambient temperature and the thermal resistance:
θJA=125°C/W
2. The use of a pull-up resistor to VCC, for the PIN diode is recommended.
1998 Oct 07
2
853-1799 20142
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
RECOMMENDED OPERATING CONDITIONS
SYMBOL
VCC
PARAMETER
RATING
UNIT
Supply voltage
4.5 to 5.5
V
TA
Ambient temperature range
-40 to +85
°C
TJ
Junction temperature range
-40 to +105
°C
DC ELECTRICAL CHARACTERISTICS
Min and Max limits apply over operating temperature range at VCC=5V, unless otherwise specified. Typical data apply at VCC=5V and TA=25°C.
SYMBOL
Min
Typ
Max
UNIT
VIN
Input bias voltage
PARAMETER
TEST CONDITIONS
0.55
0.8
1.00
V
VO±
Output bias voltage
2.7
3.4
3.7
V
VOS
Output offset voltage
0
130
mV
ICC
Supply current
20
26
31
mA
IOMAX
Output sink/source current1
3
4
mA
IIN
Input current
(2% linearity)
Test Circuit 8,
Procedure 2
±20
±40
µA
IIN MAX
Maximum input current
overload threshold
Test Circuit 8,
Procedure 4
±30
±60
µA
NOTES:
1. Test condition: output quiescent voltage variation is less than 100mV for 3mA load current.
1998 Oct 07
3
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
AC ELECTRICAL CHARACTERISTICS
Typical data and Min and Max limits apply at VCC=5V and TA=25°C
SYMBOL
PARAMETER
TEST CONDITIONS
Min
Typ
Max
UNIT
DC tested RL = ∞
Test Circuit 8, Procedure 1
21
28
36
kΩ
RT
Transresistance (differential output)
RO
Output resistance (differential output)
DC tested
RT
Transresistance (single-ended output)
DC tested
RL = ∞
RO
Output resistance (single-ended output)
DC tested
15
Ω
TA = 25°C
Test circuit 1
180
MHz
f3dB
Bandwidth (-3dB)
RIN
Input resistance
CIN
Input capacitance
∆R/∆V
Transresistance power supply sensitivity
∆R/∆T
Ω
30
10.5
14
18.0
kΩ
200
Ω
4
pF
VCC = 5±0.5V
3.7
%/V
Transresistance ambient temperature sensitivity
∆TA = TA MAX-TA MIN
0.025
%/°C
IN
RMS noise current spectral density (referred to
input)
Test Circuit 2
f = 10MHz
TA = 25°C
1.8
pA/√Hz
IT
Integrated RMS noise current over the bandwidth
(referred to input)
TA = 25°C
Test Circuit 2
∆f = 50MHz
13
CS=01
∆f = 100MHz
20
∆f = 200MHz
35
CS=1pF
ratio2
∆f = 50MHz
13
∆f = 100MHz
21
∆f = 200MHz
41
nA
nA
DC tested, ∆VCC = 0.1V
Equivalent AC
Test Circuit 3
23
32
dB
PSRR
Power supply rejection
(VCC1 = VCC2)
PSRR
Power supply rejection ratio2 (VCC1)
DC tested, ∆VCC = 0.1V
Equivalent AC
Test Circuit 4
23
32
dB
PSRR
Power supply rejection ratio2 (VCC2)
DC tested, ∆VCC = 0.1V
Equivalent AC
Test Circuit 5
45
65
dB
PSRR
Power supply rejection ratio (ECL configuration)2
23
dB
VOMAX
Maximum differential output voltage swing
3.2
VP-P
VIN MAX
tR
f = 0.1MHz
Test Circuit 6
RL = ∞
Test Circuit 8, Procedure 3
1.7
Maximum input amplitude for output duty cycle of
50±5%3
Test Circuit 7
160
Rise time for 50mV output signal4
Test Circuit 7
mVP-P
0.8
1.8
ns
NOTES:
1. Package parasitic capacitance amounts to about 0.2pF
2. PSRR is output referenced and is circuit board layout dependent at higher frequencies. For best performance use RF filter in VCC lines.
3. Guaranteed by linearity and overload tests.
4. tR defined as 20-80% rise time. It is guaranteed by -3dB bandwidth test.
1998 Oct 07
4
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TEST CIRCUITS
SINGLE-ENDED
DIFFERENTIAL
NETWORK ANALYZER
RT [
S-PARAMETER TEST SET
PORT 1
V OUT
V IN
RO [ ZO
PORT 2
R + 2 @ S21 @ R
Ť11 )* S22
Ť * 33
S22
RT +
V OUT
V IN
R O + 2Z O
R + 4 @ S21 @ R
Ť11 )* S22
Ť * 66
S22
5V
VCC1
0.1µF
ZO = 50
VCC2
33
OUT
0.1µF
ZO = 50
R = 1k
IN
DUT
33
0.1µF
OUT
RL = 50
50
GND1
GND2
Test Circuit 1
SPECTRUM ANALYZER
5V
VCC1
OUT
NC
IN
AV = 60DB
VCC2
33
DUT
33
0.1µF
ZO = 50
0.1µF
OUT
RL = 50
GND1
GND2
Test Circuit 2
Figure 2. Test Circuits 1 and 2
1998 Oct 07
5
SD00319
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TEST CIRCUITS (Continued)
NETWORK ANALYZER
5V
10µF
S-PARAMETER TEST SET
0.1µF
PORT 1
PORT 2
CURRENT PROBE
1mV/mA
10µF
0.1µF
16
VCC1
CAL
VCC2
33
0.1µF
OUT
50
100
BAL.
IN
33
TRANSFORMER
NH0300HB
TEST
UNBAL.
OUT
0.1µF
GND1
GND2
Test Circuit 3
NETWORK ANALYZER
5V
10µF
S-PARAMETER TEST SET
0.1µF
PORT 1
CURRENT PROBE
1mV/mA
10µF
0.1µF
5V
PORT 2
16
VCC2
10µF
CAL
VCC1
33
0.1µF
OUT
0.1µF
IN
50
100
BAL.
33
TRANSFORMER
NH0300HB
TEST
UNBAL.
OUT
GND1
GND2
0.1µF
Test Circuit 4
Figure 3. Test Circuits 3 and 4
1998 Oct 07
6
SD00320
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TEST CIRCUITS (Continued)
NETWORK ANALYZER
5V
10µF
S-PARAMETER TEST SET
0.1µF
PORT 1
CURRENT PROBE
1mV/mA
10µF
0.1µF
5V
PORT 2
16
VCC2
VCC1
10µF
CAL
33
0.1µF
OUT
0.1µF
IN
50
100
BAL.
33
TRANSFORMER
NH0300HB
TEST
UNBAL.
OUT
0.1µF
GND2
GND1
Test Circuit 5
NETWORK ANALYZER
S-PARAMETER TEST SET
GND
PORT 1
PORT 2
CURRENT PROBE
1mV/mA
10µF
0.1µF
16
GND1
CAL
GND2
33
0.1µF
OUT
50
100
BAL.
IN
33
TRANSFORMER
NH0300HB
TEST
UNBAL.
OUT
VCC1
5.2V
VCC2
0.1µF
10µF
0.1µF
Test Circuit 6
Figure 4. Test Circuits 5 and 6
1998 Oct 07
7
SD00321
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TEST CIRCUITS (Continued)
PULSE GEN.
VCC1
VCC2
33
0.1µF
OUT
0.1µF 1k IN
A
DUT
OUT
ZO = 50Ω
OSCILLOSCOPE
33
B
0.1µF
ZO = 50Ω
50
GND1
GND2
Measurement done using
differential wave forms
Test Circuit 7
SD00322
Figure 5. Test Circuit 7
1998 Oct 07
8
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TEST CIRCUITS (Continued)
Typical Differential Output Voltage
vs Current Input
5V
+
OUT +
IN
VOUT (V)
DUT
–
OUT –
IIN (µA)
GND1
GND2
2.00
DIFFERENTIAL OUTPUT VOLTAGE (V)
1.60
1.20
0.80
0.40
0.00
–0.40
–0.80
–1.20
–1.60
–2.00
–100
–80
–60
–40
–20
0
20
40
60
80
100
CURRENT INPUT (µA)
NE5211 TEST CONDITIONS
Procedure 1
RT measured at 15µA
RT = (VO1 – VO2)/(+15µA – (–15µA))
Where: VO1 Measured at IIN = +15µA
VO2 Measured at IIN = –15µA
Procedure 2
Linearity = 1 – ABS((VOA – VOB) / (VO3 – VO4))
Where: VO3 Measured at IIN = +30µA
VO4 Measured at IIN = –30µA
+ R T @ () 30A) ) V
OA
OB
V
+ R T @ (* 30A) ) V
OB
OB
V
Procedure 3
VOMAX = VO7 – VO8
Where: VO7 Measured at IIN = +65µA
VO8 Measured at IIN = –65µA
Procedure 4
IIN Test Pass Conditions:
VO7 – VO5 > 20mV and V06 – VO5 > 50mV
Where: VO5 Measured at IIN = +40µA
VO6 Measured at IIN = –400µA
VO7 Measured at IIN = +65µA
VO8 Measured at IIN = –65µA
Test Circuit 8
Figure 6. Test Circuit 8
1998 Oct 07
9
SD00331
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TYPICAL PERFORMANCE CHARACTERISTICS
NE5211 Supply Current
vs Temperature
28
26
5.0V
24
4.5V
22
DIFFERENTIAL OUTPUT VOLTAGE (V)
OUTPUT BIAS VOLTAGE (V)
TOTAL SUPPLY CURRENT (mA)
(ICC1+ I CC2)
2.0
3.50
30
5.5V
VCC = 5.0V
3.45
3.40
3.35
PIN 14
PIN 12
3.30
20
3.25
18
–60 –40 –20
0
–60 –40 –20
20 40 60 80 100 120 140
NE5211 Input Bias Voltage
vs Temperature
NE5211 Output Bias Voltage
vs Temperature
0
–55°C
+25°C
+125°C
–2.0
–100.0
700
4.5V
650
–60 –40 –20
0
5.0V
3.3
3.1
4.5V
2.9
2.7
–60 –40 –20
20 40 60 80 100 120 140
DIFFERENTIAL OUTPUT VOLTAGE (V)
750
5.5V
3.7
3.5
AMBIENT TEMPERATURE (°C)
0
INPUT CURRENT (µA)
0
20 40 60 80 100 120 140
5.5V
4.5V
0
4.5V
5.0V
–2.0
–100.0
5.5V
0
INPUT CURRENT (µA)
+100.0
NE5211 Output Voltage
vs Input Current
NE5211 Differential Output Swing
vs Temperature
4.0
VOS = VOUT12 – VOUT14
0
4.5V
–40
5.0V
–60
5.5V
–100
–120
–140
–60 –40 –20
0
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
DIFFERENTIAL OUTPUT SWING (V)
40
+100.0
5.0V
AMBIENT TEMPERATURE (°C)
NE5211 Output Offset Voltage
vs Temperature
+85°C
NE5211 Differential Output Voltage
vs Input Current
3.8
DC TESTED
3.6
RL = ∞
3.4
5.5V
4.5
OUTPUT VOLTAGE (V)
INPUT BIAS VOLTAGE (mV)
5.5V
OUTPUT BIAS VOLTAGE (V)
3.9
800
OUTPUT OFFSET VOLTAGE (mV)
–55°C
+25°C
2.0
PIN 14
+125°C
+85°C
4.1
850
–80
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
900
–20
0
AMBIENT TEMPERATURE (°C)
950
20
NE5211 Output Voltage
vs Input Current
NE5211 Output Bias Voltage
vs Temperature
3.2
3.0
5.0V
2.8
2.6
4.5V
+125°C
–55°C
+85°C +125°C
+25°C
+25°C
+85°C
–55°C
+125°C
+85°C
2.4
2.2
–60 –40 –20
0
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
2.5
–100.0
–55°C +25°C
0
+100.0
INPUT CURRENT (µA)
SD00332
Figure 7. Typical Performance Characteristics
1998 Oct 07
10
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
17
17
5.5V
16
15
15
14
14
5.0V
13
PIN 12
TA = 25°C
RL = 50Ω
12
11
5.5V
16
GAIN (dB)
GAIN (dB)
NE5211 Differential Transresistance
vs Temperature
NE5211 Gain vs Frequency
DIFFERENTIAL TRANSRESISTANCE (kΩ )
NE5211 Gain vs Frequency
4.5V
13
12
11
10
10
9
9
8
0.1
8
0.1
1
10
FREQUENCY (MHz)
5.0V
100
PIN 14
TA = 25°C
RL = 50Ω
4.5V
1
10
FREQUENCY (MHz)
100
33
DC TESTED
32
RL = ∞
31
30
29
28
5.5V
5.0V
4.5V
27
–60 –40 –20 0
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
NE5211 Gain vs Frequency
17
–55°C
16
12
85°C
25°C
11
14
13
12
10
10
9
9
8
0.1
1
10
FREQUENCY (MHz)
PIN 12
SINGLE-ENDED
RL = 50Ω
100
143
140
8
0.1
120
0
12
9
203
16
15
60
13
10
191
17
120
14
11
160
155
167
179
FREQUENCY (MHz)
NE5211 Gain and Phase
Shift vs Frequency
15
4.5V
100
–60 –40 –20 0
0
16
GAIN (dB)
5.0V
180
10
1
10
FREQUENCY (MHz)
17
220
5.5V
20
NE5211 Gain and Phase
Shift vs Frequency
NE5211 Bandwidth
vs Temperature
200
25°C
8
0.1
100
VCC = 5.0V
TA = 25°C
30
85°C
11
PIN 12
SINGLE-ENDED
RL = 50Ω
40
125°C
PIN 14
VCC = 5V
PIN 12
VCC = 5V
TA = 25°C
–60
GAIN (dB)
PIN 12
VCC = 5V
POPULATION (%)
125°C
13
PHASE (o)
14
BANDWIDTH (MHz)
50
15
GAIN (dB)
GAIN (dB)
15
60
–55°C
16
14
13
12
11
10
–120
1
10
FREQUENCY (MHz)
100
120
PIN 14
VCC = 5V
TA = 25°C
PHASE (o)
NE5211 Gain vs Frequency
17
NE5211 Typical
Bandwidth Distribution
(70 Parts from 3 Wafer Lots)
270
9
8
0.1
1
10
FREQUENCY (MHz)
100
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
SD00333
Figure 8. Typical Performance Characteristics (cont.)
1998 Oct 07
11
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
NE5211 Output Resistance
vs Temperature
NE5211 Output Resistance
vs Temperature
18
16
PIN 14
15
PIN 12
14
13
–60 –40 –20
0
17
16
5.0V
14
OUTPUT RESISTANCE (Ω )
OUTPUT RESISTANCE (Ω )
PIN 12
TA = 25°C
25
4.5V
5.0V
15
5.5V
10
5
0
0.1
1
10
100
VCC = 5.0V
+85°C
+25°C
–55°C
30
20
10
0
0.1
1
10
0
20 40 60 80 100 120 140
80
60
VCC = 5.0V
50
PIN 12
40
30
20
10
100
0
0.1
PIN 14
1
10
100
FREQUENCY (MHz)
NE5211 Group Delay
vs Frequency
10
40
8
VCC1 = VCC2 = 5.0V
∆VCC = ±0.1V
DC TESTED
OUTPUT REFERRED
6
DELAY (ns)
POWER SUPPLY REJECTION RATIO (dB)
5.5V
70
FREQUENCY (MHz)
NE5211 Power Supply Rejection Ratio
vs Temperature
36
15
NE5211 Output Resistance
vs Frequency
+125°C
40
FREQUENCY (MHz)
38
5.0V
AMBIENT TEMPERATURE (°C)
80
50
4.5V
16
14
–60 –40 –20
20 40 60 80 100 120 140
70
60
PIN 14
DC TESTED
17
NE5211 Output Resistance
vs Frequency
40
20
0
18
AMBIENT TEMPERATURE (°C)
NE5211 Output Resistance
vs Frequency
30
5.5V
13
–60 –40 –20
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
35
4.5V
15
OUTPUT RESISTANCE (Ω )
17
19
PIN 12
DC TESTED
OUTPUT RESISTANCE (Ω )
VCC = 5.0V
DC TESTED
OUTPUT RESISTANCE (Ω )
OUTPUT RESISTANCE (Ω )
18
NE5211 Output Resistance
vs Temperature
34
4
2
0
32
30
0.1 20 40
28
–60 –40 –20
60 80 100 120 140 160 180 200
FREQUENCY (MHz)
0
20 40 60 80 100 120 140
AMBIENT TEMPERATURE (°C)
SD00335
Figure 9. Typical Performance Characteristics (cont.)
1998 Oct 07
12
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
Output Step Response
VCC = 5V
TA = 25°C
20mV/Div
0
2
4
6
8
10
(ns)
12
14
16
18
20
SD00334
Figure 10. Typical Performance Characteristics (cont.)
Q11 – Q12 are bonded to an external pin, VCC2, in order to reduce
the feedback to the input stage. The output impedance is about 17Ω
single-ended. For ease of performance evaluation, a 33Ω resistor is
used in series with each output to match to a 50Ω test system.
THEORY OF OPERATION
Transimpedance amplifiers have been widely used as the
preamplifier in fiber-optic receivers. The SA5211 is a wide bandwidth
(typically 180MHz) transimpedance amplifier designed primarily for
input currents requiring a large dynamic range, such as those
produced by a laser diode. The maximum input current before
output stage clipping occurs at typically 50µA. The SA5211 is a
bipolar transimpedance amplifier which is current driven at the input
and generates a differential voltage signal at the outputs. The
forward transfer function is therefore a ratio of the differential output
voltage to a given input current with the dimensions of ohms. The
main feature of this amplifier is a wideband, low-noise input stage
which is desensitized to photodiode capacitance variations. When
connected to a photodiode of a few picoFarads, the frequency
response will not be degraded significantly. Except for the input
stage, the entire signal path is differential to provide improved
power-supply rejection and ease of interface to ECL type circuitry. A
block diagram of the circuit is shown in Figure 11. The input stage
(A1) employs shunt-series feedback to stabilize the current gain of
the amplifier. The transresistance of the amplifier from the current
source to the emitter of Q3 is approximately the value of the
feedback resistor, RF=14.4kΩ. The gain from the second stage (A2)
and emitter followers (A3 and A4) is about two. Therefore, the
differential transresistance of the entire amplifier, RT is
RT
BANDWIDTH CALCULATIONS
The input stage, shown in Figure 13, employs shunt-series feedback
to stabilize the current gain of the amplifier. A simplified analysis can
determine the performance of the amplifier. The equivalent input
capacitance, CIN, in parallel with the source, IS, is approximately
7.5pF, assuming that CS=0 where CS is the external source
capacitance.
Since the input is driven by a current source the input must have a
low input resistance. The input resistance, RIN, is the ratio of the
incremental input voltage, VIN, to the corresponding input current, IIN
and can be calculated as:
V
RF
R IN + IN +
+ 14.4K + 203W
71
I IN
1 ) A VOL
More exact calculations would yield a higher value of 200Ω.
Thus CIN and RIN will form the dominant pole of the entire amplifier;
f *3dB +
V
(diff)
+ OUT
+ 2R F + 2(14.4K) + 28.8kW
I IN
Assuming typical values for RF = 14.4kΩ, RIN = 200Ω, CIN = 4pF
The single-ended transresistance of the amplifier is typically 14.4kΩ.
f *3dB +
The simplified schematic in Figure 12 shows how an input current is
converted to a differential output voltage. The amplifier has a
1
+ 200MHz
2p 4pF 200W
The operating point of Q1, Figure 12, has been optimized for the
lowest current noise without introducing a second dominant pole in
the pass-band. All poles associated with subsequent stages have
been kept at sufficiently high enough frequencies to yield an overall
single pole response. Although wider bandwidths have been
achieved by using a cascade input stage configuration, the present
solution has the advantage of a very uniform, highly desensitized
frequency response because the Miller effect dominates over the
external photodiode and stray capacitances. For example, assuming
a source capacitance of 1pF, input stage voltage gain of 70, RIN =
single input for current which is referenced to Ground 1. An input
current from a laser diode, for example, will be converted into a
voltage by the feedback resistor RF. The transistor Q1 provides most
of the open loop gain of the circuit, AVOL≈70. The emitter follower Q2
minimizes loading on Q1. The transistor Q4, resistor R7, and VB1
provide level shifting and interface with the Q15 – Q16 differential
pair of the second stage which is biased with an internal reference,
VB2. The differential outputs are derived from emitter followers Q11 –
Q12 which are biased by constant current sources. The collectors of
1998 Oct 07
1
2p R IN C IN
13
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
Assuming a data rate of 400 Mbaud (Bandwidth, B=200MHz), the
noise parameter Z may be calculated as:1
60Ω then the total input capacitance, CIN = 4 pF which will lead to
only a 12% bandwidth reduction.
Z +
NOISE
Most of the currently installed fiber-optic systems use non-coherent
transmission and detect incident optical power. Therefore, receiver
noise performance becomes very important. The input stage
achieves a low input referred noise current (spectral density) of
2.9pA/√Hz. The transresistance configuration assures that the
external high value bias resistors often required for photodiode
biasing will not contribute to the total noise system noise. The
equivalent input RMS noise current is strongly determined by the
quiescent current of Q1, the feedback resistor RF, and the
bandwidth; however, it is not dependent upon the internal
Miller-capacitance. The measured wideband noise was 41nA RMS
in a 200MHz bandwidth.
where Z is the ratio of RMS noise output to the peak response to a
single hole-electron pair. Assuming 100% photodetector quantum
efficiency, half mark/half space digital transmission, 850nm
lightwave and using Gaussian approximation, the minimum required
optical power to achieve 10-9 BER is:
P avMIN + 12 hc B Z + 12 @ 2.3 @ 10 *19
l
200 @ 10 6 (1281) + 719nW + * 31.5dBm
+ 1139nW + * 29.4dBm
where h is Planck’s Constant, c is the speed of light, λ is the
wavelength. The minimum input current to the SA5211, at this input
power is:
DYNAMIC RANGE CALCULATIONS
The electrical dynamic range can be defined as the ratio of
maximum input current to the peak noise current:
I avMIN + qP avMIN l
hc
Electrical dynamic range, DE, in a 200MHz bandwidth assuming
IINMAX = 60µA and a wideband noise of IEQ=41nARMS for an
external source capacitance of CS = 1pF.
DE +
I EQ
41 @ 10 *9
+
+ 1281
qB
(1.6 @ 10 *19)(200 @ 10 6)
*9
@ 10 *19
+ 707 @ 10 @ 1.6
2.3 @ 10 *19
= 500nA
(Max. input current)
(Peak noise current)
D E(dB) + 20 log
1 @ Joule @ q + I
Joule sec
Choosing the maximum peak overload current of IavMAX=60µA, the
maximum mean optical power is:
(60 @ 10 *6)
(Ǹ2 41 10 *9)
P avMAX +
(60mA)
D E(dB) + 20 log
+ 60dB
(58nA)
hcI avMAX
*19
+ 2.3 @ 10 *19 60 @ 10mA
lq
1.6 @ 10
+ 86mW or * 10.6dBm (optical)
In order to calculate the optical dynamic range the incident optical
power must be considered.
Thus the optical dynamic range, DO is:
For a given wavelength λ;
DO = PavMAX - PavMIN = -4.6 -(-29.4) = 24.8dB.
D O + P avMAX * P avMIN + * 31.5 * (* 10.6)
+ 20.8dB
Energy of one Photon = hc watt sec (Joule)
l
Where h=Planck’s Constant = 6.6 × 10-34 Joule sec.
1. S.D. Personick, Optical Fiber Transmission Systems,
Plenum Press, NY, 1981, Chapter 3.
c = speed of light = 3 × 108 m/sec
c / λ = optical frequency
P
No. of incident photons/sec= hs where P=optical incident power
l
P
No. of generated electrons/sec = h @ hs
l
OUTPUT +
A3
INPUT
where η = quantum efficiency
+
A1
A2
no. of generated electron hole paris
no. of incident photons
P
RF
A4
NI + h @ hs @ e Amps (Coulombsńsec.)
l
where e = electron charge = 1.6 ×
10-19
OUTPUT –
SD00327
Figure 11. SA5211 – Block Diagram
Coulombs
h@e
Responsivity R = hs Amp/watt
l
This represents the maximum limit attainable with the SA5211
operating at 200MHz bandwidth, with a half mark/half space digital
transmission at 850nm wavelength.
I + P@R
1998 Oct 07
14
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
VCC1
VCC2
R3
R1
Q2
INPUT
R12
Q4
Q11
+
Q3
Q1
R13
Q12
Q15
R2
R14
GND1
Q16
R7
PHOTODIODE
OUT–
R15
+
OUT+
VB2
R5
R4
GND2
SD00328
Figure 12. Transimpedance Amplifier
Pins 8–11, and Ground 2, Pins 1 and 2 on opposite ends of the
SO14 package. This ground-plane stripe also provides isolation
between the output return currents flowing to either VCC2 or Ground
2 and the input photodiode currents to flowing to Ground 1. Without
this ground-plane stripe and with large lead inductances on the
board, the part may be unstable and oscillate near 800MHz. The
easiest way to realize that the part is not functioning normally is to
measure the DC voltages at the outputs. If they are not close to their
quiescent values of 3.3V (for a 5V supply), then the circuit may be
oscillating. Input pin layout necessitates that the photodiode be
physically very close to the input and Ground 1. Connecting Pins 3
and 5 to Ground 1 will tend to shield the input but it will also tend to
increase the capacitance on the input and slightly reduce the
bandwidth.
VCC
IC1
R1
INPUT
Q2
IB
IIN
R3
Q3
Q1
R2
VIN
IF
VEQ3
RF
R4
As with any high-frequency device, some precautions must be
observed in order to enjoy reliable performance. The first of these is
the use of a well-regulated power supply. The supply must be
capable of providing varying amounts of current without significantly
changing the voltage level. Proper supply bypassing requires that a
good quality 0.1µF high-frequency capacitor be inserted between
VCC1 and VCC2, preferably a chip capacitor, as close to the package
pins as possible. Also, the parallel combination of 0.1µF capacitors
with 10µF tantalum capacitors from each supply, VCC1 and VCC2, to
the ground plane should provide adequate decoupling. Some
applications may require an RF choke in series with the power
supply line. Separate analog and digital ground leads must be
maintained and printed circuit board ground plane should be
employed whenever possible.
SD00329
Figure 13. Shunt-Series Input Stage
APPLICATION INFORMATION
Package parasitics, particularly ground lead inductances and
parasitic capacitances, can significantly degrade the frequency
response. Since the SA5211 has differential outputs which can feed
back signals to the input by parasitic package or board layout
capacitances, both peaking and attenuating type frequency
response shaping is possible. Constructing the board layout so that
Ground 1 and Ground 2 have very low impedance paths has
produced the best results. This was accomplished by adding a
ground-plane stripe underneath the device connecting Ground 1,
1998 Oct 07
Figure 14 depicts a 50Mb/s TTL fiber-optic receiver using the
BPF31, 850nm LED, the SA5211 and the SA5214 post amplifier.
15
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
+VCC
GND
47µF
C1
C2
.01µF
D1
LED
1
LED
IN1B
20
CPKDET
3
THRESH
4
GNDA
5
FLAG
100pF
IN1A
19
L2
10µH
6
C10
C11
µ
.01µF
10 F
L3
10µH
C12
C13
.01µF
JAM
7
VCCD
8
VCCA
9
GNDD
10
TTLOUT
CAZP 18
CAZN
NE5214
2
17
GND
VCC
7
9
GND
VCC
6
10
GND
NC
5
IIN
4
8
100pF
C9
R3
47k
L1
10µH
C7
C8
11
0.1µF
GND
NE5210
R2
220
OUT1B 16
12
OUT
NC
3
IN8B
15
13
GND
GND
2
OUT1A
14
14
OUT
GND
1
IN8A
13
RHYST
12
C4
.01µF
R1
100
C5
1.0µF
C3
10µF
.01µF
C6
BPF31
OPTICAL
INPUT
RPKDET 11
10µF
R4
4k
VOUT (TTL)
NOTE:
The NE5210/NE5217 combination can operate at data rates in excess of 100Mb/s NRZ
The capacitor C7 decreases the NE5210 bandwidth to improve overall S/N ratio in the DC–50MHz band, but does create extra high frequency noise
on the NE5210 VCC pin(s).
Figure 14. A 50Mb/s Fiber Optic Receiver
1998 Oct 07
16
SD00330
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
1
14
OUT (–)
GND 2
2
13
GND 2
GND 2
12
3
OUT (+)
NC
INPUT
11
4
NC
10
GND 1
GND 1
5
GND 1
VCC1
9
6
ECN No.: 06027
1992 Mar 13
VCC 2
7
8
GND 1
SD00488
Figure 15. SA5211 Bonding Diagram
carriers, it is impossible to guarantee 100% functionality through this
process. There is no post waffle pack testing performed on
individual die.
Die Sales Disclaimer
Due to the limitations in testing high frequency and other parameters
at the die level, and the fact that die electrical characteristics may
shift after packaging, die electrical parameters are not specified and
die are not guaranteed to meet electrical characteristics (including
temperature range) as noted in this data sheet which is intended
only to specify electrical characteristics for a packaged device.
Since Philips Semiconductors has no control of third party
procedures in the handling or packaging of die, Philips
Semiconductors assumes no liability for device functionality or
performance of the die or systems on any die sales.
All die are 100% functional with various parametrics tested at the
wafer level, at room temperature only (25°C), and are guaranteed to
be 100% functional as a result of electrical testing to the point of
wafer sawing only. Although the most modern processes are
utilized for wafer sawing and die pick and place into waffle pack
1998 Oct 07
Although Philips Semiconductors typically realizes a yield of 85%
after assembling die into their respective packages, with care
customers should achieve a similar yield. However, for the reasons
stated above, Philips Semiconductors cannot guarantee this or any
other yield on any die sales.
17
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
SO14: plastic small outline package; 14 leads; body width 3.9 mm
1998 Oct 07
18
SOT108-1
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
NOTES
1998 Oct 07
19
Philips Semiconductors
Product specification
Transimpedance amplifier (180MHz)
SA5211
Data sheet status
Data sheet
status
Product
status
Definition [1]
Objective
specification
Development
This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.
Preliminary
specification
Qualification
This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make chages at any time without notice in order to
improve design and supply the best possible product.
Product
specification
Production
This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.
[1] Please consult the most recently issued datasheet before initiating or completing a design.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
 Copyright Philips Electronics North America Corporation 1998
All rights reserved. Printed in U.S.A.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
Date of release: 10-98
Document order number:
1998 Oct 07
20
9397 750 04624