Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 DESCRIPTION PIN CONFIGURATION The NE5210 is a 7kΩ 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 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 FEATURES • Low noise: 3.5pA/√Hz • Single 5V supply • Large bandwidth: 280MHz • Differential outputs • Low input/output impedances • High power supply rejection ratio • High overload threshold current • Wide dynamic range • 7kΩ differential transresistance TOP VIEW SD00318 • Wideband gain block • 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 ORDERING INFORMATION DESCRIPTION 14-Pin Plastic Small Outline (SO) Package TEMPERATURE RANGE ORDER CODE DWG # 0 to +70°C NE5210D SOT108-1 ABSOLUTE MAXIMUM RATINGS SYMBOL VCC PARAMETER RATING Power supply UNIT 6 V TA Operating ambient temperature range 0 to +70 °C TJ Operating junction temperature range -55 to +150 °C Storage temperature range -65 to +150 °C TSTG PDMAX Power dissipation, TA=25°C (still air)1 IINMAX Maximum input current2 1.0 W 5 mA 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. RECOMMENDED OPERATING CONDITIONS SYMBOL VCC PARAMETER RATING UNIT Supply voltage 4.5 to 5.5 V TA Ambient temperature range 0 to +70 °C TJ Junction temperature range 0 to +90 °C 1995 Apr 26 1 853-1654 15170 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 DC ELECTRICAL CHARACTERISTICS Min and Max limits apply over operating temperature range at VCC=5V, unless otherwise specified. Typical data applies at VCC=5V and TA=25°C. SYMBOL PARAMETER TEST CONDITIONS LIMITS Min Typ Max UNIT VIN Input bias voltage 0.6 0.8 0.95 V VO± Output bias voltage 2.8 3.3 3.7 V VOS Output offset voltage 0 80 mV ICC Supply current 21 26 32 mA IOMAX Output sink/source current1 3 4 mA IIN Input current (2% linearity) Test Circuit 8, Procedure 2 ±120 ±160 µA IINMAX Maximum input current overload threshold Test Circuit 8, Procedure 4 ±160 ±240 µA NOTES: 1. Test condition: output quiescent voltage variation is less than 100mV for 3mA load current. AC ELECTRICAL CHARACTERISTICS Typical data and Min/Max limits apply at VCC=5V and TA=25°C. SYMBOL PARAMETER TEST CONDITIONS LIMITS Min Typ Max UNIT RT Transresistance (differential output) DC tested, RL=∞ Test Circuit 8, Procedure 1 4.9 7 10 kΩ RO Output resistance (differential output) DC tested 16 30 42 Ω RT Transresistance (single-ended output) DC tested, RL=∞ 2.45 3.5 5 kΩ RO Output resistance (single-ended output) DC tested 8 15 21 Ω f3dB Bandwidth (-3dB) Test Circuit 1, TA=25°C 200 280 RIN Input resistance 60 Ω CIN Input capacitance 7.5 pF ∆R/∆V Transresistance power supply sensitivity ∆R/∆T IN IT MHz VCC=5±0.5V 9.6 20 %/V Transresistance ambient temperature sensitivity ∆TA=TA MAX-TA MIN 0.05 0.1 %/°C RMS noise current spectral density (referred to input) f=10MHz, TA=25°C Test Circuit 2 3.5 6 pA/√Hz Integrated RMS noise current over the bandwidth (referred to input) CS=01 CS=1pF TA=25°C Test Circuit 2 ∆f=100MHz 37 ∆f=200MHz 56 ∆f=300MHz 71 ∆f=100MHz 40 ∆f=200MHz 66 ∆f=300MHz 89 nA PSRR Power supply rejection ratio2 (VCC1=VCC2) DC tested, ∆VCC=0.1V Equivalent AC test circuit 3 20 36 dB PSRR Power supply rejection ratio2 (VCC1) DC tested, ∆VCC=0.1V Equivalent AC test circuit 4 20 36 dB PSRR Power supply rejection ratio2 (VCC2) DC tested, ∆VCC=0.1V Equivalent AC test circuit 5 65 dB f=0.1MHz, Test Circuit 6 23 dB PSRR 1995 Apr 26 Power supply rejection configuration) ratio2 (ECL 2 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 AC ELECTRICAL CHARACTERISTICS (Continued) SYMBOL PARAMETER TEST CONDITIONS VOMAX Maximum output voltage swing differential VINMAX tR LIMITS Min Typ RL=∞ Test Circuit 8, Procedure 3 2.4 3.2 Maximum input amplitude for output duty cycle of 50±5%3 Test Circuit 7 650 Rise time for 50 mVP-P output signal4 Test Circuit 7 UNIT Max VP-P mVP-P 0.8 1.2 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 line. 3. Guaranteed by linearity and overload tests. 4. tR defined as 20-80% rise time. It is guaranteed by a -3dB bandwidth test. 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 11 S22 33 S22 RT V OUT V IN R O 2Z O R 4 S21 R 11 S22 66 S22 5V VCC1 0.1µF ZO = 50 VCC2 OUT 33 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 1995 Apr 26 3 SD00319 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 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 1995 Apr 26 4 SD00320 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 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 GND1 0.1µF GND2 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 1995 Apr 26 5 SD00321 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 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 1995 Apr 26 6 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 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 –400 –320 –240 –160 –80 0 80 160 240 320 400 CURRENT INPUT (µA) NE5210 TEST CONDITIONS Procedure 1 RT measured at 60µA RT = (VO1 – VO2)/(+60µA – (–60µA)) Where: VO1 Measured at IIN = +60µA VO2 Measured at IIN = –60µA Procedure 2 Linearity = 1 – ABS((VOA – VOB) / (VO3 – VO4)) Where: VO3 Measured at IIN = +120µA VO4 Measured at IIN = –120µA R T ( 120A) V OA OB V R T ( 120A) V OB OB V Procedure 3 VOMAX = VO7 – VO8 Where: VO7 Measured at IIN = +260µA VO8 Measured at IIN = –260µA Procedure 4 IIN Test Pass Conditions: VO7 – VO5 > 20mV and V06 – VO5 > 20mV Where: VO5 Measured at IIN = +160µA VO6 Measured at IIN = –160µA VO7 Measured at IIN = +260µA VO8 Measured at IIN = –260µA Test Circuit 8 1995 Apr 26 7 SD00323 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 TYPICAL PERFORMANCE CHARACTERISTICS NE5210 Supply Current vs Temperature NE5210 Output Bias Voltage vs Temperature 28 26 24 22 20 10 20 30 40 50 60 70 3.42 3.38 PIN 12 3.34 AMBIENT TEMPERATURE (°C) 10 20 30 40 50 60 70 DIFFERENTIAL OUTPUT VOLTAGE (V) PIN 14 OUTPUT BIAS VOLTAGE (V) 5.5V 5.0V 4.5V 800 750 10 20 30 40 50 60 70 3.9 3.5 +125°C +85°C 0 INPUT CURRENT (µA) 3.1 4.5V 2.9 10 20 30 40 50 60 70 80 2.0 5.5V 4.5V 0 4.5V 5.0V –2.0 –300.0 DIFFERENTIAL OUTPUT SWING (V) 0 4.5V –20 5.0V –40 5.5V –60 80 4.0 3.8 DC TESTED RL = ∞ 3.6 5.5V 3.4 3.2 5.0V 3.0 2.8 4.5V 2.6 2.4 2.2 –10 0 10 20 30 40 50 60 70 AMBIENT TEMPERATURE (°C) 80 5.5V 0 INPUT CURRENT (µA) +300.0 Differential Output Voltage vs Input Current DIFFERENTIAL OUTPUT VOLTAGE (V) NE5210 Differential Output Swing vs Temperature VOS = VOUT12 – VOUT14 +300.0 5.0V AMBIENT TEMPERATURE (°C) 20 AMBIENT TEMPERATURE (°C) 5.0V 3.3 2.7 –10 0 80 NE5210 Output Offset Voltage vs Temperature 10 20 30 40 50 60 70 5.5V 3.7 AMBIENT TEMPERATURE (°C) –80 –10 0 3.0 Differential Output Voltage vs Input Current 4.1 700 –10 0 –55°C 2.5 –300.0 80 NE5210 Output Bias Voltage vs Temperature 900 850 +125°C AMBIENT TEMPERATURE (°C) NE5210 Input Bias Voltage vs Temperature INPUT BIAS VOLTAGE (mV) PIN 14 3.30 –10 0 80 +25°C +85°C VCC = 5.0V 3.46 OUTPUT VOLTAGE (V) 30 18 –10 0 OUTPUT OFFSET VOLTAGE (mV) 4.5 3.50 OUTPUT BIAS VOLTAGE (V) TOTAL SUPPLY CURRENT (mA) (I CC1+ I CC2) 32 Output Voltage vs Input Current 2.0 0 –55°C –2.0 –300.0 +25°C +85°C +125°C 0 INPUT CURRENT (µA) +300.0 SD00324 1995 Apr 26 8 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) 8 5.5V 7 5.5V 6 4.5V 4 5.0V 3 5 4.5V 4 5.0V 3 2 2 1 1 0 0 –1 –1 10 100 FREQUENCY (MHz) 1000 1 Gain vs Frequency –55°C 6 –55°C 4 3 +125°C 25°C 2 4 3 0 –1 –1 10 100 FREQUENCY (MHz) 1000 180 PIN 12 VCC = 5V TA = 25°C 90 4 0 3 2 6 –90 1 GAIN (dB) 5 –180 10 100 FREQUENCY (MHz) 1000 7.8 7.6 5.5V 5.0V 4.5V 7.4 –10 0 10 20 30 40 50 60 70 80 PIN 12 SINGLE-ENDED 400 5.5V RL = Ω 350 5.0V 300 4.5V 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE (°C) NE5210 Typical Bandwidth Distribution (70 Parts from 4 Wafer Lots) PIN 14 VCC = 5V TA = 25°C 360 50 270 40 5 4 180 3 2 90 0 –1 1 8.0 200 –10 0 1000 1 0 –1 1 10 100 FREQUENCY (MHz) 8 7 8.2 250 Gain and Phase Shift vs Frequency PHASE ( o ) GAIN (dB) 6 25°C +125°C 1 Gain and Phase Shift vs Frequency 7 85°C 1 0 1 –55°C 5 2 +85°C 1 RL = ∞ 450 BANDWIDTH (MHz) 5 8.4 NE5210 Bandwidth vs Temperature PIN 14 VCC = 5V 7 GAIN (dB) GAIN (dB) 6 8.6 AMBIENT TEMPERATURE (°C) 8 PIN 12 VCC = 5V +125°C 1000 Gain vs Frequency 8 7 10 100 FREQUENCY (MHz) POPULATION (%) 1 8 PIN 12 VCC = 5V RL = 50Ω PHASE ( o ) GAIN (dB) 6 5 8 PIN 12 VCC = 5V RL = 50Ω GAIN (dB) 7 NE5210 Differential Transresistance vs Temperature Gain vs Frequency DIFFERENTIAL TRANSRESISTANCE (kΩ ) Gain vs Frequency PIN 12 SINGLE-ENDED RL = 50Ω VCC = 5.0V TA = 25°C 30 20 10 0 0 10 100 FREQUENCY (MHz) 1000 223 255 287 319 351 FREQUENCY (MHz) 383 SD00325 1995 Apr 26 9 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) NE5210 Output Resistance vs Temperature NE5210 Output Resistance vs Temperature 16 16 PIN 14 ROUT 5.0V 14 5.0V PIN 12 ROUT 13 12 –10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE (°C) POWER SUPPLY REJECTION RATIO (dB) OUTPUT RESISTANCE (Ω ) VCC = 5.0V TA = 25°C 50 PIN 12 40 30 20 10 PIN 14 0 0.1 1 10 FREQUENCY (MHz) 5.0V 5.5V 13 PIN 14 OUTPUT REFERRED 16 4.5V 15 5.0V 5.5V 14 13 –10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE (°C) NE5210 Power Supply Rejection Ratio vs Temperature 80 60 4.5V 14 12 –10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE (°C) Output Resistance vs Frequency 70 15 100 200 40 39 38 Group Delay 10 VCC1 = VCC2 = 5.0V ∆VCC = ±0.1V DC TESTED OUTPUT REFERRED DELAY (ns) 15 17 PIN 12 OUTPUT REFERRED OUTPUT RESISTANCE (Ω ) VCC = 5.0V DC TESTED OUTPUT RESISTANCE (Ω ) OUTPUT RESISTANCE (Ω ) 17 NE5210 Output Resistance vs Temperature 37 36 8 VCC = 5V 6 TA = 25°C 4 2 0 35 34 33 –10 0 10 20 30 40 50 60 70 80 AMBIENT TEMPERATURE (°C) 0.1 20 40 60 80 100 120 140 160 180 200 FREQUENCY (MHz) Output Step Response VCC = 5V TA = 25°C 20mV/Div 0 2 4 6 8 10 (ns) 12 14 16 18 20 SD00326 1995 Apr 26 10 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 THEORY OF OPERATION Transimpedance amplifiers have been widely used as the preamplifier in fiber-optic receivers. The NE5210 is a wide bandwidth (typically 280MHz) 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 240µA. The NE5210 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 1. 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=3.6kΩ. 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 OUTPUT + A3 INPUT A1 A2 RF A4 OUTPUT – SD00327 Figure 1. NE5210 – Block Diagram BANDWIDTH CALCULATIONS The input stage, shown in Figure 3, 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. V OUT(diff) 2R F 2(3.6K) 7.2kW I IN 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 3.6K 51W R IN IN 71 I IN 1 A VOL The single-ended transresistance of the amplifier is typically 3.6kΩ. The simplified schematic in Figure 2 shows how an input current is converted to a differential output voltage. The amplifier has a 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 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. More exact calculations would yield a higher value of 60Ω. Thus CIN and RIN will form the dominant pole of the entire amplifier; f 3dB 2p 1 R IN C IN Assuming typical values for RF = 3.6kΩ, RIN = 60Ω, CIN = 7.5pF f 3dB 2p 1 354MHz 7.5pF 60 VCC1 VCC2 R3 R1 Q2 INPUT R13 Q4 Q11 + Q3 Q1 R12 Q12 Q15 R2 R14 GND1 Q16 R7 PHOTODIODE OUT– R15 + OUT+ VB2 R5 R4 GND2 SD00328 Figure 2. Transimpedance Amplifier 1995 Apr 26 11 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 For a given wavelength λ; (meters) Energy of one Photon = hc watt sec (Joule) l Where h=Planck’s Constant = 6.6 × 10-34 Joule sec. c = speed of light = 3 × 108 m/sec c / λ = optical frequency (Hz) No. of incident photons/sec= where P=optical incident power VCC IC1 R1 INPUT Q2 IB IIN R3 Q3 Q1 R2 VIN IF P No. of incident photons/sec = hs l VEQ3 where P = optical incident power RF P No. of generated electrons/sec = h @ hs l R4 where η = quantum efficiency SD00329 Figure 3. Shunt-Series Input Stage no. of generated electron hole paris no. of incident photons + The operating point of Q1, Figure 2, 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 cascode 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 = 60Ω then the total input capacitance, CIN = (1+7.5) pF which will lead to only a 12% bandwidth reduction. P hs N I + h @ @ e Amps (Coulombsń sec.) l where e = electron charge = 1.6 × 10-19 Coulombs h @e Responsivity R = hs Amp/watt l I + P@R Assuming a data rate of 400 Mbaud (Bandwidth, B=200MHz), the noise parameter Z may be calculated as:1 Z + NOISE 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: 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 3.5pA/√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 66nARMS in a 200MHz bandwidth. P avMIN + 12 hc B Z + 12 2.3 @ 10 *19 l 200 @ 10 6 2063 + 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 NE5210, at this input power is: I avMIN + qP avMIN l hc DYNAMIC RANGE CALCULATIONS The electrical dynamic range can be defined as the ratio of maximum input current to the peak noise current: *9 @ 10 *19 + 1139 @ 10 @ 1.6 2.3 @ 10 *19 = 792nA Electrical dynamic range, DE, in a 200MHz bandwidth assuming IINMAX = 240µA and a wideband noise of IEQ=66nARMS for an external source capacitance of CS = 1pF. D E + 20log Choosing the maximum peak overload current of IavMAX=240µA, the maximum mean optical power is: (Max. input current) (PK) (Peak noise current) (RMS) @ Ǹ 2 P avMAX + (240 @ 10 *6) + 20 log + 68dB (Ǹ 2 66 10 *9) hcI avMAX *19 + 2.3 @ 10 *19 240 @ 10 *6 l q 1.6 @ 10 Thus the optical dynamic range, DO is: In order to calculate the optical dynamic range the incident optical power must be considered. 1995 Apr 26 I EQ 66 @ 10 *9 + + 2063 qB (1.6 @ 10 *19)(200 @ 10 6) DO = PavMAX - PavMIN = -4.6 -(-29.4) = 24.8dB. 12 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 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. This represents the maximum limit attainable with the NE5210 operating at 200MHz bandwidth, with a half mark/half space digital transmission at 850nm wavelength. APPLICATION INFORMATION Package parasitics, particularly ground lead inductances and parasitic capacitances, can significantly degrade the frequency response. Since the NE5210 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, 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 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. Figure 4 depicts a 50Mb/s TTL fiber-optic receiver using the BPF31, 850nm LED, the NE5210 and the NE5214 post amplifier. +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 4. A 50Mb/s Fiber Optic Receiver 1995 Apr 26 13 SD00330 Philips Semiconductors Product specification Transimpedance amplifier (280MHz) NE5210 1 14 OUT (–) GND 2 13 2 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 5. NE5210 Bonding Diagram carriers, it is impossible to guarantee 100% functionality through this Die Sales Disclaimer process. There is no post waffle pack testing performed on Due to the limitations in testing high frequency and other parameters individual die. at the die level, and the fact that die electrical characteristics may shift after packaging, die electrical parameters are not specified and Since Philips Semiconductors has no control of third party die are not guaranteed to meet electrical characteristics (including procedures in the handling or packaging of die, Philips temperature range) as noted in this data sheet which is intended Semiconductors assumes no liability for device functionality or only to specify electrical characteristics for a packaged device. 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 1995 Apr 26 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. 14