250MHz Differential Twisted-Pair Driver

Transcription

1 5MHz Differential Twisted-Pair Driver EL576 The EL576 is a high bandwidth amplifier with an output in differential form. It is primarily targeted for applications such as driving twisted-pair lines or any application where common mode injection is likely to occur. The input signal can be in either single-ended or differential form but the output is always in differential form. On the EL576, two feedback inputs provide the user with the ability to set the device gain (stable at minimum gain of one). The output common mode level is set by the reference pin (), which has a -db bandwidth of over 5MHz. Generally, this pin is grounded but it can be tied to any voltage reference. Both outputs (OUT+, OUT-) are short-circuit protected to withstand temporary overload condition. The EL576 is available in the Ld MSOP package and is specified for operation over the full - C to +85 C temperature range. See also EL57 (EL576 in 8 Ld MSOP). Features Fully differential inputs, outputs, and feedback 5MHz db bandwidth 8V/µs slew rate Low distortion at MHz Single 5V or dual ±5V supplies ma maximum output current Low power - 8mA typical supply current Pb-free (RoHS compliant) Applications Twisted-pair drivers Differential line drivers VGA over twisted-pair ADSL/HDSL drivers Single-ended to differential amplification Transmission of analog signals in a noisy environment Pin Configuration EL576 ( LD MSOP) TOP VIEW FBP OUT+ IN+ 9 VS VS+ IN- 7 EN FBN 5 6 OUT- August 8, FN7.5 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures INTERSIL or Copyright Intersil Americas Inc. -5, 7,,. All Rights Reserved Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners.

2 EL576 Pin Descriptions PIN NUMBER PIN NAME PIN DESCRIPTION FBP Non-inverting feedback input; resistor R F must be connected from this pin to V OUT IN+ Non-inverting input Output common-mode control; the common-mode voltage of V OUT will follow the voltage on this pin IN- Inverting input 5 FBN Inverting feedback input; resistor R F must be connected from this pin to V OUT 6 OUT- Inverting output 7 EN Enabled when this pin is floating or the applied voltage V S VS+ Positive supply 9 VS- Negative supply OUT+ Non-inverting output Ordering Information PART NUMBER (Notes,, ) PART MARKING PACKAGE (Pb-free) PKG. DWG. # EL576IYZ BAAAC Ld MSOP (.mm) M.8A NOTES:. Add -T* suffix for tape and reel. Please refer to TB7 for details on reel specifications.. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and % matte tin plate plus anneal (e termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-.. For Moisture Sensitivity Level (MSL), please see device information page for EL576. For more information on MSL please see tech brief TB6. FN7.5 August 8,

3 EL576 Absolute Maximum Ratings (T A = +5 C) Supply Voltage (V S + to V S -) V Supply Voltage Rate-of-rise (dv/dt) V/µs Input Voltage (IN+, IN- to V S +, V S -) V S - -.V to V S + +.V Differential Input Voltage (IN+ to IN-) ±.8V Maximum Output Current ±6mA Thermal Information Thermal Resistance (Typical) θ JA ( C/W) θ JC ( C/W) Ld MSOP (Note ) N/A Operating Junction Temperature C Ambient Operating Temperature C to +85 C Storage Temperature Range C to +5 C Power Dissipation See Curves Pb-Free Reflow Profile see link below CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. NOTE:. θ JA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB79 for details. IMPORTANT NOTE: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: T J = T C = T A Electrical Specifications V S + = +5V, V S - = -5V, T A = +5 C, V IN = V, R LD = kω, R F =, R G = OPEN, C LD =.7pF, Unless Otherwise Specified. PARAMETER DESCRIPTION CONDITIONS AC PERFORMANCE MIN (Note 5) TYP MAX (Note 5) BW -db Bandwidth A V =, C LD =.7pF 5 MHz A V =, R F = 5, C LD =.7pF 6 MHz A V =, R F = 5, C LD =.7pF MHz BW ±.db Bandwidth A V =, C LD =.7pF 5 MHz SR Slew Rate - Rise V OUT = V P-P, % to 8% 6 8 V/µs Slew Rate - Fall V OUT = V P-P, % to 8% 5 7 V/µs t STL Settling Time to.% V OUT = V P-P ns t OVR Output Overdrive Recovery Time ns GBWP Gain Bandwidth Product MHz V BW (-db) V -db Bandwidth A V =, C LD =.7pF 5 MHz V SR+ V Slew Rate - Rise V OUT = V P-P, % to 8% 9 V/µs V SR- V Slew Rate - Fall V OUT = V P-P, % to 8% 5 V/µs V N Input Voltage Noise at khz 6 nv/ Hz I N Input Current Noise at khz pa/ Hz HD Second Harmonic Distortion V OUT = V P-P, 5MHz -9 dbc V OUT = V P-P, MHz -9 dbc HD Third Harmonic Distortion V OUT = V P-P, 5MHz -77 dbc V OUT = V P-P, MHz -75 dbc dg Differential Gain at.58mhz R L = Ω, A V =. % dθ Differential Phase at.58mhz R L = Ω, A V =.5 INPUT CHARACTERISTICS V OS Input Referred Offset Voltage ±.5 ±5 mv I IN Input Bias Current (V IN +, V IN -) µa I Input Bias Current (V ).5. µa R IN Differential Input Resistance kω C IN Differential Input Capacitance pf DMIR Differential Mode Input Range ±. ±. ±.5 V UNIT FN7.5 August 8,

4 EL576 Electrical Specifications V S + = +5V, V S - = -5V, T A = +5 C, V IN = V, R LD = kω, R F =, R G = OPEN, C LD =.7pF, Unless Otherwise Specified. (Continued) PARAMETER DESCRIPTION CONDITIONS CMIR+ Common Mode Positive Input Range at V IN +, V IN -.. V CMIR- Common Mode Negative Input Range at V IN +, V IN V V IN + Positive Reference Input Voltage Range V IN + = V IN - = V.5.8 V V IN - Negative Reference Input Voltage Range V IN + = V IN - = V -. - V V OS Output Offset Relative to V ±6 ± mv CMRR Input Common Mode Rejection Ratio V IN = ±.5V 65 8 db Gain Gain Accuracy V IN = V OUTPUT CHARACTERISTICS V OUT Positive Output Swing R L = 5Ω to GND.6.9 V Negative Output Swing V I OUT (Max) Maximum Source Output Current R L = Ω, 5 5 ma Maximum Sink Output Current V IN + =.V, V IN - = -.V, V = - - ma R OUT Output Impedance mω SUPPLY MIN (Note 5) V SUPPLY Supply Operating Range V S + to V S -.75 V I S(ON) Power Supply Current - Per Channel ma I S(OFF) + Positive Power Supply Current - Disabled EN pin tied to.8v 8 µa I S(OFF) - Negative Power Supply Current - Disabled - - µa PSRR Power Supply Rejection Ratio V S from ±.5V to ±5.5V 7 8 db ENABLE t EN Enable Time 5 ns t DS Disable Time.95 µs V IH EN Pin Voltage for Power-Up V S V V IL EN Pin Voltage for Shutdown V S V I IH-EN EN Pin Input Current High At V EN = 5V 6 µa I IL-EN EN Pin Input Current Low At V EN = V µa NOTE: 5. Parameters with MIN and/or MAX limits are % tested at +5 C, unless otherwise specified. Temperature limits established by characterization and are not production tested. TYP MAX (Note 5) UNIT FN7.5 August 8,

5 EL576 Connection Diagram R F V R S 5Ω FBP Ω OUT+ OUT+ INP R S 5Ω R S 5Ω R G OPEN IN+ IN- VS- VS+ EN V +5V R LD kω EN 5 FBN OUT- 6 INN- OUT- R F Ω Typical Performance Curves MAGNITUDE (db) A V =, R LD = kω, C LD =.7pF V OP-P = mv V OP-P = V P-P M M M G FIGURE. FREQUENCY RESPONSE NORMALIZED MAGNITUDE (db) R LD = kω, C LD =.7pF - A V = - - A V = 5 A V = - A V = -5-6 M M M G FIGURE. FREQUENCY RESPONSE FOR VARIOUS GAIN NORMALIZED GAIN (db) A V =, C LD =.7pF R LD = kω R LD = 5Ω R LD = Ω -6 M M M G FIGURE. FREQUENCY RESPONSE vs R LD MAGNITUDE (db) A V =, R LD = kω 5 C LD = 56pF C LD = pf C LD = pf - C LD = 9pF - C LD =.7pF M M M G FIGURE. FREQUENCY RESPONSE vs C LD 5 FN7.5 August 8,

6 EL576 Typical Performance Curves (Continued) A V =, R LD = kω, C LD =.7pF A V =, R F = kω, C LD =.7pF 9 9 NORMALIZED GAIN (db) R F = Ω R F = kω R F = 5Ω NORMALIZED GAIN (db) R LD = Ω R LD = kω R LD = 5Ω M M M M M M M M FIGURE 5. FREQUENCY RESPONSE FIGURE 6. FREQUENCY RESPONSE vs R LD 5 MAGNITUDE (db) - - IMPEDANCE (Ω) k M M M. k k M M M FIGURE 7. FREQUENCY RESPONSE - V FIGURE 8. OUTPUT IMPEDANCE vs FREQUENCY PSRR (db) PSRR PSRR k k k M M M FIGURE 9. PSRR vs FREQUENCY CMRR (db) k M M M G FIGURE. CMRR vs FREQUENCY 6 FN7.5 August 8,

7 EL576 Typical Performance Curves (Continued) VOLTAGE NOISE (nv/ Hz), CURRENT NOISE (pa/ Hz) k E N I N k k k M M FIGURE. VOLTAGE AND CURRENT NOISE vs FREQUENCY DISTORTION (db) V S = ±5V, A V =, R LD = kω HD (f = MHz) HD (f = 5MHz) HD (f = MHz) V OP-P, DM (V) HD (f = 5MHz) FIGURE. HARMONIC DISTORTION vs DIFFERENTIAL OUTPUT VOLTAGE V S = ±5V, A V =, R LD = kω -5 V S = ±5V, A V =, V OP-P, DM = V DISTORTION (db) HD (f = 5MHz) HD (f = MHz) HD (f = 5MHz) HD (f = MHz) DISTORTION (db) HD (f = MHz) HD (f = MHz) HD (f = 5MHz) HD (f = 5MHz) V OP-P, DM (V) R LD (Ω) FIGURE. HARMONIC DISTORTION vs DIFFERENTIAL OUTPUT VOLTAGE FIGURE. HARMONIC DISTORTION vs R LD - V S = ±5V, A V =, V OP-P, DM = V - V S = ±5V, R LD = kω, V OP-P, DM = V for A V =, V OP-P, DM = V for A V = -5 HD (f = MHz) -5 HD (A V = ) DISTORTION (db) HD (f = 5MHz) HD (f = MHz) DISTORTION (db) HD (A V = ) HD (A V = ) HD (A V = ) -9 HD (f = 5MHz) R LD (Ω) FIGURE 5. HARMONIC DISTORTION vs R LD FREQUENCY (MHz) FIGURE 6. HARMONIC DISTORTION vs FREQUENCY 7 FN7.5 August 8,

8 EL576 Typical Performance Curves (Continued) 5mV/DIV.5V/DIV ns/div FIGURE 7. SMALL SIGNAL TRANSIENT RESPONSE ns/div FIGURE 8. LARGE SIGNAL TRANSIENT RESPONSE M = ns, CH = 5mV/DIV, CH = 5V/DIV M = ns, CH = 5mV/DIV, CH = 5V/DIV CH CH CH CH ns/div FIGURE 9. ENABLED RESPONSE ns/div FIGURE. DISABLED RESPONSE JEDEC JESD5- LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD.6 JEDEC JESD5-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD. POWER DISSIPATION (W) mW MSOP8/ θ JA = +6 C/W POWER DISSIPATION (W) mW MSOP8/ θ JA = +5 C/W AMBIENT TEMPERATURE ( C) AMBIENT TEMPERATURE ( C) FIGURE. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE FIGURE. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE 8 FN7.5 August 8,

9 EL576 Simplified Schematic V S + R R R R R 7 R 8 IN+ IN- FBP FBN V B OUT+ R CD R CD C C V B OUT- R 9 R C C R 5 R 6 V S - Description of Operation and Application Information Product Description The EL576 is a wide bandwidth, low power and single/differential ended to differential output amplifier. It can be used as single/differential ended to differential converter. The EL576 is internally compensated for closed loop gain of + or greater. Connected in gain of and driving a kω differential load, the EL576 has a -db bandwidth of 5MHz. Driving a Ω differential load at gain of, the bandwidth is about MHz. The EL576 is available with a power-down feature to reduce the power while the amplifier is disabled. Input, Output, and Supply Voltage Range The EL576 has been designed to operate with a single supply voltage of 5V to V or a split supplies with its total voltage from 5V to V. The amplifier has an input common mode voltage range from -.5V to.v for ±5V supply. The differential mode input range (DMIR) between the two inputs is from -.V to +.V. The input voltage range at the pin is from -.V to.8v. If the input common mode or differential mode signal is outside the above-specified ranges, it will cause the output signal to become distorted. The output of the EL576 can swing from -.8V to +.9V at kω differential load at ±5V supply. As the load resistance becomes lower, the output swing is reduced. Differential and Common Mode Gain Settings The voltage applied at pin can set the output common mode voltage and the gain is one. The differential gain is set by the R F and R G network. The gain setting for EL576 is expressed in Equation : V ODM ( V IN + V IN - ) R F = R G V OCM = V (EQ. ) R F + R F V ODM = V IN R G Where: R F = R F = R F V IN + V IN - V R G FBP IN+ IN- FBN R F R F FIGURE. V O + V O - Choice of Feedback Resistor and Gain Bandwidth Product For applications that require a gain of +, no feedback resistor is required. Just short the OUT+ pin to the FBP pin and the OUT- pin to the FBN pin. For gains greater than +, the feedback resistor forms a pole with the parasitic capacitance at the inverting input. As this pole becomes smaller, the amplifier's phase margin is reduced. This causes ringing in the time domain and peaking in the frequency domain. Therefore, R F has some maximum value that should not be exceeded for optimum performance. If a large value of R F must be used, a small capacitor in the few Pico farad range in parallel with R F can help to reduce the ringing and peaking at the expense of reducing the bandwidth. 9 FN7.5 August 8,

10 EL576 The bandwidth of the EL576 depends on the load and the feedback network. R F and R G appear in parallel with the load for gains other than +. As this combination gets smaller, the bandwidth falls off. Consequently, R F also has a minimum value that should not be exceeded for optimum bandwidth performance. For gain of +, R F = is optimum. For the gains other than +, optimum response is obtained with R F between 5Ω to kω. The EL576 has a gain bandwidth product of MHz for R LD =kω. For gains 5, its bandwidth can be predicted by Equation : Gain BW = MHz (EQ. ) Driving Capacitive Loads and Cables The EL576 can drive a 5pF differential capacitor in parallel with kω differential load with less than 5dB of peaking at a gain of +. If less peaking is desired in applications, a small series resistor (usually between 5Ω to 5Ω) can be placed in series with each output to eliminate most peaking. However, this will reduce the gain slightly. If the gain setting is greater than, the gain resistor R G can then be chosen to make up for any gain loss, which may be created by the additional series resistor at the output. When used as a cable driver, double termination is always recommended for reflection-free performance. For those applications, a back-termination series resistor at the amplifier's output will isolate the amplifier from the cable and allow extensive capacitive drive. However, other applications may have high capacitive loads without a back-termination resistor. Again, a small series resistor at the output can help to reduce peaking. Disable/Power-Down The EL576 can be disabled and its outputs placed in a high impedance state. The turn-off time is about.95µs and the turnon time is about 5ns. When disabled, the amplifier's supply current is reduced to.7µa for I S + and µa for I S - typically, thereby effectively eliminating the power consumption. The amplifier's power-down can be controlled by standard CMOS signal levels at the ENABLE pin. The applied logic signal is relative to V S + pin. Letting the EN pin float or applying a signal that is less than.5v below V S + will enable the amplifier. The amplifier will be disabled when the signal at the EN pin is above V S + -.5V. Output Drive Capability The EL576 has internal short circuit protection. Its typical short circuit current is ±ma for EL576. If the output is shorted indefinitely, the power dissipation could easily increase such that the part will be destroyed. Maximum reliability is maintained if the output current never exceeds ±ma. This limit is set by the design of the internal metal interconnect. Power Dissipation With the high output drive capability of the EL576, it is possible to exceed the +5 C absolute maximum junction temperature under certain load current conditions. Therefore, it is important to calculate the maximum junction temperature for the application to determine if the load conditions or package types need to be modified for the amplifier to remain in the safe operating area. The maximum power dissipation allowed in a package is determined according to Equation : T JMAX T AMAX PD MAX = (EQ. ) Θ JA Where: T JMAX = Maximum junction temperature T AMAX = Maximum ambient temperature θ JA = Thermal resistance of the package The maximum power dissipation actually produced by an IC is the total quiescent supply current times the total power supply voltage, plus the power in the IC due to the load, or as expressed in Equation : PD i V STOT I SMAX ( V STOT ΔV O ) ΔV O = R LD Where: V STOT = Total supply voltage = V S + - V S - I SMAX = Maximum quiescent supply current per channel ΔV O = Maximum differential output voltage of the application R LD = Differential load resistance I LOAD = Load current i = Number of channels (EQ. ) By setting the two PD MAX equations equal to each other, we can solve the output current and R LD to avoid the device overheat. Power Supply Bypassing and Printed Circuit Board Layout As with any high frequency device, a good printed circuit board layout is necessary for optimum performance. Lead lengths should be as short as possible. The power supply pin must be well bypassed to reduce the risk of oscillation. For normal single supply operation, where the V S - pin is connected to the ground plane, a single.7µf tantalum capacitor in parallel with a.µf ceramic capacitor from V S + to GND will suffice. This same capacitor combination should be placed at each supply pin to ground if split supplies are to be used. In this case, the V S - pin becomes the negative supply rail. For good AC performance, parasitic capacitance should be kept to a minimum. Use of wire-wound resistors should be avoided because of their additional series inductance. Use of sockets should also be avoided if possible. Sockets add parasitic inductance and capacitance that can result in compromised performance. Minimizing parasitic capacitance at the amplifier's inverting input pin is very important. The feedback resistor should be placed very close to the inverting input pin. Strip line design techniques are recommended for the signal traces. As the signal is transmitted through a cable, the high frequency signal will be attenuated. One way to compensate this loss is to boost the high frequency gain at the receiver side. FN7.5 August 8,

11 EL576 Typical Applications R F R T R G EL TWISTED-PAIR Z O = Ω IN+ FBP IN+ IN- FBN IN- EL57 V O R F R FR R GR FIGURE. TWISTED-PAIR CABLE RECEIVER R F GAIN (db) FBP R T 75 R GC R G I N + I N - V O + C L FBN V O - R F f L f H FREQUENCY DC Gain R F = R G f L πr G C C R F ( HF)Gain = R G R GC f H πr GC C C FIGURE 5. TRANSMIT EQUALIZER For additional products, see Intersil products are manufactured, assembled and tested utilizing ISO9 quality systems as noted in the quality certifications found at Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see FN7.5 August 8,

12 EL576 Package Outline Drawing M.8A (JEDEC MO-87-BA) LEAD MINI SMALL OUTLINE PLASTIC PACKAGE (MSOP) Rev, 9/9. ±. A.5 C A B DETAIL "X". Max. ±..9 ±.5 SIDE VIEW.8 ±.5 PIN# ID B.5 BSC.95 BSC TOP VIEW Gauge H.86 ±.9 Plane.5 C. +.7/ CAB SEATING PLANE. ±.5. C.55 ±.5 DETAIL "X" ± SIDE VIEW NOTES:. Dimensions are in millimeters.. Dimensioning and tolerancing conform to AMSE Y.5m Plastic or metal protrusions of.5mm max per side are not included. Plastic interlead protrusions of.5mm max per side are not included. Dimensions D and E are measured at Datum Plane H. TYPICAL RECOMMENDED LAND PATTERN 6. This replaces existing drawing # MDP MSOPL. FN7.5 August 8,

13 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Intersil: EL576IYZ EL576IYZ-T EL576IYZ-T7