EL5127, EL5227, EL5327, EL5427 ® Data Sheet 2.5MHz 4, 8, 10 & 12 Channel Rail-to-Rail Buffers The EL5127, EL5227, EL5327, and EL5427 are low power, high voltage rail-to-rail input/output buffers designed for use in reference voltage buffering applications in small LCD displays. They are available in quad (EL5127), octal (EL5227), 10-channel (EL5327), and 12-channel (EL5427) topologies. All buffers feature a -3dB bandwidth of 2.5MHz and operate from just 133µA per buffer. This family also features a continuous output drive capability of 30mA (sink and source). The quad channel EL5127 is available in the 10-pin MSOP package. The 8-channel EL5227 is available in both the 20pin TSSOP and 24-pin QFN packages, the 10-channel EL5327 in the 24-pin TSSOP and 24-pin QFN packages, and the 12-channel EL5427 in the 28-pin TSSOP and 32-pin QFN packages. All buffers are specified for operation over the full -40°C to +85°C temperature range. September 9, 2005 FN7111.2 Features • 2.5MHz -3dB bandwidth • Supply voltage = 4.5V to 16.5V • Low supply current (per buffer) = 133µA • High slew rate = 2.2V/µs • Rail-to-rail input/output swing • Ultra-small packages • Pb-free plus anneal available (RoHS compliant) Applications • TFT-LCD drive circuits • Electronic games • Touch-screen displays • Personal communication devices • Personal digital assistants (PDAs) • Portable instrumentation CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright © Intersil Americas Inc. 2004, 2005. All Rights Reserved. All other trademarks mentioned are the property of their respective owners. 1 EL5127, EL5227, EL5327, EL5427 Ordering Information PACKAGE TAPE & REEL PKG. DWG. # TAPE & REEL PKG. DWG. # EL5127CY 10-Pin MSOP - 24-Pin QFN (Pb-Free) - MDP0046 EL5127CY-T7 10-Pin MSOP EL5327CLZ-T7 (Note) 24-Pin QFN (Pb-Free) 7” MDP0046 EL5127CY-T13 MDP0043 EL5327CLZ-T13 (Note) 24-Pin QFN (Pb-Free) 13” MDP0046 - MDP0043 EL5327CR-T7 24-Pin TSSOP 7” MDP0044 10-Pin MSOP (Pb-Free) 7” MDP0043 EL5327CR-T13 24-Pin TSSOP 13” MDP0044 10-Pin MSOP (Pb-Free) 13” MDP0043 EL5327CRZ (Note) 24-Pin TSSOP (Pb-Free) - MDP0044 EL5227CL 24-Pin QFN - MDP0046 EL5327CRZ-T7 (Note) 24-Pin TSSOP (Pb-Free) 7” MDP0044 EL5227CL-T7 24-Pin QFN 7” MDP0046 EL5327CRZ-T13 24-Pin TSSOP (Note) (Pb-Free) 13” MDP0044 EL5227CL-T13 24-Pin QFN 13” MDP0046 EL5427CL 32-Pin QFN - MDP0046 EL5227CLZ (Note) 24-Pin QFN (Pb-Free) - MDP0046 EL5427CL-T7 32-Pin QFN 7” MDP0046 EL5227CLZ-T7 (Note) 24-Pin QFN (Pb-Free) 7” MDP0046 EL5427CL-T13 32-Pin QFN 13” MDP0046 EL5227CLZ-T13 (Note) 24-Pin QFN (Pb-Free) 13” MDP0046 EL5427CLZ (Note) 32-Pin QFN (Pb-Free) - MDP0046 EL5227CR 20-Pin TSSOP - MDP0044 EL5427CLZ-T7 (Note) 32-Pin QFN (Pb-Free) 7” MDP0046 EL5227CR-T7 20-Pin TSSOP 7” MDP0044 EL5427CLZ-T13 (Note) 32-Pin QFN (Pb-Free) 13” MDP0046 EL5227CR-T13 20-Pin TSSOP 13” MDP0044 EL5427CR 28-Pin TSSOP - MDP0044 EL5227CRZ (Note) 20-Pin TSSOP (Pb-Free) - MDP0044 EL5427CR-T7 28-Pin TSSOP 7” MDP0044 EL5227CRZ-T7 (Note) 20-Pin TSSOP (Pb-Free) 7” MDP0044 EL5427CR-T13 28-Pin TSSOP 13” MDP0044 EL5227CRZ-T13 20-Pin TSSOP (Note) (Pb-Free) 13” MDP0044 EL5427CRZ (Note) 28-Pin TSSOP (Pb-Free) - MDP0044 PART NUMBER PART NUMBER PACKAGE MDP0043 EL5327CLZ (Note) 7” MDP0043 10-Pin MSOP 13” EL5127CYZ (Note) 10-Pin MSOP (Pb-Free) EL5127CYZ-T7 (Note) EL5127CYZ-T13 (Note) EL5327CL 24-Pin QFN - MDP0046 EL5427CRZ-T7 (Note) 28-Pin TSSOP (Pb-Free) 7” MDP0044 EL5327CL-T7 24-Pin QFN 7” MDP0046 EL5427CRZ-T13 28-Pin TSSOP (Note) (Pb-Free) 13” MDP0044 EL5327CL-T13 24-Pin QFN 13” MDP0046 NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are 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-020. 2 EL5127, EL5227, EL5327, EL5427 Pinouts EL5127 (10-PIN MSOP) TOP VIEW EL5227 (20-PIN TSSOP) TOP VIEW EL5327 (24-PIN TSSOP) TOP VIEW EL5427 (28-PIN TSSOP) TOP VIEW VIN1 1 10 VOUT1 VIN1 1 20 VOUT1 VIN1 1 24 VOUT1 VIN1 1 28 VOUT1 VIN2 2 9 VOUT2 VIN2 2 19 VOUT2 VIN2 2 23 VOUT2 VIN2 2 27 VOUT2 8 VS- VIN3 3 18 VOUT3 VIN3 3 22 VOUT3 VIN3 3 26 VOUT3 VIN3 4 7 VOUT3 VIN4 4 17 VOUT4 VIN4 4 21 VOUT4 VIN4 4 25 VOUT4 VIN4 5 6 VOUT4 VS+ 5 16 VS- VIN5 5 20 VOUT5 VIN5 5 24 VOUT5 VS+ 6 15 VS- VS+ 6 19 VS- VIN6 6 23 VOUT6 VIN5 7 14 VOUT5 VS+ 7 18 VS- VS+ 7 22 VS- VIN6 8 13 VOUT6 VIN6 8 17 VOUT6 VS+ 8 21 VS- VIN7 9 12 VOUT7 VIN7 9 16 VOUT7 VIN7 9 20 VOUT7 VIN8 10 11 VOUT8 VIN8 10 15 VOUT8 VIN8 10 19 VOUT8 VIN9 11 14 VOUT9 VIN9 11 18 VOUT9 VIN10 12 13 VOUT10 VIN10 12 17 VOUT10 VIN11 13 16 VOUT11 VIN12 14 15 VOUT12 26 VOUT2 27 VOUT1 28 NC 31 VIN1 32 VIN2 20 VOUT2 21 VOUT1* 22 NC 23 VIN1* 24 VIN2 29 NC EL5427 (32-PIN QFN) TOP VIEW EL5227, EL5327 (24-PIN QFN) TOP VIEW 30 NC VS+ 3 VIN3 1 19 VOUT3 VIN3 1 25 VOUT3 VIN4 2 18 VOUT4 VIN4 2 24 VOUT4 17 VOUT5 VIN5 3 23 VOUT5 16 VS- VIN6 4 VIN5 3 THERMAL PAD VS+ 4 22 VOUT6 THERMAL PAD 19 VOUT8 VIN9 8 18 VOUT9 VIN10 9 17 VOUT10 3 VOUT11 16 21 VS- VOUT12 15 * NOT AVAILABLE IN EL5227 NC 14 VIN8 7 NC 13 13 VOUT8 NC 12 VIN8 7 VIN12 11 20 VOUT7 VIN11 10 VIN7 6 VOUT9 12 14 VOUT7 VOUT10* 11 VIN7 6 NC 10 VS+ 5 CVIN10* 9 15 VOUT6 VIN9 8 VIN6 5 EL5127, EL5227, EL5327, EL5427 Absolute Maximum Ratings (TA = 25°C) Supply Voltage Between VS+ and VS-. . . . . . . . . . . . . . . . . . . .+18V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . VS- -0.5V, VS +0.5V Maximum Continuous Output Current . . . . . . . . . . . . . . . . . . . 30mA ESD Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV Maximum Die Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . +125°C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Power Dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Curves Operating Temperature . . . . . . . . . . . . . . . . . . . . . . .-40°C to +85°C CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. 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: TJ = TC = TA VS+ = +5V, VS- = -5V, RL = 10kΩ, CL = 10pF to 0V, TA = 25°C, unless otherwise specified. Electrical Specifications PARAMETER DESCRIPTION CONDITIONS MIN TYP MAX UNIT 15 mV INPUT CHARACTERISTICS VOS Input Offset Voltage VCM = 0V 1 TCVOS Average Offset Voltage Drift (Note 1) 5 IB Input Bias Current VCM = 0V 2 RIN Input Impedance CIN Input Capacitance AV Voltage Gain -4.5V ≤ VOUT ≤ 4.5V µV/°C 50 nA 1 GΩ 1.35 pF 0.99 1.01 V/V -4.85 V OUTPUT CHARACTERISTICS VOL Output Swing Low IL = -5mA VOH Output Swing High IL = +5mA 4.85 4.95 IOUT (max) Max Output Current (Note 2) RL = 10Ω 100 ±120 55 80 -4.95 V 30 mA POWER SUPPLY PERFORMANCE PSRR Power Supply Rejection Ratio VS is moved from ±2.25V to ±7.75V IS Supply Current No load (EL5127) 0.7 0.9 mA No load (EL5227) 1.2 1.4 mA No load (EL5327) 1.4 2 mA No load (EL5427) 1.6 2.2 mA dB DYNAMIC PERFORMANCE SR Slew Rate (Note 3) -4.0V ≤ VOUT ≤ 4.0V, 20% to 80% tS Settling to +0.1% (AV = +1) BW CS 2.2 V/µs (AV = +1), VO = 2V step 900 ns -3dB Bandwidth RL = 10kΩ, CL = 10pF 2.5 MHz Channel Separation f = 100kHz 75 dB NOTES: 1. Measured over operating temperature range. 2. Instantaneous peak current. 3. Slew rate is measured on rising and falling edges. 4 0.9 EL5127, EL5227, EL5327, EL5427 VS+ = +5V, VS- = 0V, RL = 10kΩ, CL = 10pF to 2.5V, TA = 25°C, unless otherwise specified. Electrical Specifications PARAMETER DESCRIPTION CONDITION MIN TYP MAX UNIT 15 mV INPUT CHARACTERISTICS VOS Input Offset Voltage VCM = 2.5V 1 TCVOS Average Offset Voltage Drift (Note 1) 5 IB Input Bias Current VCM = 2.5V 2 RIN Input Impedance CIN Input Capacitance AV Voltage Gain 0.5V ≤ VOUT ≤ 4.5V µV/°C 50 nA 1 GΩ 1.35 pF 0.99 1.01 V/V 150 mV OUTPUT CHARACTERISTICS VOL Output Swing Low IL = -5mA VOH Output Swing High IL = +5mA 4.85 4.95 V IOUT (max) Output Current (Note 2) RL = 10Ω 100 ±120 mA 55 80 dB 80 POWER SUPPLY PERFORMANCE PSRR Power Supply Rejection Ratio VS is moved from 4.5V to 15.5V IS Supply Current No load (EL5127) 0.7 0.9 mA No load (EL5227) 1.1 1.35 mA No load (EL5327) 1.35 1.9 mA No load (EL5427) 1.5 2.05 mA DYNAMIC PERFORMANCE SR Slew Rate (Note 3) 1V ≤ VOUT ≤ 4V, 20% to 80% tS Settling to +0.1% (AV = +1) (AV = +1), VO = 2V step BW -3dB Bandwidth CS Channel Separation NOTES: 1. Measured over operating temperature range. 2. Instantaneous peak current. 3. Slew rate is measured on rising and falling edges. 5 0.9 1.5 V/µs 1000 ns RL = 10kΩ, CL = 10pF 2.5 MHz f = 5MHz 75 dB EL5127, EL5227, EL5327, EL5427 Electrical Specifications PARAMETER VS+ = +15V, VS- = 0V, RL = 10kΩ, CL = 10pF to 7.5V, TA = 25°C, unless otherwise specified. DESCRIPTION CONDITION MIN TYP MAX UNIT 18 mV INPUT CHARACTERISTICS VOS Input Offset Voltage VCM = 7.5V 1 TCVOS Average Offset Voltage Drift (Note 1) 5 IB Input Bias Current VCM = 7.5V 2 RIN Input Impedance CIN Input Capacitance AV Voltage Gain 0.5V ≤ VOUT ≤ 14.5V µV/°C 50 nA 1 GΩ 1.35 pF 0.99 1.01 V/V 150 mV OUTPUT CHARACTERISTICS VOL Output Swing Low IL = -5mA VOH Output Swing High IL = +5mA 14.85 14.95 V IOUT (max) Output Current (Note 2) RL = 10Ω 100 ±120 mA 55 80 dB 50 POWER SUPPLY PERFORMANCE PSRR Power Supply Rejection Ratio VS is moved from 4.5V to 15.5V IS Supply Current No load (EL5127) 0.75 0.95 mA No load (EL5227) 1.3 1.55 mA No load (EL5327) 1.5 2.1 mA No load (EL5427) 1.6 2.4 mA DYNAMIC PERFORMANCE SR Slew Rate (Note 3) 1V ≤ VOUT ≤ 14V, 20% to 80% tS Settling to +0.1% (AV = +1) BW CS 2.2 V/µs (AV = +1), VO = 2V step 900 ns -3dB Bandwidth RL = 10kΩ, CL = 10pF 2.5 MHz Channel Separation f = 5MHz 75 dB NOTES: 1. Measured over operating temperature range. 2. Instantaneous peak current. 3. Slew rate is measured on rising and falling edges. 6 0.9 EL5127, EL5227, EL5327, EL5427 Typical Performance Curves 20 CL=10pF VS=±5V 10 10kΩ NORMALIZED MAGNITUDE (dB) NORMALIZED MAGNITUDE (dB) 20 1kΩ 0 562Ω -10 150Ω -20 -30 1K 10K 100K 1M RL=10kΩ VS=±5V 10 47pF 12pF 0 1nF -10 100pF -20 -30 1K 10M FREQUENCY (Hz) TA=25°C VS=±5V 1200 800 400 0 1K 10K 10M 100K 1M 12 10 8 6 4 2 VS=±5V RL=10kΩ CL=12pF TA=25°C 0 10K 100K 1M 10M FREQUENCY (Hz) FREQUENCY (Hz) FIGURE 3. OUTPUT IMPEDANCE vs FREQUENCY FIGURE 4. MAXIMUM OUTPUT SWING vs FREQUENCY 300 0.12 0.1 100 THD + NOISE (%) VOLTAGE NOISE (nV/√Hz) 1M FIGURE 2. FREQUENCY RESPONSE FOR VARIOUS CL MAXIMUM OUTPUT SWING (VP-P) OUTPUT IMPEDANCE (Ω) 1600 100K FREQUENCY (Hz) FIGURE 1. FREQEUNCY RESPONSE FOR VARIOUS RL 2000 10K 0.06 0.04 0.02 10 1K 0.08 10K 100K 1M 10M 100M FREQUENCY (Hz) FIGURE 5. INPUT VOLTAGE NOISE SPECTRAL DENSITY vs FREQUENCY 7 0 1K 10K 100K FREQUENCY (Hz) FIGURE 6. TOTAL HARMONIC DISTORTION + NOISE vs FREQUENCY EL5127, EL5227, EL5327, EL5427 Typical Performance Curves 60 50 40 12 10 8 6 30 4 20 2 FIGURE 7. SMALL SIGNAL OVERSHOOT vs LOAD CAPACITANCE 2.5 2 1.5 -35 -15 5 25 45 65 4.93 1.0045 -35 -15 5 25 45 65 85 VS=±5V 1.004 VOLTAGE GAIN (V/V) OUTPUT LOW VOLTAGE (V) 10 4.935 FIGURE 10. OUTPUT HIGH VOLTAGE vs TEMPERATURE VS=±5V IOUT=-5mA -4.946 -4.95 -4.954 -4.958 8 4.94 TEMPERATURE (°C) FIGURE 9. INPUT BIAS CURRENT vs TEMPERATURE -4.942 6 4.945 4.925 85 VS=±5V IOUT=5mA 4.95 TEMPERATURE (°C) -4.938 4 4.955 VS=±5V OUTPUT HIGH VOLTAGE (V) INPUT BIAS CURRENT (nA) FIGURE 8. INPUT OFFSET VOLTAGE DISTRIBUTION 3 1 2 INPUT OFFSET VOLTAGE (mV) CAPACITANCE (pF) 3.5 0 1K -2 100 -4 0 0 10 -6 70 14 -10 OVERSHOOT (%) 80 16 -8 90 18 VS=±5V RL=10kΩ VIN=±50mV TA=25°C % OF BUFFERS 100 1.0035 1.003 1.0025 1.002 1.0015 -35 -15 5 25 45 65 85 TEMPERATURE (°C) FIGURE 11. OUTPUT LOW VOLTAGE vs TEMPERATURE 8 1.001 -35 -15 5 25 45 65 85 TEMPERATURE (°C) FIGURE 12. VOLTAGE GAIN vs TEMPERATURE EL5127, EL5227, EL5327, EL5427 Typical Performance Curves 0.185 SUPPLY CURRENT (mA) SLEW RATE (V/µs) 2.255 2.245 2.235 2.225 VS=±5V 2.215 -40 -20 0 20 40 0.18 0.175 0.17 0.165 0.16 80 60 VS=±5V -35 -15 TEMPERATURE (°C) SUPPLY CURRENT (mA) 25 45 65 85 TEMPERATURE (°C) FIGURE 13. SLEW RATE vs TEMPERATURE 0.195 5 FIGURE 14. SUPPLY CURRENT PER CHANNEL vs TEMPERATURE TA=25°C 0.19 0.185 0.18 1V/DIV 0.175 0.17 0.165 4 6 8 10 12 14 16 18 4µs/DIV SUPPLY VOLTAGE (V) FIGURE 15. SUPPLY CURRENT PER CHANNEL vs SUPPLY VOLTAGE FIGURE 16. LARGE SIGNAL TRANSIENT RESPONSE JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD POWER DISSIPATION (W) 3 20mV/DIV 2.5 2.703W QFN32 θJA=35°C/W 2 QFN24 θJA=37°C/W 1.5 1 870mW 0.5 0 1µs/DIV 2.857W MSOP10 θJA=115°C/W 0 25 50 75 85 100 125 150 AMBIENT TEMPERATURE (°C) FIGURE 17. SMALL SIGNAL TRANSIENT RESPONSE 9 FIGURE 18. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE EL5127, EL5227, EL5327, EL5427 Typical Performance Curves JEDEC JESD51-7 HIGH EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 0.8 1.333W 1.2 1.176W 1 1.111W POWER DISSIPATION (W) POWER DISSIPATION (W) 1.4 TSSOP24 θJA=85°C/W 0.8 TSSOP28 θJA=75°C/W 0.6 TSSOP20 θJA=90°C/W 0.4 0.2 0 0 25 50 75 85 100 JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 758mW 0.7 714mW QFN32 θJA=132°C/W 0.6 0.5 486mW 0.4 0.3 MSOP10 θJA=206°C/W 0.2 0.1 0 125 0 25 50 75 85 100 125 150 AMBIENT TEMPERATURE (°C) AMBIENT TEMPERATURE (°C) FIGURE 19. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE 0.9 POWER DISSIPATION (W) QFN24 θJA=140°C/W FIGURE 20. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE JEDEC JESD51-3 LOW EFFECTIVE THERMAL CONDUCTIVITY TEST BOARD 833mW 0.8 0.7 781mW 714mW 0.6 TSSOP28 θJA=120°C/W 0.5 TSSOP24 θJA=128°C/W 0.4 0.3 0.2 TSSOP20 θJA=140°C/W 0.1 0 0 25 50 75 85 100 125 AMBIENT TEMPERATURE (°C) FIGURE 21. PACKAGE POWER DISSIPATION vs AMBIENT TEMPERATURE Applications Information Product Description The EL5127, EL5227, EL5327, and EL5427 unity gain buffers are fabricated using a high voltage CMOS process. It exhibits rail-to-rail input and output capability and has low power consumption (120µA per buffer). These features make the EL5127, EL5227, EL5327, and EL5427 ideal for a wide range of general-purpose applications. When driving a load of 10kΩ and 12pF, the EL5127, EL5227, EL5327, and EL5427 have a -3dB bandwidth of 2.5MHz and exhibits 2.2V/µs slew rate. Operating Voltage, Input, and Output The EL5127, EL5227, EL5327, and EL5427 are specified with a single nominal supply voltage from 5V to 15V or a split supply with its total range from 5V to 15V. Correct operation is guaranteed for a supply range of 4.5V to 16.5V. Most EL5127, EL5227, EL5327, and EL5427 specifications are stable over both the full supply range and operating 10 temperatures of -40°C to +85°C. Parameter variations with operating voltage and/or temperature are shown in the typical performance curves. The output swings of the EL5127, EL5227, EL5327, and EL5427 typically extend to within 80mV of positive and negative supply rails with load currents of 5mA. Decreasing load currents will extend the output voltage range even closer to the supply rails. Figure 22 shows the input and output waveforms for the device. Operation is from ±5V supply with a 10kΩ load connected to GND. The input is a 10VP-P sinusoid. The output voltage is approximately 9.985VP-P. EL5127, EL5227, EL5327, EL5427 5V application to determine if load conditions need to be modified for the buffer to remain in the safe operating area. 10µs VS=±5V TA=25°C VIN=10VP-P 5V OUTPUT INPUT The maximum power dissipation allowed in a package is determined according to: FIGURE 22. OPERATION WITH RAIL-TO-RAIL INPUT AND OUTPUT Short Circuit Current Limit T JMAX - T AMAX P DMAX = -------------------------------------------Θ JA where: TJMAX = Maximum junction temperature TAMAX = Maximum ambient temperature θJA = Thermal resistance of the package The EL5127, EL5227, EL5327, and EL5427 will limit the short circuit current to ±120mA if the output is directly shorted to the positive or the negative supply. If an output is shorted indefinitely, the power dissipation could easily increase such that the device may be damaged. Maximum reliability is maintained if the output continuous current never exceeds ±30mA. This limit is set by the design of the internal metal interconnects. 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 loads, or: Output Phase Reversal when sourcing, and: The EL5127, EL5227, EL5327, and EL5427 are immune to phase reversal as long as the input voltage is limited from VS- -0.5V to VS+ +0.5V. Figure 23 shows a photo of the output of the device with the input voltage driven beyond the supply rails. Although the device's output will not change phase, the input's overvoltage should be avoided. If an input voltage exceeds supply voltage by more than 0.6V, electrostatic protection diodes placed in the input stage of the device begin to conduct and overvoltage damage could occur. P DMAX = Σi [ V S × I SMAX + ( V OUT i - V S - ) × I LOAD i ] 1V 10µs PDMAX = Maximum power dissipation in the package P DMAX = Σi [ V S × I SMAX + ( V S + - V OUT i ) × I LOAD i ] when sinking. where: i = 1 to Total number of buffers VS = Total supply voltage ISMAX = Maximum quiescent current per channel VOUTi = Maximum output voltage of the application ILOADi = Load current VS=±2.5V TA=25°C VIN=6VP-P 1V FIGURE 23. OPERATION WITH BEYOND-THE-RAILS INPUT If we set the two PDMAX equations equal to each other, we can solve for RLOADi to avoid device overheat. The package power dissipation curves provide a convenient way to see if the device will overheat. The maximum safe power dissipation can be found graphically, based on the package type and the ambient temperature. By using the previous equation, it is a simple matter to see if PDMAX exceeds the device's power derating curves. Power Dissipation Unused Buffers With the high-output drive capability of the EL5127, EL5227, EL5327, and EL5427 buffer, it is possible to exceed the 125°C “absolute-maximum junction temperature” under certain load current conditions. Therefore, it is important to calculate the maximum junction temperature for the It is recommended that any unused buffer have the input tied to the ground plane. 11 EL5127, EL5227, EL5327, EL5427 Driving Capacitive Loads The EL5127, EL5227, EL5327, and EL5427 can drive a wide range of capacitive loads. As load capacitance increases, however, the -3dB bandwidth of the device will decrease and the peaking increase. The buffers drive 10pF loads in parallel with 10kΩ with just 1.5dB of peaking, and 100pF with 6.4dB of peaking. If less peaking is desired in these applications, a small series resistor (usually between 5Ω and 50Ω) can be placed in series with the output. However, this will obviously reduce the gain slightly. Another method of reducing peaking is to add a “snubber” circuit at the output. A snubber is a shunt load consisting of a resistor in series with a capacitor. Values of 150Ω and 10nF are typical. The advantage of a snubber is that it does not draw any DC load current or reduce the gain. Power Supply Bypassing and Printed Circuit Board Layout As with any high frequency device, good printed circuit board layout is necessary for optimum performance. Ground plane construction is highly recommended, lead lengths should be as short as possible, and the power supply pins must be well bypassed to reduce the risk of oscillation. For normal single supply operation, where the VS- pin is connected to ground, a 0.1µF ceramic capacitor should be placed from VS+ pin to VS- pin. A 4.7µF tantalum capacitor should then be connected from VS+ pin to ground. One 4.7µF capacitor may be used for multiple devices. This same capacitor combination should be placed at each supply pin to ground if split supplies are to be used. All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality 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 www.intersil.com 12