Dual 12MHz Rail-to-Rail Input-Output Buffer Features General Description • • • • The EL5221C is a dual, low power, high voltage rail-to-rail input-output buffer. Operating on supplies ranging from 5V to 15V, while consuming only 500µA per channel, the EL5221C has a bandwidth of 12MHz (-3dB). The EL5221C also provides rail-to-rail input and output ability, giving the maximum dynamic range at any supply voltage. Applications The EL5221C also features fast slewing and settling times, as well as a high output drive capability of 30mA (sink and source). These features make the EL5221C ideal for use as voltage reference buffers in Thin Film Transistor Liquid Crystal Displays (TFT-LCD). Other applications include battery power, portable devices, and anywhere low power consumption is important. 12MHz -3dB bandwidth Unity gain buffer Supply voltage = 4.5V to 16.5V Low supply current (per buffer) = 500µA • High slew rate = 10V/µs • Rail-to-rail operation • • • • • • • • • • TFT-LCD drive circuits Electronics notebooks Electronics games Personal communication devices Personal Digital Assistants (PDA) Portable instrumentation Wireless LANs Office automation Active filters ADC/DAC buffer EL5221C EL5221C The EL5221C is available in space-saving SOT23-6 and MSOP-8 packages and operates over a temperature range of -40°C to +85°C. Connection Diagrams Ordering Information Package Tape & Reel Outline # EL5221CW-T7 Part No. SOT23-6 7” MDP0038 EL5221CW-T13 SOT23-6 13” MDP0038 EL5221CY-T7 MSOP-8 7” MDP0043 EL5221CY-T13 MSOP-8 13” MDP0043 6 VOUTA VINA 1 5 VS+ VS- 2 4 VOUTB VINB 3 SOT23-6 VOUTA 1 8 VS+ 7 VOUTB VINA 3 6 NC VS- 4 5 VINB MSOP-8 Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation. © 2000 Elantec Semiconductor, Inc. November 7, 2000 NC 2 EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Absolute Maximum Ratings (T A = 25°C) Values beyond absolute maximum ratings can cause the device to be prematurely damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied +18V Supply Voltage between VS+ and VSInput Voltage VS- - 0.5V, VS+ +0.5V Maximum Continuous Output Current 30mA Maximum Die Temperature Storage Temperature Operating Temperature Power Dissipation ESD Voltage +125°C -65°C to +150°C -40°C to +85°C See Curves 2kV 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 Electrical Characteristics VS+ = +5V, VS- = -5V, RL = 10kΩ and CL = 10pF to 0V, TA = 25°C unless otherwise specified. Parameter Description Condition Min Typ Max 12 Unit Input Characteristics VOS Input Offset Voltage VCM = 0V 2 TCVOS Average Offset Voltage Drift  5 VCM = 0V 2 IB Input Bias Current RIN Input Impedance CIN Input Capacitance AV Voltage Gain 50 1 0.995 nA GΩ 1.35 -4.5V ≤ VOUT ≤ 4.5V mV µV/°C pF 1.005 V/V -4.85 V Output Characteristics VOL Output Swing Low IL = -5mA VOH Output Swing High IL = 5mA ISC Short Circuit Current Short to GND -4.92 4.85 4.92 V ±120 mA Power Supply Performance PSRR Power Supply Rejection Ratio VS is moved from ±2.25V to ±7.75V IS Supply Current (Per Buffer) No Load 60 80 500 dB 750 µA Dynamic Performance SR Slew Rate  -4.0V ≤ VOUT ≤ 4.0V, 20% to 80% tS Settling to +0.1% VO=2V Step 500 ns BW -3dB Bandwidth RL = 10kΩ, CL = 10pF 12 MHz CS Channel Separation f = 5MHz 75 dB 1. Measured over the operating temperature range 2. Slew rate is measured on rising and falling edges 2 7 10 V/µs Electrical Characteristics VS+ = +5V, VS- = 0V, RL = 10kΩ and CL = 10pF to 2.5V, TA = 25°C unless otherwise specified. Parameter Description Condition Min Typ Max 10 Unit Input Characteristics VOS Input Offset Voltage VCM = 2.5V 2 TCVOS Average Offset Voltage Drift  5 VCM = 2.5V IB Input Bias Current RIN Input Impedance CIN Input Capacitance AV Voltage Gain 2 50 1 0.995 nA GΩ 1.35 0.5 ≤ VOUT ≤ 4.5V mV µV/°C pF 1.005 V/V 150 mV Output Characteristics VOL Output Swing Low IL = -5mA VOH Output Swing High IL = 5mA ISC Short Circuit Current Short to GND 80 4.85 4.92 V ±120 mA Power Supply Performance PSRR Power Supply Rejection Ratio VS is moved from 4.5V to 15.5V IS Supply Current (Per Buffer) No Load 60 80 500 dB 750 µA Dynamic Performance SR Slew Rate  1V ≤ VOUT ≤4V, 20% to 80% tS Settling to +0.1% VO = 2V Step 500 ns BW -3dB Bandwidth RL = 10 kΩ, CL = 10pF 12 MHz CS Channel Separation f = 5MHz 75 dB 1. Measured over the operating temperature range 2. Slew rate is measured on rising and falling edges 3 7 10 V/µs EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Electrical Characteristics VS+ = +15V, VS- = 0V, RL = 10kΩ and CL = 10pF to 7.5V, TA = 25°C unless otherwise specified. Parameter Description Condition Min Typ Max 14 Unit Input Characteristics VOS Input Offset Voltage VCM = 7.5V 2 TCVOS Average Offset Voltage Drift  5 VCM = 7.5V IB Input Bias Current RIN Input Impedance CIN Input Capacitance AV Voltage Gain 2 50 1 0.995 nA GΩ 1.35 0.5 ≤ VOUT ≤ 14.5V mV µV/°C pF 1.005 V/V 150 mV Output Characteristics VOL Output Swing Low IL = -5mA VOH Output Swing High IL = 5mA ISC Short Circuit Current Short to GND 80 14.85 14.92 V ±120 mA Power Supply Performance PSRR Power Supply Rejection Ratio VS is moved from 4.5V to 15.5V IS Supply Current (Per Buffer) No Load 60 80 500 dB 750 µA Dynamic Performance SR Slew Rate  1V ≤ VOUT ≤14V, 20% to 80% tS Settling to +0.1% VO = 2V Step 500 ns BW -3dB Bandwidth RL = 10 kΩ, CL = 10pF 12 MHz CS Channel Separation f = 5MHz 75 dB 1. Measured over the operating temperature range 2. Slew rate is measured on rising and falling edges 4 7 10 V/µs Typical Performance Curves Input Offset Voltage Distribution Input Offset Voltage Drift 35 2000 VS=±5V TA=25°C Typical Production Distribution 1600 VS=±5V TA=25°C 30 Typical Production Distribution Quantity (Buffers) Quantity (Buffers) 25 1200 800 20 15 10 400 5 Input Offset Voltage vs Temperature 19 17 15 13 9 11 7 Input Bias Current vs Temperature 10 4 5 2 VS=±5V Input Bias Current (nA) Input Offset Voltage (mV) 5 1 12 8 10 4 2 0 -2 -4 -6 -8 -10 -12 6 Input Offset Voltage, TCVOS (µ V/°C) Input Offset Voltage (mV) 0 -5 -10 -50 0 50 Temperature (°C) 100 VS=±5V 0 -2 -4 -50 150 0 50 100 150 Temperature (°C) Output Low Voltage vs Temperature Output High Voltage vs Temperature -4.91 4.97 -4.92 VS=±5V IOUT=5mA 4.96 Output Low Voltage (V) Output High Voltage (V) 3 0 0 4.95 4.94 VS=±5V IOUT=-5mA -4.93 -4.94 -4.95 -4.96 4.93 -50 0 50 100 -4.97 -50 150 Temperature (°C) 5 0 50 Temperature (°C) 100 150 EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Dual 12MHz Rail-to-Rail Input-Output Buffer Typical Performance Curves Slew Rate vs Temperature Voltage Gain vs Temperature 1.001 13 12.5 VS=±5V VS=±5V Slew Rate (V/µ S) Voltage Gain (V/V) 1.0005 1.0000 12 11.5 11 0.9995 10.5 0.999 -50 0 50 100 10 -50 150 0 50 Temperature (°C) Supply Current per Channel vs Temperature Supply Current per Channel vs Supply Voltage 650 VS=±5V 550 Supply Current (µ A) Supply Current (mA) 150 100 Temperature (°C) 0.55 0.5 0.45 TA=25°C 450 350 0.4 -50 0 50 100 250 150 5 0 Temperature (°C) 20 15 20 0 Magnitude (Normalized) (dB) 10kΩ -5 10 Supply Voltage (V) Frequency Response for Various CL Frequency Response for Various RL 5 Magnitude (Normalized) (dB) EL5221C EL5221C 1kΩ 560Ω CL=10pF VS=±5V 150Ω -10 10 RL=10kΩ VS=±5V 12pF 0 50pF -10 100pF -20 1000pF -15 100k 1M 10M -30 100k 100M Frequency (Hz) 1M 10M Frequency (Hz) 6 100M Typical Performance Curves Output Impedance vs Frequency Maximum Output Swing vs Frequency 200 12 Output Impedance (Ω) Maximum Output Swing (VP-P) VS=±5V TA=25°C 160 120 80 40 10 8 VS=±5V TA=25°C RL=10kΩ CL=12pF Distortion <1% 6 4 2 0 10k 100k 1M 0 10k 10M 100k Frequency (Hz) PSRR vs Frequency 80 Input Voltage Noise Spectral Density vs Frequency PSRRVoltage Noise (nV√Hz) PSRR (dB) 10M 600 PSRR+ 60 40 VS=±5V TA=25°C 20 0 100 1k 10k 100k Frequency (Hz) 1M 100 10 1 100 10M Total Harmonic Distortion + Noise vs Frequency 1k 10k 1M 100k Frequency (Hz) 10M 100M Channel Separation vs Frequency Response 0.010 -60 Dual measured Channel A to B Quad measured Channel A to D or B to C Other combinations yield improved rejection. 0.009 0.008 -80 0.007 X-Talk (dB) THD+ N (%) 1M Frequency (Hz) 0.006 0.005 VS=±5V RL=10kΩ VIN=1VRMS 0.004 0.003 -100 VS=±5V RL=10kΩ VIN=220mVRMS -120 0.002 0.001 1k 10k Frequency (Hz) -140 1k 100k 10k 100k Frequency (Hz) 7 1M 6M EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Dual 12MHz Rail-to-Rail Input-Output Buffer Typical Performance Curves Small-Signal Overshoot vs Load Capacitance Settling Time vs Step Size 100 5 3 2 Step Size (V) 60 VS=±5V RL=10kΩ CL=12pF TA=25°C 4 VS=±5V RL=10kΩ VIN=±50mV TA=25°C 80 Overshoot (%) EL5221C EL5221C 40 0.1% 1 0 -1 -2 20 0.1% -3 -4 0 -5 10 100 1000 0 200 Load Capacitance (pF) Large Signal Transient Response 1V 400 Settling Time (nS) 600 Small Signal Transient Response 50mV 1µ S VS=±5V TA=25°C RL=10kΩ CL=12pF 8 200ns VS=±5V TA=25°C RL=10kΩ CL=12pF 800 Pin Descriptions SOT23-6 MSOP-8 Pin Name 1 3 VINA Function Equivalent Circuit Buffer A Input VS+ VSCircuit 1 2 4 VS - Negative Supply Voltage 3 5 VINB Buffer B Input 4 7 VOUTB (Reference Circuit 1) Buffer B Output VS+ VSGND Circuit 2 5 8 VS + 6 1 VOUTA Positive Supply Voltage Buffer A Output (Reference Circuit 2) 9 EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Dual 12MHz Rail-to-Rail Input-Output Buffer Applications Information Product Description Short Circuit Current Limit The EL5221C unity gain buffer is fabricated using a high voltage CMOS process. It exhibits rail-to-rail input and output capability and has low power consumption (500µA per buffer). These features make the EL5221C ideal for a wide range of general-purpose applications. When driving a load of 10kΩ and 12pF, the EL5221C has a -3dB bandwidth of 12MHz and exhibits 10V/µS slew rate. The EL5221C 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. Operating Voltage, Input, and Output Output Phase Reversal The EL5221C is 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 EL5221C specifications are stable over both the full supply range and operating temperatures of -40°C to +85°C. Parameter variations with operating voltage and/or temperature are shown in the typical performance curves. The EL5221C is immune to phase reversal as long as the input voltage is limited from VS- -0.5V to VS+ +0.5V. Figure 2 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. The output swings of the EL5221C 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 1 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. 5V 1V 10µ S VS=±2.5V TA=25°C VIN=6VP-P 10µ S 5V Input 1V VS=±5V TA=25°C VIN=10VP-P Figure 2. Operation with Beyond-the-Rails Input Output EL5221C EL5221C Power Dissipation With the high-output drive capability of the EL5221C 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 application to Figure 1. Operation with Rail-to-Rail Input and Output 10 determine if load conditions need to be modified for the buffer to remain in the safe operating area. the device’s power derating curves. To ensure proper operation, it is important to observe the recommended derating curves shown in Figure 3 and Figure 4. The maximum power dissipation allowed in a package is determined according to: Package Mounted on a JEDEC JESD51-7 High Effective Thermal Conductivity Test Board T JM AX – T A MA X P D MAX = -------------------------------------------Θ JA 1 870mW MAX TJ=125°C 0.8 Power Dissipation (W) where: TJMAX = Maximum Junction Temperature TAMAX= Maximum Ambient Temperature ΘJA = Thermal Resistance of the Package MS OP -8 0.6 435mW 0.4 SO T23 -6 2 30° C/W 0.2 PDMAX = Maximum Power Dissipation in the Package 11 5° C/ W 0 0 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: 25 50 75 85 100 Ambient Temperature (°C) 125 150 Figure 3. Package Power Dissipation vs Ambient Temperature P D MAX = Σi [ V S × I SMA X + ( V S + – V OU T i ) × I L OA D i ] when sourcing, and Package Mounted on a JEDEC JESD51-3 Low Effective Thermal Conductivity Test Board 0.6 P D MA X = Σi [ V S × I SM AX + ( V OU T i – V S - ) × I L OA D i ] Power Dissipation (W) when sinking. where: i = 1 to 2 for Dual Buffer VS = Total Supply Voltage MAX TJ=125°C 486mW 0.5 391mW 0.4 MS OP -8 2 SO T2 3-6 25 6° C 0.3 0.2 06 °C /W /W 0.1 ISMAX = Maximum Supply Current Per Channel 0 VOUTi = Maximum Output Voltage of the Application 0 25 50 75 85 100 125 150 Ambient Temperature (°C) ILOADi = Load Current Figure 4. Package Power Dissipation vs Ambient Temperature If we set the two PDMAX equations equal to each other, we can solve for RLOADi to avoid device overheat. Figure 3 and Figure 4 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 Unused Buffers It is recommended that any unused buffer have the input tied to the ground plane. 11 EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer Driving Capacitive Loads Power Supply Bypassing and Printed Circuit Board Layout The EL5221C 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 The EL5221C can provide gain at high frequency. 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+ to pin to VS- pin. A 4.7µF tantalum capacitor should then be connected in parallel, placed in the region of the buffer. 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. 12 EL5221C EL5221C Dual 12MHz Rail-to-Rail Input-Output Buffer General Disclaimer Specifications contained in this data sheet are in effect as of the publication date shown. Elantec, Inc. reserves the right to make changes in the circuitry or specifications contained herein at any time without notice. Elantec, Inc. assumes no responsibility for the use of any circuits described herein and makes no representations that they are free from patent infringement. November 7, 2000 WARNING - Life Support Policy Elantec, Inc. products are not authorized for and should not be used within Life Support Systems without the specific written consent of Elantec, Inc. Life Support systems are equipment intended to support or sustain life and whose failure to perform when properly used in accordance with instructions provided can be reasonably expected to result in significant personal injury or death. Users contemplating application of Elantec, Inc. Products in Life Support Systems are requested to contact Elantec, Inc. factory headquarters to establish suitable terms & conditions for these applications. Elantec, Inc.’s warranty is limited to replacement of defective components and does not cover injury to persons or property or other consequential damages. Elantec Semiconductor, Inc. 675 Trade Zone Blvd. Milpitas, CA 95035 Telephone: (408) 945-1323 (888) ELANTEC Fax: (408) 945-9305 European Office: +44-118-977-6080 Japan Technical Center: +81-45-682-5820 13 Printed in U.S.A.