ZL40121 Low Power, Current Feedback Dual Operational Amplifier Data Sheet Features • • • • • April 2003 280MHz small signal bandwidth 1100V/µs slew rate 3.3mA/channel static supply current 60Mhz gain flatness to +/- 0.1dB 8 pin SOIC Ordering Information ZL40121/DCA ZL40121/DCB -40°C to +85°C Applications • • • • • (tubes) 8 lead SOIC (tape and reel) 8 lead SOIC The 280MHz Av=+1V/V small signal bandwidth and 1100V/µs slew rate make the device an excellent solution for component video applications such as driving RGB signals down significant cable lengths. Video switchers/routers Video line drivers Twisted pair driver/receiver Active filters Cable drivers Other applications which may take advantage of the ZL40121 dynamic performance features and matched amplifiers include low cost high order active filters and twisted pair driver/receivers. Description The ZL40121 is a low power, dual, current feedback operational amplifier offering high performance at a low cost. The device provides a very high output current drive capability of 65mA while requiring only 3.3mA of static supply current per channel. This feature makes the ZL40121 the ideal choice where a high density of high speed devices is required. Out_1 8 V+ 1 In_n_1 2 7 Out_2 1 In_p_1 3 6 In_n_2 2 V- 4 ZL40121 5 In_p_2 Figure 1 - Functional Block Diagram and Pin Connection 1 ZL40121 Data Sheet Application Notes Current Feedback Op Amps Current feedback op amps offer several advantages over voltage feedback amplifiers: • • • AC bandwidth not dependent on closed loop gain High Slew Rate Fast settling time The architecture of the current feedback opamp consists of a high impedance non-inverting input and a low impedance inverting input which is always feedback connected. The error current is amplified by a transimpedance amplifier which can be considered to have gain Z( f ) = Zo f 1 + j fo where Zo is the DC gain. It can be shown that the closed loop non-inverting gain is given by Vout = Vin Av fR f 1 + j fo Zo where Av is the DC closed loop gain, Rf is the feedback resistor. The closed loop bandwidth is therefore given by BWCL = f o Z o GBOL = Rf Rf and for low values of closed loop gain Av depends only on the feedback resistor Rf and not the closed loop gain. This can readily be seen from the performance characteristic frequency response graph with varying Rf It can be shown that increasing the value of Rf • • • • • Increases closed loop stability Decreases loop gain Decreases bandwidth Reduces gain peaking Reduces overshoot Using a resistor value of Rf=510Ω for Av=+2 V/V gives good stability and bandwidth. However since requirements for stability and bandwidth vary it may be worth some experimentation to find the optimal Rf for a given application. Layout Considerations Correct high frequency operation requires a considered PCB layout as stray capacitances have a strong influence over high frequency operation for this device. This is particularly important for high performance current feedback opamps. The Zarlink evaluation board serves as a good example layout that should be copied. The following guidelines should be followed: • • • Include 6.8uF tantalum and 0.1uF ceramic capacitors on both positive and negative supplies Remove the ground plane under and around the part, especially near the input and output pins to reduce parasitic capacitances Minimize all trace lengths to reduce series inductance 2 Zarlink Semiconductor Inc. ZL40121 Data Sheet Application Diagrams Vcc 6.8uF • • • 0.1uF Vin • Vout • ½ ZL40121 Rf Rin • Ra • 0.1uF • • Vout Rf = Av = 1 + Vin Ra 6.8uF Vee Figure 2 - Non-inverting Gain • Vcc 6.8uF • • • Rb 0.1uF Vout ½ ZL40121 Vin Rf • • Ra Rin • 0.1uF • • Vout Rf = Av = − Vin Ra 6.8uF Vee Figure 3 - Inverting Gain Zarlink Semiconductor Inc. 3 ZL40121 Data Sheet Absolute Maximum Ratings Parameter Symbol Min Max Units VIN ±1.2 V 1 Vin Differential 2 Output Short Circuit Protection VOS/C See Apps Note in this data sheet 3 Supply voltage V+, V- ±6.5 V 4 Voltage at Input Pins 5 Voltage at Output Pins 6 EDS Protection (HBM Human Body Model) (see Note 2) 7 Storage Temperature 8 9 Note 1: V(+IN), V(-IN) V- V+ V VO V- V+ V 2 (see Note 3) kV -55 +150 °C Latch-up test ±100mA for 100ms (see Note 4) Supply transient test 20% pulse for 100ms (see Note 5) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics. Note 2: Human body model, 1.5kΩ in series with 100pF. Machine model, 20Ωin series with 100pF. Note 3: 0.8kV between the pairs of +INA, -INA and +INB pins only. 2kV between supply pins, OUTA or OUTB pins and any input pin. Note 4: ±100mA applied to input and output pins to force the device to go into "latch-up". The device passes this test to JEDEC spec 17. Note 5: Positive and Negative supply transient testing increases the supplies by 20% for 100ms. Operating Range Characteristic 4 Min Typ Max Units Supply Voltage (Vcc) ±4.0 ±6.0 V Operating Temperature (Ambient) -40 +85 °C Junction to Ambient resistance Rth(j-a) 150 °C 4 layer FR4 board Junction to Case resistance Rth(j-c) 60 °C 4 layer FR4 board Zarlink Semiconductor Inc. Comments ZL40121 Data Sheet Electrical Characteristics - Vcc=±5V, Tamb=25C(typ.),Tamb=-40C to +85C(min-max), Av=+2V/V, Rf=510Ω, Rload=100Ω unless specified Typ 25C Min/ Max 25C Min /Max –40 to +85C Av=+1; Vo < 0.5Vp-p; Rf=1.5kΩ 280 - - MHz C Av=+2; Vo < 0.5Vp-p; Rf=510Ω 230 - - MHz C Av=+2; Vo < 5Vp-p; Rf=510Ω 130 - - MHz C +/- 0.1dB Flatness Av=+2; Vo < 0.5Vp-p; Rf=510Ω 60 - - MHz C Differential Gain (NTSC) Rload=150Ω 0.02 - - % C Differential Phase (NTSC) Rload=150Ω 0.06 - - deg. C Vout=0.5V Step 1.4 - - ns C Vout=5V Step 3.6 - - ns C Settling Time to 0.1% Vout=2V Step 6 - - ns C Overshoot Vout=0.5V Step 6 - - % C Slew Rate Vout=5V Step 1100 - - V/µs C Characteristic Conditions Units Test Type1 Frequency Domain Response -3dB Bandwidth Time Domain Response Rise and Fall Time Noise and Distortion 2nd Harmonic Distortion Vout=2Vp-p, 1MHz -78 - - dBc C 3nd Harmonic Distortion Vout=2Vp-p, 1MHz -88 - - dBc C Voltage >1MHz 6.4 - - nV Hz C Non-Inverting Current >1MHz 1.0 - - pV Hz C Inverting Current >1MHz 9.3 - - pA Hz C Input Offset Voltage 1.4 ± 6.0 ± 7.5 Average Drift - - 15 1.3 ±2.6 - - Equivalent Input Noise Static, DC Performance Input Bias Current – Non-inverting Average Drift Zarlink Semiconductor Inc. mV A uV/deg. C C ±2.8 uA A 2.6 nA/deg. C C 5 ZL40121 Data Sheet Characteristic Conditions Input Bias Current – Inverting Average Drift Typ 25C Min/ Max 25C Min /Max –40 to +85C 4.4 ±14 ±15 uA A - - 16 nA/deg. C C Units Test Type1 Power Supply Rejection Ratio (+ve) DC 65 63 62 dB A Power Supply Rejection Ratio (-ve) DC 62 58 56 dB A Common Mode Rejection Ratio DC 57 54 53 dB A Supply Current (per Channel) Quiescent 3.3 4.5 4.7 mA A Input Resistance (Non-inverting) 19.0 - - MΩ C Input Capacitance (Non-inverting) 1 - - pF C ±2.3 ±2.2 ±1.9 V A ±2.8 ±2.7 ±2.6 V A 65 - - mA C 110 - - mΩ C Miscellaneous Performance Common Mode Input Range Output Voltage Range Rload=100Ω Output Current (max) Output Resistance, Closed Loop DC NOTE 1: Test Types: (A) 100% tested at 25°C. Over temperature limits are set by characterization and simulation. (B) Limits set by characterization or simulation. (C) Typical value only for information. 6 Zarlink Semiconductor Inc. ZL40121 Data Sheet Typical Performance Characteristics - Tamb=25degC, Vsupply=± 5V, Rload=100Ω, Av=+2V/V, Rf=510Ω, unless otherwise specified Non-Inverting Frequency Response 2 200 Av =+2 Rf = 510 Normalised Gain (dB) -2 Av =+1 Rf = 1.1k Av =+8 Rf = 200 -4 150 100 50 Phase -6 0 -8 -50 Av =+4 Rf = 150 -10 -12 -100 -150 Vo = 0.5Vp-p -14 1 Phase (deg.) Gain 0 10 100 -200 1000 Frequency (MHz) Zarlink Semiconductor Inc. 7 ZL40121 Data Sheet Non-Inverting Frequency Response varying Rf 2 Rf=390 0 Normalised Gain (dB) -2 Rf=250 Rf=700 -4 -6 Rf=510 -8 -10 -12 -14 Vo=0.5Vp-p -16 -18 10 100 1000 Frequency (MHz) Frequency Response for Varying Rload 2 0 RL = 1k Gain (dB) -2 RL = 100 -4 RL = 25 -6 Vo = 0.5V p-p -8 -10 10 100 Frequency (MHz) 8 Zarlink Semiconductor Inc. 1000 ZL40121 Data Sheet Large Signal Gain 0 -2 Vo = 2V p-p Vo = 1V p-p Vo = 5V p-p -6 -8 Vo = 4V p-p -10 -12 -14 -16 10 100 1000 Frequency (MHz) Harmonic Distortion vs Frequency -40 Vo = 2V p-p 2nd & 3rd Harmonic Distortion (dBc) Gain (dB) -4 -50 -60 2nd Harmonic -70 -80 -90 3rd Harmonic -100 1 10 100 Frequency (MHz) Zarlink Semiconductor Inc. 9 ZL40121 Data Sheet Open Loop Transimpedance Gain and Phase 120 0 -30 Transimpedance Gain 100 90 -60 Transimpedance Phase -90 80 -120 70 -150 60 -180 50 -210 40 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 1.0E+08 Transimpedance Phase Transimpedance Gain 110 -240 1.0E+09 Frequency (Hz) CMRR 70 T = - 40 degC Rejection Ration (dB) 60 50 T = + 25 degC T = + 85 degC 40 30 20 10 0 1.0E+03 1.0E+04 1.0E+05 1.0E+06 Frequency (Hz) 10 Zarlink Semiconductor Inc. 1.0E+07 1.0E+08 ZL40121 Data Sheet PSRR +ve 80 T = - 40 degC Rejection Ration (dB) 70 60 T = + 25 degC T = + 85 degC 50 40 30 20 10 0 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 1.0E+08 Frequency (Hz) PSRR -ve 70 T = - 40 degC Rejection Ration (dB) 60 50 T = + 25 degC T = + 85 degC 40 30 20 10 0 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 1.0E+08 Frequency (Hz) T Zarlink Semiconductor Inc. 11 ZL40121 Data Sheet Input Voltage and Current Noise Current Noise (pA/SQRT(Hz) Voltage Noise (nV/SQRT(Hz) 100 Inverting Input Current Noise 10 Input Voltage Noise 1 Non-Inverting Input Current 0.1 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05 1.0E+06 1.0E+07 Frequency (Hz) Supply Current vs Temperature 3.55 3.50 Supply Current (mA) 3.45 3.40 3.35 3.30 3.25 3.20 3.15 3.10 3.05 3.00 -40 -20 0 20 40 60 Die Temp (deg. C) 12 Zarlink Semiconductor Inc. 80 100 120 140 ZL40121 Data Sheet DC Drift Over Temperature 5.00 4.00 3.50 Input Bias Inv 3.00 2.50 Input Offset Voltage 2.00 1.50 1.00 Input Bias Non-Inv 0.50 0.00 -40 -20 0 20 40 60 80 100 120 140 Die Temp (deg. C) Large and Small Signal Pulse Response 3 0.6 Vout = 5V Step 0.4 1 0.2 Vout = 0.5V Step 0 0 -1 -0.2 -2 -0.4 -3 Small Signal Vout (V) 2 Large Signal Vout (V) Input Offset Voltage (mV) Input Bias Current (uA) 4.50 -0.6 0 10 20 30 40 50 60 70 80 Time (ns) Zarlink Semiconductor Inc. 13 ZL40121 Data Sheet Closed Loop Output Impedance Closed Loop Output Impedance (Ohms) 10 1 0.1 0.01 0.01 0.1 1 10 100 Frequency (MHz) Differential Gain & Phase ZL40120 / ZL40121 NTSC RL=150? Best fit Gain Best fit Phase 0.07 0.06 0.05 Differential Gain & Phase (?% & ?°) 0.04 0.03 0.02 0.01 0 -0.01 -0.02 -0.03 -0.04 -0.05 -0.06 -0.07 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 bias voltage 14 Zarlink Semiconductor Inc. 0.2 0.3 0.4 0.5 0.6 0.7 For more information about all Zarlink products visit our Web Site at www.zarlink.com Information relating to products and services furnished herein by Zarlink Semiconductor Inc. or its subsidiaries (collectively “Zarlink”) is believed to be reliable. However, Zarlink assumes no liability for errors that may appear in this publication, or for liability otherwise arising from the application or use of any such information, product or service or for any infringement of patents or other intellectual property rights owned by third parties which may result from such application or use. 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