COS1333TR

COS1333, COS2333, COS4333 1.8V, 18µA, RRIO Zero-Drift Operational Amplifiers Features General Description ■ Low offset Voltage: 20µV (Max.) The COS1333 (single), COS2333 (dual) and ■ Zero Drift: 0.05µV/ºC COS4333 (quad) are micro power, zero-drift ■ Low Quiescent Current: 18μA operational amplifiers operated on 1.8 to 5.5 ■ Gain Bandwidth Product: 350kHz supplies. ■ Operates on 1.8V ~ 5.5V Supplies stabilized technique to provide very low offset ■ Slew Rate: 0.2V/µs voltage (less than 30µV maximum) and near ■ Rail-to-Rail Input and Output (RRIO) zero drift over temperature. Low quiescent ■ Unity Gain Stable supply current of 18µA per amplifier and very ■ No Phase Reversal low input bias current make the devices an ■ Extended Temperature Ranges ideal From -40°C to +125°C consumption and high impedance applications. ■ COSx333 choice for family low use offset, chopper low power Small Packaging COS1333 available in SOT23-5/SOP-8 Despite their COS2333 available in SOP-8/MSOP-8 COSx333 family provides excellent overall COS4333 available in SOP14/TSSOP14 performance and versatility. They have both low quiescent current, the rail-to-rail input and output range. The output Applications voltage swing extends to within 5mV of each rail, providing the maximum output dynamic range with excellent overdrive recovery. ■ Sensor Conditioning ■ Temperature Measurements ■ Transducers ■ Test Equipment ■ Medical Instrumentation ■ Battery Powered Instruments ■ A/D converters The information provided here is believed to be accurate and reliable. Cosine Nanoelectronics assumes no reliability for inaccuracies and omissions. Specifications described and contained here are subjected to change without notice on the purpose of improving the design and performance. All of this information described herein should not be implied or granted for any third party. www.cosine-ic.com 1 COSx333 family is unity gain stable and has a gain bandwidth product of 350kHz (typical). Rev 1.7 Copyright@2018 Cosine Nanoelectronics Inc. All rights reserved COS1333, COS2333, COS4333 1. Pin Configuration and Functions COS1333 COS1333 COS2333 COS4333 Pin Functions Name +Vs -Vs -IN +IN OUT NC Description Note A bypass capacitor of 0.1μF as close to the part as possible should be placed between power supply pins or between supply pins and ground. Negative power supply If it is not connected to ground, bypass it with a or ground capacitor of 0.1μF as close to the part as possible. Inverting input of the amplifier. Voltage range of this Negative input pin can go from -Vs -0.3V to +Vs + 0.3V. Non-inverting input of the amplifier. This pin has the Positive input same voltage range as –IN. The output voltage range extends to within millivolts Output of each supply rail. Positive power supply No connection 2. Package and Ordering Information Channel 1 2 Model Order Number COS1333A COS1333TRA COS1333B COS1333TR COS1333C COS1333TRC COS2333A COS2333SRA COS2333B COS2333SRB COS2333C COS2333SRC COS2333A COS2333MRA COS2333B COS2333MRB COS2333C COS2333MRC www.cosine-ic.com Package Package Option Marking Information SOT23-5 Tape and Reel, 3000 COS1333 SOP-8 Tape and Reel, 4000 COS2333SR MSOP-8 Tape and Reel, 3000 COS2333MR 2 COS1333, COS2333, COS4333 4 COS4333A COS4333SRA COS4333B COS4333SRB COS4333C COS4333SRC COS4333A COS4333TRA COS4333B COS4333TRB COS4333C COS4333TRC SOP-14 Tape and Reel, 3000 COS4333SR TSSOP-14 Tape and Reel, 4000 COS4333TR 3. Product Specification 3.1 Absolute Maximum Ratings (1) Parameter Power Supply: +Vs to -Vs Input Voltage Input Current (2) Storage Temperature Range Junction Temperature Operating Temperature Range ESD Susceptibility, HBM Rating Units 6 V -Vs -0.5V to +Vs + 0.5V V 10 mA -65 to 150 °C 150 °C -40 to 125 °C 2000 V (1) Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be operable above the recommended operating conditions and stressing the parts to these levels is not recommended. In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. (2) Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.5V beyond the supply rails should be current-limited to 10mA or less. 3.2 Thermal Data Parameter Rating Unit Package Thermal Resistance 190 (SOT23-5) 206 (MSOP8) 155 (SOP8) 105 (TSSOP14) 82 (SOP14) °C/W Rating Unit 1.8V ~ 5.5V V Input common-mode voltage range -Vs ~ +Vs V Operating ambient temperature -40 to +85 °C 3.3 Recommended Operating Conditions Parameter DC Supply Voltage www.cosine-ic.com 3 COS1333, COS2333, COS4333 3.4 Electrical Characteristics (+VS=+5V, -VS=0, VCM=VS/2, TA=+25°C, RL=10kΩ to VS/2, unless otherwise noted) Parameter Symbol Conditions Min Typ Max 2 20 Unit Input Characteristics COS1333A Input Offset Voltage VOS Input Offset Voltage Drift ΔVOS/ΔT Input Bias Current COS1333B 50 COS1333C 100 COS2333A/COS4333A 5 50 COS2333B/COS4333B 100 COS2333C/COS4333C 150 -40 to 125°C μV 0.01 0.05 μV/°C IB ±25 ±100 pA Input Offset Current IOS ±10 ±70 pA Common-Mode Voltage Range VCM VS = 5.5V 5.6 V Common-Mode Rejection Ratio CMRR VCM =0.1V to 4.9V 120 dB Open-Loop Voltage Gain AOL VO=0.2V to 4.8V 145 dB RL=100kΩ 5 mV RL=10kΩ 15 mV ISR Sourcing 7 mA ISK Sinking -7 mA -0.1 Output Characteristics Output Voltage Swing from Rail Short-Circuit Current Power Supply Operating Voltage Range 1.8 Power Supply Rejection Ratio PSRR VS = 1.8V to 5.5V Quiescent Current / Amplifier IQ GBWP 80 5.5 V 100 dB VS = 1.8V 18 μA G=+1 350 kHz Dynamic Performance Gain Bandwidth Product www.cosine-ic.com 4 COS1333, COS2333, COS4333 Slew Rate SR G = +1 , 2V Output Step 0.2 V/μs en f=1kHz 70 nV/√Hz Noise Performance Voltage Noise Density 3.5 Typical Performance Characteristics (a) (b) Figure 1. Large Signal Transient Response at (a) +5V, (b) +2.5V (a) (b) Figure 2. Small Signal Transient Response at (a) +5V, (b) +2.5V www.cosine-ic.com 5 COS1333, COS2333, COS4333 (a) (b) Figure 3. 0.1Hz to 10Hz Noise at (a) +5V, (b) +2.5V (a) (b) Figure 4. Offset Voltage Production Distribution at (a) +5V, (b) +2.5V www.cosine-ic.com 6 COS1333, COS2333, COS4333 4.0 Application Notes Driving Capacitive Loads Driving large capacitive loads can cause stability problems for voltage feedback op amps. As the load capacitance increases, the feedback loop’s phase margin decreases, and the closed loop bandwidth is reduced. This produces gain peaking in the frequency response, with overshoot and ringing in the step response. A unity gain buffer (G = +1) is the most sensitive to capacitive loads, but all gains show the same general behavior. When driving large capacitive loads with these op amps (e.g., > 100 pF when G = +1), a small series resistor at the output (RISO in Figure 1) improves the feedback loop’s phase margin (stability) by making the output load resistive at higher frequencies. It does not, however, improve the bandwidth. To select RISO, check the frequency response peaking (or step response overshoot) on the bench. If the response is reasonable, you do not need RISO. Otherwise, start RISO at 1 kΩ and modify its value until the response is reasonable. Figure 1. Indirectly Driving Heavy Capacitive Load An improvement circuit is shown in Figure 2. It provides DC accuracy as well as AC stability. RF provides the DC accuracy by connecting the inverting signal with the output, CF and RISO serve to counteract the loss of phase margin by feeding the high frequency component of the output signal back to the amplifier’s inverting input, thereby preserving phase margin in the overall feedback loop. Figure 2. Indirectly Driving Heavy Capacitive Load with DC Accuracy www.cosine-ic.com 7 COS1333, COS2333, COS4333 For non-inverting configuration, there are two others ways to increase the phase margin: (a) by increasing the amplifier’s gain or (b) by placing a capacitor in parallel with the feedback resistor to counteract the parasitic capacitance associated with inverting node, as shown in Figure 3. Figure 3. Adding a Feedback Capacitor in the Noninverting Configuration Power-Supply Bypassing and Layout The COSx333 operates from a single +1.8V to +5.5V supply or dual ±0.9V to ±2.75V supplies. For single-supply operation, bypass the power supply +Vs with a 0.1μF ceramic capacitor which should be placed close to the +Vs pin. For dual-supply operation, both the +Vs and the -Vs supplies should be bypassed to ground with separate 0.1μF ceramic capacitors. 2.2μF tantalum capacitor can be added for better performance. The length of the current path is directly proportional to the magnitude of parasitic inductances and thus the high frequency impedance of the path. High speed currents in an inductive ground return create an unwanted voltage noise. Broad ground plane areas will reduce the parasitic inductance. Thus a ground plane layer is important for high speed circuit design. Typical Application Circuits Differential Amplifier The circuit shown in Figure 4 performs the differential function. If the resistors ratios are equal (R4 / R3 = R2 / R1), then VOUT = (VIP – VIN) × R2 / R1 + VREF. www.cosine-ic.com 8 COS1333, COS2333, COS4333 Figure 4. Differential Amplifier Low Pass Active Filter When receiving low-level signals, limiting the bandwidth of the incoming signals into the system is often required. The simplest way to establish this limited bandwidth is to place an RC filter at the noninverting terminal of the amplifier. If even more attenuation is needed, a multiple pole filter is required. The Sallen-Key filter can be used for this task, as Figure 5. For best results, the amplifier should have a bandwidth that is 8 to 10 times the filter frequency bandwidth. Failure to follow this guideline can result in reduction of phase margin. The large values of feedback resistors can couple with parasitic capacitance and cause undesired effects such as ringing or oscillation in high-speed amplifiers. Keep resistors value as low as possible and consistent with output loading consideration. Figure 5. Two-Pole Low-Pass Sallen-Key Active Filter www.cosine-ic.com 9 COS1333, COS2333, COS4333 5. Package Information 5.1 SOT23-5 (Package Outline Dimensions) 5.2 SOP8 (Package Outline Dimensions) www.cosine-ic.com 10 COS1333, COS2333, COS4333 5.3 MSOP8 (Package Outline Dimensions) 5.4 SOP14 (Package Outline Dimensions) www.cosine-ic.com 11 COS1333, COS2333, COS4333 5.5 TSSOP14 (Package Outline Dimensions) 6. Related Parts Part Number Description COS6042 24kHz, 0.5μA, Nano-Power Op Amps, 1.4V to 5.5V Supply COS8042 160MHz, 5.5mA, High Speed Op Amps, 3V to 12V Supply COS2172 10MHz, 1.2mA, RRIO Op Amps, 4.5 to 40V Supply COS2333 350kHz, 18μA, Precision Op Amps, 1.8 to 5.5V Supply, Zero Drift, Vos