AD8552M/TR

AD8551/52 1.5MHZ Zero-Drift CMOS Rail-to-Rail IO Opamp with RF Filter Features o • Single-Supply Operation from +2.1V ~ +5.5V • Zero Drift: 0.05µV/ C (Max.) • Rail-to-Rail Input / Output • Embedded RF Anti-EMI Filter • Gain-Bandwidth Product: 1.5MHz (Typ. @25°C) • Small Package: • Low Input Bias Current: 20pA (Typ. @25°C) AD8551 Available in SOT23-5 and SOP-8 Packages • Low Offset Voltage: 5uV (Max. @25°C) AD8552 Available in MSOP-8 and SOP-8 Packages • Quiescent Current: 320µA per Amplifier (Typ.) • Operating Temperature: -40°C ~ +125°C General Description The AD855X amplifier is single/dual supply, micro-p ower, zero-drift CMOS operational amplifiers, the amplifiers offer bandwidth of 1.5MHz, rail-to-rail inputs and outputs, and single-supply operation from 2.1V to 5.5V. AD855X uses chopper stabilized technique to provide very low offset voltage (less than 5µV maximum) and near zero drift over temperature. Low quiescent supply current of 320µA per amplifier and very low input bias current of 20pA make the devices an ideal choice for low offset, low power consumption and high impedance applications. The AD855X offers excellent CMRR without the crossover associated with traditional complementary input stages. This design results in superior performance for driving analog-to-digital converters (ADCs) without degradation of differential linearity. The AD8551 is available in SOT23-5 and SOP8 packages. And the AD8552 is available in MSOP8 and SOP8 packages. The o o extended temperature range of -40 C to +125 C over all supply voltages offers additional design flexibility. Applications • Transducer Application • Handheld Test Equipment • Temperature Measurements • Battery-Powered Instrumentation • Electronics Scales Pin Configuration AD8551Y AD8552 AD8551 Figure 1. Pin Assignment Diagram http://www.hgsemi.com.cn 1 2018 AUG AD8551/52 Absolute Maximum Ratings Condition Min Max -0.5V +7.5V Analog Input Voltage (IN+ or IN-) Vss-0.5V VDD+0.5V PDB Input Voltage Vss-0.5V +7V -40°C +125°C Power Supply Voltage (VDD to Vss) Operating Temperature Range Junction Temperature +160°C Storage Temperature Range Lead Temperature (soldering, 10sec) Package Thermal Resistance (TA=+25 -55°C +150°C +260°C ℃) SOP-8, θJA 125°C/W MSOP-8, θJA 216°C/W SOT23-5, θJA 190°C/W ESD Susceptibility HBM 6KV MM 400V Note: Stress greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions outside those indicated in the operational sections of this specification are not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability. http://www.hgsemi.com.cn 2 2018 AUG AD8551/52 Electrical Characteristics ℃, unless otherwise noted.) (VS = +5V, VCM = +2.5V, VO = +2.5V, TA = +25 PARAMETER CONDITIONS MIN TYP MAX UNITS Input Offset Voltage (VOS) 1 5 µV Input Bias Current (IB) 20 pA Input Offset Current (IOS) 10 pA VCM = 0V to 5V 110 dB RL = 10kΩ, VO = 0.3V to 4.7V 145 dB INPUT CHARACTERISTICS Common-Mode Rejection Ratio (CMRR) Large Signal Voltage Gain ( AVO) Input Offset Voltage Drift (∆VOS/∆T) 50 nV/ ℃ OUTPUT CHARACTERISTICS Output Voltage High (VOH) Output Voltage Low (VOL) Short Circuit Limit (ISC) RL = 100kΩ to - VS 4.998 V RL = 10kΩ to - VS 4.994 V RL = 100kΩ to + VS 2 mV RL = 10kΩ to + VS 5 mV RL =10Ω to - VS 43 mA 30 mA Output Current (IO) POWER SUPPLY Power Supply Rejection Ratio (PSRR) VS = 2.5V to 5.5V 115 dB Quiescent Current (IQ) VO = 0V, RL = 0Ω 320 µA Gain-Bandwidth Product (GBP) G = +100 1.5 MHz Slew Rate (SR) RL = 10kΩ 0.84 V/µs 0.10 ms 0.81 µVP-P 49 nV / Hz DYNAMIC PERFORMANCE Overload Recovery Time NOISE PERFORMANCE Voltage Noise (en p-p) 0Hz to 10Hz Voltage Noise Density (en) f = 1kHz http://www.hgsemi.com.cn 3 2018 AUG AD8551/52 Typical Performance characteristics Output Voltage (500mV/div) CL=300pF RL=2kΩ AV=+1 Large Signal Transient Response at +2.5V CL=300pF RL=2kΩ AV=+1 Time(4µs/div) Time(2µs/div) Small Signal Transient Response at +5V Small Signal Transient Response at +2.5V CL=50pF RL=∞ AV=+1 Output Voltage (50mV/div) Output Voltage (50mV/div) Output Voltage (1V/div) Large Signal Transient Response at +5V CL=50pF RL=∞ AV=+1 Time(4µs/div) Time(4µs/div) Closed Loop Gain vs. Frequency at +5V Closed Loop Gain vs. Frequency at +2.5V G=-100 Closed Loop Gain (dB) Closed Loop Gain (dB) G=-100 G=-10 G=+1 Frequency (kHz) http://www.hgsemi.com.cn G=-10 G=+1 Frequency (kHz) 4 2018 AUG AD8551/52 Typical Performance characteristics Phase Shift(Degrees) Open Loop Gain Open Loop Gain (dB) Phase Shift VL=0pF RL=∞ Open Loop Gain, Phase Shift vs. Frequency at +2.5V Phase Shift(Degrees) Open Loop Gain (dB) Open Loop Gain, Phase Shift vs. Frequency at +5V Phase Shift VL=0pF RL=∞ Open Loop Gain Frequency (Hz) Frequency (Hz) Positive Overvoltage Recovery Negative Overvoltage Recovery ± Open Loop Gain (dB) VSY= 2.5V VIN=-200mVp-p (RET to GND) CL=0pF RL=10kΩ AV=-100 ± VSY= 2.5V VIN=-200mVp-p (RET to GND) CL=0pF RL=10kΩ AV=-100 Time (4µs/div) Time (40µs/div) 0.1Hz to 10Hz Noise at +5V 0.1Hz to 10Hz Noise at +2.5V G=10000 Noise (2mv/div) Noise (2mv/div) G=10000 Time (10s/div) http://www.hgsemi.com.cn Time (10s/div) 5 2018 AUG AD8551/52 Application Note Size AD855X series op amps are unity-gain stable and suitable for a wide range of general-purpose applications. The small footprints of the AD855X series packages save space on printed circuit boards and enable the design of smaller electronic products. Power Supply Bypassing and Board Layout AD855X series operates from a single 2.1V to 5.5V supply or dual ±1.05V to ±2.75V supplies. For best performance, a 0.1µF ceramic capacitor should be placed close to the VDD pin in single supply operation. For dual supply operation, both VDD and VSS supplies should be bypassed to ground with separate 0.1µF ceramic capacitors. Low Supply Current The low supply current (typical 320uA per channel) of AD855X series will help to maximize battery life . They are ideal for battery powered systems Operating Voltage AD855X series operate under wide input supply voltage (2.1V to 5.5V). In addition, all temperature speci fications apply from o o -40 C to +125 C. Most behavior remains unchanged throughout the full operating voltage range. These guarantees ensure operation throughout the single Li-Ion battery lifetime Rail-to-Rail Input The input common-mode range of AD855X series extends 100mV beyond the supply rails (V SS-0.1V to VDD+0.1V). This is achieved by using complementary input stage. For normal operation, inputs should be limited to this range. Rail-to-Rail Output Rail-to-Rail output swing provides maximum possible dynamic range at the output. This is particularly important when operating in low supply voltages. The output voltage of AD855X series can typically swing to less than 5mV from supply rail in light resistive loads (>100kΩ), and 60mV of supply rail in moderate resistive loads (10kΩ). Capacitive Load Tolerance The AD855x family is optimized for bandwidth and speed, not for driving capacitive loads. Output capacitance will create a pole in the amplifier’s feedback path, leading to excessive peaking and potential oscillation. If dealing with load capacitance is a requirement of the application, the two strategies to consider are (1) using a small resistor in series with the amplifier’s output and the load capacitance and (2) reducing the bandwidth of the amplifier’s feedback loop by increasing the overall noise gain. Figure 2. shows a unity gain follower using the series resistor strategy. The resistor isolates the output from the capacitance and, more importantly, creates a zero in the feedback path that compensates for the pole created by the output capacitance. Figure 2. Indirectly Driving a Capacitive Load Using Isolation Resistor The bigger the RISO resistor value, the more stable VOUT will be. However, if there is a resistive load RL in parallel with the capacitive load, a voltage divider (proportional to RISO/RL) is formed, this will result in a gain error. The circuit in Figure 3 is an improvement to the one in Figure 2. RF provides the DC accuracy by feed-forward the VIN to RL. CF http://www.hgsemi.com.cn 6 2018 AUG AD8551/52 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 the phase margin in the overall feedback loop. Capacitive drive can be increased by increasing the value of CF. This in turn will slow down the pulse response. Figure 3. Indirectly Driving a Capacitive Load with DC Accuracy http://www.hgsemi.com.cn 7 2018 AUG AD8551/52 Typical Application Circuits Differential amplifier The differential amplifier allows the subtraction of two input voltages or cancellation of a signal common the two inputs. It is useful as a computational amplifier in making a differential to single-end conversion or in rejecting a common mode signal. Figure 4. shown the differential amplifier using AD855X. Figure 4. Differential Amplifier VOUT= ( RR13++RR24 ) RR14 VIN − RR12 VIP +( RR13++RR24 ) RR13 VREF If the resistor ratios are equal (i.e. R1=R3 and R2=R4), then VOUT = R2 R1 (VIP − VIN ) + VREF Low Pass Active Filter The low pass active filter is shown in Figure 5. The DC gain is defined by –R2/R1. The filter has a -20dB/decade roll-off after its corner frequency ƒC=1/(2πR3C1). Figure 5. Low Pass Active Filter http://www.hgsemi.com.cn 8 2018 AUG AD8551/52 Instrumentation Amplifier The triple AD855X can be used to build a three-op-amp instrumentation amplifier as shown in Figure 6. The amplifier in Figure 6 is a high input impedance differential amplifier with gain of R2/R1. The two differential voltage followers assure the high input impedance of the amplifier. Figure 6. Instrument Amplifier . http://www.hgsemi.com.cn 9 2018 AUG