GS321A-CR

GS321A/358A 1MHZ CMOS Rail-to-Rail IO Opamp with RF Filter Features • Single-Supply Operation from +2.1V ~ +5.5V • Embedded RF Anti-EMI Filter • Rail-to-Rail Input / Output • Small Package: • Gain-Bandwidth Product: 1MHz (Typ.) GS321A Available in SOT23-5 and SC70-5 Packages • Low Input Bias Current: 1pA (Typ.) GS358A Available in SOP-8, MSOP-8 and DFN-8 • Low Offset Voltage: 0.5mV (Max.) Packages • Quiescent Current: 40µA per Amplifier (Typ.) • Operating Temperature: -40°C ~ +125°C General Description μ The GS321A family have a high gain-bandwidth product of 1MHz, a slew rate of 0.6V/ s, and a quiescent current of 40 μ A/amplifier at 5V. The GS321A family is designed to provide optimal performance in low voltage and low noise systems. They provide rail-to-rail output swing into heavy loads. The input common mode voltage range includes ground, and the maximum ℃ to input offset voltage is 0.5mV for GS321A family. They are specified over the extended industrial temperature range (-40 +125 ℃). The operating range is from 2.1V to 5.5V. The GS321A single is available in Green SC70-5 and SOT23-5 packages. The GS358A Dual is available in Green SOP-8, MSOP-8 and DFN-8 packages. Applications • ASIC Input or Output Amplifier • Audio Output • Sensor Interface • Piezoelectric Transducer Amplifier • Medical Communication • Medical Instrumentation • Smoke Detectors • Portable Systems Pin Configuration Figure 1. Pin Assignment Diagram V1 1/14 GS321A/358A 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 -55°C Lead Temperature (soldering, 10sec) Package Thermal Resistance (TA=+25 +150°C +260°C ℃) SOP-8, θJA 125°C/W MSOP-8, θJA 216°C/W SOT23-5, θJA 190°C/W SC70-5, θJA 333°C/W ESD Susceptibility HBM 6KV MM 300V 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. Package/Ordering Information MODEL GS321A GS358A V1 CHANNEL Single Dual PACKAGE PACKAGE MARKING DESCRIPTION OPTION INFORMATION GS321A-CR SC70-5 Tape and Reel,3000 321A GS321A-TR SOT23-5 Tape and Reel,3000 321A GS321YA-CR SC70-5 Tape and Reel,3000 321YA GS321YA-TR SOT23-5 Tape and Reel,3000 321YA GS358A-SR SOP-8 Tape and Reel,4000 GS358 GS358A-MR MSOP-8 Tape and Reel,3000 GS358 GS358A-FR DFN-8 Tape and Reel,3000 GS358 ORDER NUMBER 2/14 GS321A/358A Electrical Characteristics (At VS = +5V, RL = 100kΩ connected to VS/2, and VOUT = VS/2, unless otherwise noted.) GS321A/358A PARAMETER SYMBOL CONDITIONS TYP +25 ℃ MIN/MAX OVER TEMPERATURE +25 ℃ -40 ℃ to +85℃ UNITS MIN/MAX mV MAX INPUT CHARACTERISTICS Input Offset Voltage VOS VCM = VS/2 0.1 0.4 0.8 Input Bias Current IB 1 pA TYP Input Offset Current IOS 1 pA TYP Common-Mode Voltage Range VCM -0.1 to +5.6 V TYP Common-Mode Rejection Ratio CMRR Open-Loop Voltage Gain Input Offset Voltage Drift VS = 5.5V VS = 5.5V, VCM = -0.1V to 4V 70 62 62 VS = 5.5V, VCM = -0.1V to 5.6V 68 56 55 RL = 5kΩ, VO = +0.1V to +4.9V 80 70 70 RL = 10kΩ, VO = +0.1V to +4.9V 100 90 85 dB MIN dB MIN AOL ∆VOS/∆T 2.7 µV/ ℃ TYP OUTPUT CHARACTERISTICS VOH RL = 100kΩ 4.997 4.990 4.980 V MIN VOL RL = 100kΩ 3 10 20 mV MAX VOH RL = 10kΩ 4.992 4.970 4.960 V MIN VOL RL = 10kΩ 8 30 40 mV MAX 84 60 45 mA MIN 75 60 45 2.1 2.5 V MIN 5.5 5.5 V MAX 82 60 58 dB MIN 40 60 80 µA MAX 1 MHz TYP Output Voltage Swing from Rail ISOURCE Output Current RL = 10Ω to VS/2 ISINK POWER SUPPLY Operating Voltage Range Power Supply Rejection Ratio PSRR Quiescent Current / Amplifier IQ VS = +2.5V to +5.5V, VCM = +0.5V DYNAMIC PERFORMANCE (CL = 100pF) Gain-Bandwidth Product Slew Rate Settling Time to 0.1% GBP SR G = +1, 2V Output Step 0.6 V/µs TYP tS G = +1, 2V Output Step 5 µs TYP VIN ·Gain = VS 2.6 µs TYP f = 1kHz 27 nV / Hz TYP f = 10kHz 20 nV / Hz TYP Overload Recovery Time NOISE PERFORMANCE Voltage Noise Density V1 en 3/14 GS321A/358A Typical Performance characteristics o At TA=+25 C, VS=+5V, and RL=100KΩ connected to VS/2, unless otherwise noted. Large-Signal Step Response Small-Signal Step Response G=+1 CL=100pF RL=100KΩ Output Voltage (20mV/div) Output Voltage (500mV/div) G=+1 CL=100pF RL=100KΩ Time (2µs/div) Supply Current vs. Supply Voltage Short-Circuit Current vs. Supply Voltage Supply Current (uA) Short-Circuit Current (mA) Time (4µs/div) Supply Voltage (V) Supply Voltage (V) Output Voltage vs. Output Current Output Voltage vs. Output Current Vs=5V Sinking Current Output Current (mA) V1 Output Voltage (V) Output Voltage (V) Sourcing Current Sourcing Current Vs=3V Sinking Current Output Current (mA) 4/14 GS321A/358A Typical Performance characteristics o At TA=+25 C, VS=+5V, and RL=100KΩ connected to VS/2, unless otherwise noted. Supply Current vs. Temperature Vs=5V G=-5 VIN=500mV ℃ Input Voltage Noise Spectral Density vs. Frequency Open Loop Gain, Phase Shift vs. Frequency at +5V Open Loop Gain (dB) Phase Shift (Degrees) Temperature ( ) Voltage Noise (nV/√Hz) Time (2µs/div) Frequency (kHz) CMRR vs. Frequency PSRR vs. Frequency PSRR (dB) CMRR (dB) Frequency (kHz) Frequency (kHz) V1 Supply Current (µA) Overload Recovery Time Frequency (kHz) 5/14 GS321A/358A Application Note Size GS321A family series op amps are unity-gain stable and suitable for a wide range of general-purpose applications. The small footprints of the GS321A family packages save space on printed circuit boards and enable the design of smaller electronic products. Power Supply Bypassing and Board Layout GS321A family 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 40uA per channel) of GS321A family will help to maximize battery life. They are ideal for battery powered systems Operating Voltage GS321A family operates under wide input supply voltage (2.1V to 5.5V). In addition, all temperature specifications 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 GS321A family extends 100mV beyond the supply rails (VSS-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 GS321A family 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 GS321A 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 V1 6/14 GS321A/358A 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 V1 7/14 GS321A/358A 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 GS321A family. Figure 4. Differential Amplifier VOUT= ( RR13++RR24 ) RR14 VIN − RR12 VIP +( RR13++RR24 ) RR31 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 V1 8/14 GS321A/358A Instrumentation Amplifier The triple GS321A family 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 . V1 9/14 GS321A/358A Package Information MSOP-8 V1 10/14 GS321A/358A SOP-8 V1 11/14 GS321A/358A SOT23-5 V1 12/14 GS321A/358A SC70-5 V1 13/14 GS321A/358A DFN-8 V1 14/14