GS8721-CR

GS8721/8722/8724 11MHZ CMOS Rail-to-Rail IO Opamps Features • Single-Supply Operation from +2.1V ~ +5.5V • Quiescent Current: 1.1mA per Amplifier (Typ.) • Rail-to-Rail Input / Output • Operating Temperature: -40°C ~ +125°C • Gain-Bandwidth Product: 11MHz (Typ.) • Small Package: • Low Input Bias Current: 1pA (Typ.) GS8721 Available in SOT23-5, SOP-8 and SC70-5 • Low Offset Voltage: 3.5mV (Max.) Packages • High Slew Rate: 9V/µs GS8722 Available in SOP-8 and MSOP-8 Packages • Settling Time to 0.1% with 2V Step: 0.3µs GS8724 Available in SOP-14 and TSSOP-14 Packages • Low Noise : 8nV/ Hz @10kHz GS8721N Available in SOT23-6 and SC70-6 Packages General Description The GS872X have a high gain-bandwidth product of 11MHz, a slew rate of 9V/ μs, and a quiescent current of 1.1mA per amplifier at 5V. The GS872X are 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 input offset voltage is 3.5mV for GS872X. They are specified over the extended industrial temperature range (-40 ℃ to +125℃). The operating range is from 2.1V to 5.5V. The GS8721 single is available in Green SC70-5, SOT23-5 and SOP-8 packages. The GS8722 dual is available in Green SOP-8 and MSOP-8 packages. The GS8724 Quad is available in Green SOP-14 and TSSOP-14 packages. Applications • Sensors • Audio • Active Filters • Handheld Test Equipment • Cellular and Cordless Phones • Battery-Powered Instrumentation • Laptops and PDAs • A/D Converters Pin Configuration Figure 1. Pin Assignment Diagram V1 1/17 GS8721/8722/8724 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 SOT23-6, θJA 190°C/W SC70-5, θJA 333°C/W ESD Susceptibility HBM 8KV 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. Package/Ordering Information MODEL GS8721 CHANNEL Single GS8722 Dual GS8724 Quad V1 PACKAGE PACKAGE MARKING DESCRIPTION OPTION INFORMATION GS8721-CR SC70-5 Tape and Reel,3000 8721 GS8721-TR SOT23-5 Tape and Reel,3000 8721 GS8721-SR SOP-8 Tape and Reel,4000 GS8721 GS8722-SR SOP-8 Tape and Reel,4000 GS8722 GS8722-MR MSOP-8 Tape and Reel,3000 GS8722 GS8724-TR TSSOP-14 Tape and Reel,3000 GS8724 GS8724-SR SOP-14 Tape and Reel,2500 GS8724 ORDER NUMBER 2/17 GS8721/8722/8724 Electrical Characteristics (At Vs=5V, TA = +25 ℃, V CM = VS/2, RL = 600 Ω, unless otherwise noted.) GS8721/2/4 MIN/MAX OVER TEMPERATURE TYP PARAMETER CONDITIONS +25 ℃ ℃ ℃ to 70℃ 3.5 3.9 +25 0 ℃ to 85℃ ℃ to 125℃ UNITS 4.3 4.6 mV MAX -40 -40 MIN / MAX INPUT CHARACTERISTICS Input Offset Voltage (VOS) 0.8 Input Bias Current (IB) 1 pA TYP Input Offset Current (IOS) 1 pA TYP -0.1 to V TYP Input Common Mode Voltage Range (VCM) VS = 5.5V +5.6 Common Mode Rejection Ratio (CMRR) Open-Loop Voltage Gain (AOL) VS = 5.5V, VCM = -0.1V to 4V 82 VS = 5.5V, VCM = -0.1V to 5.6V 75 RL = 600Ω,VO = 0.15V to 4.85V 90 RL = 10kΩ,VO = 0.05V to 4.95V 108 Input Offset Voltage Drift (∆VOS/∆T) 65 80 64 76 64 75 63 68 dB MIN dB MIN dB MIN dB MIN ℃ 2.4 µV/ TYP RL = 600Ω 0.1 V TYP RL = 10kΩ 0.015 V TYP mA MIN 7.5 Ω TYP Turn-On Time 1.1 µs TYP Turn-Off Time 0.3 µs TYP OUTPUT CHARACTERISTICS Output Voltage Swing from Rail Output Current (IOUT) Closed-Loop Output Impedance 70 f = 100kHz, G = 1 55 45 42 38 POWER-DOWN DISABLE DISABLE Voltage-Off 0.8 V MAX DISABLE Voltage-On 2 V MIN POWER SUPPLY Operating Voltage Range Power Supply Rejection Ratio (PSRR) 2.1 2.1 2.1 2.1 V MIN 5.5 5.5 5.5 5.5 V MAX VS = +2.5V to +5.5V VCM = (-VS) + 0.5V Quiescent Current/Amplifier (IQ) V1 91 74 72 72 68 dB MIN 1.1 1.5 1.65 1.7 1.85 mA MAX IOUT = 0 3/17 GS8721/8722/8724 Electrical Characteristics (At Vs=5V, TA = +25 ℃, V CM = VS/2, RL = 600 Ω, unless otherwise noted.) GS8721/2/4 TYP PARAMETER MIN/MAX OVER TEMPERATURE CONDITIONS ℃ +25 ℃ +25 ℃ to 70℃ 0 ℃ to 85℃ -40 ℃ 125℃ -40 to MIN / UNITS MAX DYNAMIC PERFORMANCE Gain-Bandwidth Product (GBP) RL = 10kΩ, CL = 100pF 11 MHz TYP Phase Margin (φO) RL = 10kΩ, CL = 100pF 51 Degrees TYP Full Power Bandwidth (BWP) ＜1% distortion, R = 600Ω 400 kHz TYP Slew Rate (SR) G = +1, 2V Step, RL = 10kΩ 9 V/µs TYP Settling Time to 0.1% (tS) G = +1, 2V Step, RL = 600Ω 0.3 µs TYP Overload Recovery Time VIN ·Gain = VS, RL = 600Ω 1.5 µs TYP f = 1kHz 11.5 nV / Hz TYP f = 10kHz 8 nV / Hz TYP L NOISE PERFORMANCE Voltage Noise Density (en) V1 4/17 GS8721/8722/8724 Typical Performance characteristics ℃, V (At Vs=5V, TA = +25 CM = VS/2, RL = 600Ω, unless otherwise noted.) Large-Signal Step Response Voltage (500mV/div) Large-Signal Step Response Voltage (1V/div) Vs=5V G=+1 CL=100pF RL=10KΩ Vs=2.5V G=+1 CL=100pF RL=10 KΩ µ µ Small-Signal Step Response Small-Signal Step Response Voltage (50mV/div) Time (1 s/div) Voltage (50mV/div) Time (1 s/div) Vs=5V G=+1 CL=100pF RL=10 KΩ Vs=2.5V G=+1 CL=100pF RL=10 KΩ µ µ Time (1 s/div) Time (1 s/div) Positive Overload Recovery Negative Overload Recovery 50mV VIN RL= 600Ω G=-100 ± 50mV VIN /div ± Vs= 2.5V VIN=50mVp-p Vs= 2.5V VIN=50mVp-p /div RL=600Ω G=-100 1V 0.5V /div VOUT /div VOUT µ µ Time (2 s/div) Time (2 s/div) 5/17 V1 0 GS8721 GS8721/8722/8724 Typical Performance characteristics CM = VS/2, RL = 600Ω, unless otherwise noted.) Vs=5V ℃ 135 ℃ 25 ℃ -5 50 Sinking Current Supply Current (mA) Sourcing Current Supply Current vs. Temperature Vs=2.5 Vs=5 Vs=3 ℃ Output Current(mA) Temperature emperature ( ) Input Voltage Noise Spectral Density vs. Frequency Open Loop Gain, Phase Shift vs. Frequency Vs=5V Open Loop Gain (dB) Voltage Noise (nV/√Hz Output Voltage (V) Output Voltage Swing vs.Output Current Vs=5V CL=100pF RL=10 KΩ Frequency (Hz) Frequency (Hz) CMRR vs. Frequency PSRR vs. Frequency Phase Shift (Degrees) ℃, V (At Vs=5V, TA = +25 PSRR (dB) CMRR (dB) Vs=5V PSRR+ PSRR- Frequency (Hz) V1 Frequency (Hz) 6/17 GS8721/8722/8724 Application Note Size GS872X series op amps are unity-gain stable and suitable for a wide range of general-purpose applications. The small footprints of the GS872X series packages save space on printed circuit boards and enable the design of smaller electronic products. Power Supply Bypassing and Board Layout GS872X 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 1.1mA per channel) of GS872X series will help to maximize battery life. They are ideal for battery powered systems Operating Voltage GS872X series operate 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 GS872X series 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 GS872X series can typically swing to less than 2mV from supply rail in light resistive loads (>100kΩ), and 15mV of supply rail in moderate resistive loads (10kΩ). Capacitive Load Tolerance The GS872X 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 7/17 GS8721/8722/8724 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 8/17 GS8721/8722/8724 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 GS872X. 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 V1 9/17 GS8721/8722/8724 Instrumentation Amplifier The triple GS872X 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 10/17 GS8721/8722/8724 Package Information MSOP-8 V1 11/17 GS8721/8722/8724 SOP-8 V1 12/17 GS8721/8722/8724 SOT23-5 V1 13/17 GS8721/8722/8724 SOT23-6 V1 14/17 GS8721/8722/8724 SC70-5 V1 15/17 GS8721/8722/8724 TSSOP-14 V1 16/17 GS8721/8722/8724 SOP-14 V1 17/17