GS8331/8332/8334
350KHZ Zero-Drift CMOS Rail-to-Rail IO Opamp with RF Filter
Features
·
Single-Supply Operation from +1.8V ~ +5.5V
·
Embedded RF Anti-EMI Filter
·
Rail-to-Rail Input / Output
·
Small Package:
·
Gain-Bandwidth Product: 350KHz (Typ. @25°C)
GS8331 Available in SOT23-5, SC-70 and SOP-8
·
Low Input Bias Current: 20pA (Typ. @25°C)
Packages
·
Low Offset Voltage: 10uV (Max. @25°C)
GS8332 Available in SOP-8, MSOP-8 and DFN-8
·
Quiescent Current: 25μA per Amplifier (Typ.)
Packages
·
Operating Temperature: -45°C ~ +125°C
GS8334 Available in SOP-14 and TSSOP-14 Packages
·
Zero Drift: 0.03µV/°C (Max.)
General Description
The GS833X amplifier is single/dual/quad supply, micro-power, zero-drift CMOS operational amplifiers, the amplifiers offer
bandwidth of 350 kHz, rail-to-rail inputs and outputs, and single-supply operation from 1.8V to 5.5V. GS833X uses chopper
stabilized technique to provide very low offset voltage (less than 10µV maximum) and near zero drift over temperature. Low
quiescent supply current of 25μA 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 GS833X 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 GS8331 is available in SOT23-5, SC-70 and SOP8 packages. And the GS8332 is available in SOP8, MSOP8 and DFN-8
packages. The GS8334 Quad is available in Green SOP-14 and TSSOP-14 packages. The extended temperature range of
o
o
-45 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
Figure 1. Pin Assignment Diagram
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GS8331/8332/8334
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
-45°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)
+150°C
+260°C
Package Thermal Resistance (TA=+25℃)
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.
Package/Ordering Information
MODEL
GS8331
GS8332
GS8334
V1
CHANNEL
Single
Dual
Quad
PACKAGE
PACKAGE
MARKING
DESCRIPTION
OPTION
INFORMATION
GS8331-TR
SOT23-5
Tape and Reel,3000
8331
GS8331Y-TR
SOT23-5
Tape and Reel,3000
8331Y
GS8331-CR
SC70-5
Tape and Reel,3000
8331
GS8331-SR
SOP-8
Tape and Reel,4000
GS8331
GS8332-SR
SOP-8
Tape and Reel,4000
GS8332
GS8332-MR
MSOP-8
Tape and Reel,3000
GS8332
GS8332-FR
DFN-8
Tape and Reel,3000
GS8332
GS8334-TR
TSSOP-14
Tape and Reel,3000
GS8334
GS8334-SR
SOP-14
Tape and Reel,2500
GS8334
ORDER NUMBER
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GS8331/8332/8334
Electrical Characteristics
(At Vs=5V, TA = +25℃, VCM = VS/2, RL = 10KΩ, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Offset Voltage (VOS)
2
10
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
50
nV/℃
RL = 100kΩ to - VS
4.998
V
RL = 10kΩ to - VS
4.994
V
RL = 100kΩ to + VS
5
mV
RL = 10kΩ to + VS
20
mV
RL =10Ω to - VS
20
mA
30
mA
INPUT CHARACTERISTICS
Common-Mode
Rejection
Ratio
(CMRR)
Large Signal Voltage Gain ( AVO)
Input Offset Voltage Drift (ΔVOS/ΔT)
OUTPUT CHARACTERISTICS
Output Voltage High (VOH)
Output Voltage Low (VOL)
Short Circuit Limit (ISC)
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
25
μA
Gain-Bandwidth Product (GBP)
G = +100
350
KHz
Slew Rate (SR)
RL = 10kΩ
0.2
V/μs
Voltage Noise (en p-p)
0Hz to 10Hz
1.1
μVP-P
Voltage Noise Density (en)
f = 1kHz
70
nV / Hz
DYNAMIC PERFORMANCE
NOISE PERFORMANCE
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GS8331/8332/8334
Typical Performance characteristics
(TA=+25°C, Vs=5V, RL=10 kΩ connected to VS/2 and VOUT= VS/2, unless otherwise noted.)
Output Voltage (50mV/div)
CL=0pF
G=+1
Large Signal Transient Response
CL=0pF
G=+1
Time(40µs/div)
Time(4µs/div)
Positive Overvoltage Recovery
Negative Overvoltage Recovery
VSY=±2.5V
VIN=-200mVp-p
(RET to GND)
CL=0pF
RL=10kΩ
AV=-10
Output Voltage (50mV/div)
Output Voltage (1V/div)
Large Signal Transient Response
VSY=±2.5V
VIN=-200mVp-p
(RET
to
GND)
CL=0pF
RL=10kΩ
AV=-10
Time (50µs/div)
Time (50µs/div)
Open Loop Gain, Phase Shift vs. Frequency
Supply Current vs. Temperature
Open Loop Gain
Frequency (Hz)
V1
Supply Current (µA)
Open Loop Gain (dB)
Phase Shift
VS=5.5V
Vs=1.8V
Temperature (℃)
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GS8331/8332/8334
Typical Performance characteristics
(TA=+25°C, Vs=5V, RL=10 kΩ connected to VS/2 and VOUT= VS/2, unless otherwise noted.)
Output Voltage Swing vs.Output Current at +3V
Output Voltage Swing vs.Output Current at +5V
125℃ 25℃
-40℃
Sinking Current
Output Current(mA)
V1
Sourcing Current
Output Voltage (V)
Output Voltage (V)
Sourcing Current
125℃ 25℃
-40℃
Sinking Current
Output Current(mA)
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GS8331/8332/8334
Application Note
Size
GS833X series op amps are unity-gain stable and suitable for a wide range of general-purpose applications. The small
footprints of the GS833X series packages save space on printed circuit boards and enable the design of smaller electronic
products.
Power Supply Bypassing and Board Layout
GS833X series operates from a single 1.8V to 5.5V supply or dual ±0.9V 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 25uA per channel) of GS833X series will help to maximize battery life. They are ideal for battery
powered systems
Operating Voltage
GS833X series operate under wide input supply voltage (1.8V to 5.5V). In addition, all temperature specifications apply from
o
o
-45 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 GS833X 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 GS833X series can typically swing to less than 5mV from supply rail in
light resistive loads (>100kΩ), and 100mV of supply rail in moderate resistive loads (10kΩ).
Capacitive Load Tolerance
The GS833x 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
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GS8331/8332/8334
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.
CF
RF
-
RISO
VOUT
VIN
+
CL
RL
Figure 3. Indirectly Driving a Capacitive Load with DC Accuracy
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GS8331/8332/8334
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 GS833X.
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
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GS8331/8332/8334
Instrumentation Amplifier
The triple GS833X 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
.
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GS8331/8332/8334
Package Information
DFN-8
V1
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SOP-8
V1
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MSOP-8
V1
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SOT23-5
V1
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SC70-5
V1
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SOP-14
V1
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TSSOP-14
V1
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