SGM8955XN5G - Zero-Drift Op Amp, 1-Ch, SOT-23-5 | SG Micro
MPN: SGM8955XN5G ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.33 | $0.33 |
| 10 | $0.3 | $3.00 |
| 100 | $0.26 | $26.00 |
| 500 | $0.22 | $110.00 |
| 1,000 | $0.18 | $180.00 |
SGM8955XN5G Overview
An operational amplifier (op amp) is a high-gain differential DC amplifier that uses external feedback components to set gain, bandwidth, and transfer characteristics. Zero-drift op amps employ either chopper or auto-zero (chopper-stabilized) architectures to continuously correct offset voltage, eliminating the 1/f flicker noise and offset drift that plague conventional CMOS and bipolar input stages. The SGM8955 belongs to the precision amplifier category within the broader linear IC hierarchy: operational amplifier → amplifier IC → analog signal chain → semiconductor.
Key features of the SGM8955XN5G include a 20 µA typical quiescent supply current, 180 V/ms slew rate, rail-to-rail input and rail-to-rail output (RRIO) swing, EMI filtering/RF suppression on the inputs, and an integrated auto-zero calibration loop. The SOT-23-5 (XN5) package operates across -40 °C to +125 °C and supports supply voltages suitable for 2.7 V-5.5 V single-supply systems. The combination of low offset, low drift, low power, and RRIO makes the part a strong fit for battery-powered instrumentation, transducer conditioning, and precision ADC front ends.
The SGM8955/6 architecture uses a chopper-stabilized CMOS input stage to achieve sub-50 µV offset, eliminating the periodic recalibration required by conventional CMOS amplifiers in precision applications. The internal EMI/RF input filter rejects high-frequency interference, simplifying PCB layout for sensor applications in electrically noisy environments. The 20 µA quiescent current and low shutdown leakage allow the part to remain continuously powered in battery applications without significantly reducing runtime.
Typical applications include high-precision ADC driver circuits, weigh scale and strain gauge signal conditioning, thermocouple and bridge sensor amplifiers, portable medical instrumentation, battery-powered industrial sensors, and zero-drift transducer interfaces. The RRIO capability allows the part to operate at unity gain in single-supply systems where input and output signals swing close to either supply rail.
When designing with the SGM8955XN5G, place the input capacitor as close to the op-amp input pins as possible, ensure the feedback network uses 1% or better resistors to maintain gain accuracy, and add an anti-aliasing RC network at the output when driving a downstream ADC. Estimated: total supply current is the sum of the 20 µA quiescent plus the load-dependent output stage current.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for SGM8955XN5G — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
SGM8956XN5G/TR
✅ Drop-In📋 Reference alternative (not in catalog)
SGM8955XMS8G/TR
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
OPA333AIDBVR
✅ Drop-In✓ In Stock
$0.1685 / Unit
View Datasheet →MCP6V31T-E/OT
✅ Drop-In📋 Reference alternative (not in catalog)
ADA4522-1ARMZ
✅ Drop-In📋 Reference alternative (not in catalog)
LPV821DBVR
✅ Drop-In📋 Reference alternative (not in catalog)
SGM8955XN5G Maximum Ratings & Electrical Characteristics
| Number of Channels | 1 |
| Amplifier Type | Zero-Drift / Auto-Zero |
| Offset Voltage (MAX) | 22 µV |
| Offset Voltage Drift | 80 nV/°C |
| Open-Loop Gain | 100 dB |
| Input Bias Current | 130 pA |
| Quiescent Current (typ) | 20 µA |
| Slew Rate | 180 V/ms |
| Input/Output Swing | Rail-to-Rail Input, Rail-to-Rail Output |
| Input Type | CMOS, high impedance |
| EMI/RF Filtering | Yes (EMI filtering/RF suppression) |
| Package | SOT-23-5 (XN5) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 °C to +125 °C |
| RoHS Status | Compliant (Green package) |
SGM8955XN5G Pin Configuration
| Pin 1 | OUT — Amplifier output |
| Pin 2 | V- — Negative power supply (ground) |
| Pin 3 | IN+ — Non-inverting input |
| Pin 4 | V- — Negative power supply (ground) |
| Pin 5 | IN- — Inverting input |
Typical Applications
SGM8955XN5G is suitable for 7 applications: Precision ADC Driver, Weigh Scale and Strain Gauge Signal Conditioning, Thermocouple and Cold-Junction Amplifier, Portable Medical Instrumentation, Battery-Powered Industrial Sensor Interface, Handheld Meter and Test Equipment Front End, Photodiode and Optical Sensor Transimpedance Amplifier.
Precision ADC Driver
The SGM8955XN5G's 22 µV (MAX) offset voltage, 80 nV/°C drift, and rail-to-rail input/output swing make it an ideal driver for 16-bit to 24-bit SAR and delta-sigma ADCs in precision data acquisition front ends. Driving the ADC reference or input buffer with the SGM8955XN5G reduces system offset error, while its 180 V/ms slew rate settles quickly between conversions. The built-in EMI filtering/RF suppression protects against high-frequency interference from switching converters on the same PCB, which is critical in industrial data-acquisition boards where digital clocks couple into analog rails. Place the SGM8955XN5G within 5 mm of the ADC input pins with a 10 nF anti-aliasing RC network at the output.
Recommended
Weigh Scale and Strain Gauge Signal Conditioning
Bridge sensors in weigh scales and force measurement systems require micro-volt-level signal conditioning where the 22 µV (MAX) offset and 80 nV/°C drift of the SGM8955XN5G directly determine system accuracy. Used as an instrumentation front end, the SGM8955XN5G drives a low-side current source and amplifies the millivolt-level bridge output with gain set by precision 0.1% resistors. Unlike a generic op amp, its zero-drift auto-zero architecture eliminates 1/f flicker noise and periodic recalibration needed for long-term weighing stability. The 20 µA quiescent current lets battery-powered scales remain idle without depleting the cell.
Recommended
Thermocouple and Cold-Junction Amplifier
Thermocouple amplifiers require sub-50 µV offset and nano-volt drift to resolve sub-degree Celsius temperature differences, which the SGM8955XN5G provides through its 22 µV (MAX) offset and 80 nV/°C drift. Placed between a K-type or T-type thermocouple and a 24-bit ADC, the SGM8955XN5G buffers the low-level thermocouple voltage with high impedance (130 pA input bias current) to minimize source loading. The rail-to-rail input allows single-supply operation from common 3.3 V or 5 V rails without the negative supply required by older op amps, simplifying battery-powered temperature loggers. The chopper-stabilized input rejects 1/f flicker noise that would otherwise dominate sub-Hz temperature signals.
Recommended
Portable Medical Instrumentation
Battery-powered medical devices such as glucose meters, pulse oximeters, and bedside monitors rely on low-power precision op amps, and the SGM8955XN5G delivers 22 µV (MAX) offset with 20 µA quiescent current - ideal for continuous biosignal conditioning without draining the cell. The chopper-stabilized auto-zero architecture eliminates periodic recalibration that hospital equipment cannot afford. Rail-to-rail input/output allows the part to operate at unity gain in 2.7 V-5.5 V single-supply designs where signals swing close to either rail, while built-in EMI filtering rejects RF interference from mobile phones and wireless patient monitors. The -40 °C to +125 °C operating range covers clinical and field-deployed use cases.
Recommended
Battery-Powered Industrial Sensor Interface
Wireless sensor nodes and IoT edge devices require precision analog front ends that consume minimal current, and the SGM8955XN5G delivers 20 µA quiescent current with 22 µV offset - perfect for amplifying 4-20 mA loop signals, RTD sensors, and thermocouples in battery-powered field instruments. The rail-to-rail input and output operate from 2.7 V to 5.5 V single supplies, eliminating the boost converter that would otherwise be required by older non-RRIO amplifiers. The EMI filtering/RF suppression on the inputs rejects interference from switching regulators and RF transmitters co-located on the same PCB. The -40 °C to +125 °C operating range covers outdoor industrial deployments.
Recommended
Handheld Meter and Test Equipment Front End
Digital multimeters, LCR meters, and handheld oscilloscope probes require low-offset, low-drift precision amplifiers, and the SGM8955XN5G's 22 µV (MAX) offset, 80 nV/°C drift, and 180 V/ms slew rate support high-accuracy measurement at high scan rates. The RRIO capability allows direct connection to single-supply 3.3 V ADCs without signal loss at the rails. The 100 dB open-loop gain ensures gain accuracy better than 0.001% in closed-loop configurations, while the 130 pA input bias current minimizes loading of high-impedance probes. The SOT-23-5 footprint fits compact handheld form factors where PCB area is constrained.
Recommended
Photodiode and Optical Sensor Transimpedance Amplifier
Photodiode transimpedance amplifiers (TIAs) for light sensors, position detectors, and optical encoders benefit from the SGM8955XN5G's 130 pA input bias current, which is low enough to handle silicon photodiodes producing nanoamp-level currents without significant loading error. The chopper-stabilized zero-drift architecture eliminates the 1/f flicker noise that would otherwise dominate low-frequency optical measurements. The 180 V/ms slew rate supports pulsed-light measurements and high-speed encoder signals. The rail-to-rail output swings within millivolts of either supply rail, maximizing dynamic range in 3.3 V single-supply systems.
Recommended
Recommended Products Summary
Engineering reference data for SGM8955XN5G — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | SGM8956XN5G/TR | OPA333AIDBVR | MCP6V31T-E/OT | ADA4522-1ARMZ | LPV821DBVR |
|---|---|---|---|---|---|---|
| Brand | SG Micro | SG Micro | Texas Instruments | Microchip Technology | Analog Devices | Texas Instruments |
| Package | SOT-23-5 (XN5) | SOT-23-5 (XN5) - same | SOT-23-5 (DBV) - same | SOT-23-5 - same | SOT-23-5 (alternative MSOP-8) | SOT-23-5 (DBV) - same |
| Number of Channels | 1 | 2 (dual) | 1 | 1 | 1 | 1 |
| Rail-to-Rail I/O | Yes (RRIO) | Yes (same die) | Yes (RRIO) | Yes (RRIO) | Yes (RRIO) | Yes (RRIO) |
| EMI/RF Filtering | Yes | Yes (same die) | No (external filter required) | No (external filter required) | No (external filter required) | Yes |
| Operating Temperature | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C | -40 °C to +125 °C |
Key Differentiators
- Built-in EMI/RF input filtering on the SOT-23-5 footprint (vs OPA333AIDBVR)
- Better offset voltage than the SGM8955 dual version's single-channel use case (vs SGM8956XN5G/TR)
- Lower quiescent current than the SGM8955 in nanopower applications (vs LPV821DBVR)
- Lower offset voltage than the OPA333 in cost-sensitive designs (vs OPA333AIDBVR)
Design Notes
Place the SGM8955XN5G within 5 mm of the input signal source and use a 4-layer PCB with a continuous ground plane to minimize parasitic inductance on the V- pin (pins 2 and 4). Both V- pins must be tied together on the PCB. Add 0.1 µF X7R ceramic bypass capacitors within 2 mm of the supply pin to suppress high-frequency noise from digital circuitry. The chopper-stabilized architecture is sensitive to supply ripple, so place the bypass capacitor directly between pin 2/4 and pin 5/V- plane.
Do not assume pin 2 and pin 4 are independent V- pins - they must both be tied to ground on the PCB; leaving either floating creates instability. The chopper-stabilized input draws charge injection currents at the switching frequency; add a small RC filter (10 kΩ + 1 nF) at the input when driving high-impedance sources to filter the chopping ripple. Estimated: chopping frequency is typically 10-50 kHz depending on supply voltage - the RC cutoff should be set well below this to reject ripple without filtering the signal.
Use 0.1% metal-film or thin-film resistors in the feedback network to maintain gain accuracy better than 0.01%, which matters for ADC driver applications. Add a 10 pF to 100 pF feedback capacitor in parallel with the feedback resistor when the closed-loop gain is greater than 10 - this compensates for the input capacitance and prevents peaking at the gain-bandwidth product. The SGM8955XN5G's RRIO output swings within 50 mV of either rail at 1 mA load, so design the downstream ADC reference with adequate headroom.
Route sensitive analog input traces on an inner layer with ground shielding on both sides, or use a top-layer trace with guard rings tied to V-. Avoid routing digital clock or switching-converter traces parallel to analog input lines; if unavoidable, separate by at least 3x the trace width. For weigh-scale and strain-gauge applications, use a Kelvin connection to the bridge sensor to eliminate IR drop in the excitation traces. Estimated: at 1 mA bridge current, a 0.1 Ω trace resistance creates 100 µV of offset error - this is the same magnitude as the SGM8955XN5G's own offset, so PCB layout is critical.
Compliance Information
RoHS compliant (Green package) per SG Micro product page. Lead-free and halogen-free per the LCSC and JLCPCB datasheets. Not AEC-Q100 qualified - choose an automotive-grade alternate such as MCP6V31T-E/OT if automotive qualification is required.
