OPA2170AIDGK - 36V Dual Op Amp, RRO, 1.2MHz | Texas Instruments
MPN: OPA2170AIDGK ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.95 | $1.95 |
| 10 | $1.71 | $17.10 |
| 100 | $1.18 | $118.00 |
| 500 | $0.95 | $475.00 |
| 1,000 | $0.79 | $790.00 |
OPA2170AIDGK Overview
An operational amplifier (op amp) is a high-gain differential voltage amplifier that uses external feedback components to set closed-loop gain, bandwidth, and transfer function. Op amps are fundamental building blocks in analog signal conditioning: they amplify, buffer, filter, sum, and convert signals. Within the broader hierarchy, a dual low-power op amp like the OPA2170 sits below the "linear IC" family, adjacent to instrumentation amplifiers, comparators, and programmable gain amplifiers. The "value line" label from TI indicates it is positioned for cost-sensitive, high-volume designs without sacrificing key specs.
Key features of the OPA2170 include 0.0035 uA input bias current (CMOS input stage), 120 dB CMRR, rail-to-rail output (RRO), an input common-mode range that includes the negative rail, and EMI/RFI filtered inputs to improve immunity in harsh electrical environments. The unity-gain-stable design requires no external compensation and supports capacitive loads up to 1 nF.
Architecturally, the OPA2170 uses a CMOS input stage for high input impedance and low bias current, combined with a class AB output stage that achieves rail-to-rail swing on a single supply. This combination makes the part equally suitable for low-voltage sensor signal chains (where input bias current matters) and higher-voltage industrial loops (where supply tolerance matters).
Typical applications include transducer signal conditioning, 4-20 mA loop drivers, low-side current sensing, active filters, audio signal buffering, general-purpose amplification in PLC analog input modules, and battery-powered instrumentation that needs wide supply tolerance.
When designing in the OPA2170AIDGK, be mindful that although the inputs include the negative rail, the inputs do NOT include the positive rail - common-mode voltage must remain at least a few hundred mV below V+ for linear operation. Use the dual-channel part when two related signals (e.g., a differential sensor) need matched amplifier paths; switch to the quad-channel OPA4170 only when the PCB area savings of one IC outweigh the loss of channel-level routing flexibility.
This page synthesizes distributor pricing, verified cross-reference alternatives in the same VSSOP-8 footprint, and practical design considerations not found in the manufacturer datasheet alone.
Drop-in alternatives for OPA2170AIDGK — 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:
OPA2170AIDGKR
✅ Drop-In📋 Reference alternative (not in catalog)
OPA2171AIDGK
✅ Drop-In📋 Reference alternative (not in catalog)
OPA2170AIDGKT
✅ Drop-In📋 Reference alternative (not in catalog)
OPA2170AIDGK Maximum Ratings & Electrical Characteristics
| Number of Channels | 2 (Dual) |
| Amplifier Type | General Purpose, Low Power |
| Gain Bandwidth Product | 1.2 MHz |
| Slew Rate | 0.4 V/us |
| Supply Voltage Range (Single) | 2.7 V to 36 V |
| Supply Voltage Range (Dual) | +/-1.35 V to +/-18 V |
| Quiescent Current (per channel) | 110 uA (typ) |
| Input Bias Current (IBIAS) | 0.0035 uA |
| CMRR | 120 dB |
| Input Voltage Noise Density | 19 nV/sqrt(Hz) |
| Common-Mode Input Range | Includes negative rail (V-) |
| Output Swing | Rail-to-rail (RRO) |
| Operating Temperature | -40 C to +125 C |
| Package | VSSOP-8 (DGK) - MSOP-8 |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
OPA2170AIDGK Pin Configuration
| Pin 1 | OUT_A / OUT1 — Channel A / channel 1 output |
| Pin 2 | IN- A / IN-1 — Channel A inverting input |
| Pin 3 | IN+ A / IN+1 — Channel A non-inverting input |
| Pin 4 | V- / GND — Negative supply (or ground for single supply) |
| Pin 5 | IN+ B / IN+2 — Channel B non-inverting input |
| Pin 6 | IN- B / IN-2 — Channel B inverting input |
| Pin 7 | OUT_B / OUT2 — Channel B / channel 2 output |
| Pin 8 | V+ / VCC — Positive supply |
Typical Applications
OPA2170AIDGK is suitable for 7 applications: Transducer Signal Conditioning, 4-20 mA Current Loop Receiver, Low-Side Current Sensing, Active Filter Building Block, Audio Signal Buffering, Battery-Powered Sensor Node, PLC Analog Input Module.
Transducer Signal Conditioning
The OPA2170AIDGK is well suited to amplify low-level signals from bridge, thermocouple, and piezoelectric transducers. With input bias current at just 3.5 pA and input voltage noise of 19 nV/sqrt(Hz), it does not load the high-impedance source or add appreciable noise to the measurement, while 120 dB CMRR rejects common-mode pickup from long sensor leads in industrial environments.
Recommended
4-20 mA Current Loop Receiver
In a 4-20 mA current-loop receiver, the OPA2170AIDGK forms the front-end buffer/amplifier that converts the loop current into a 1-5 V signal at the ADC input. Its 36 V supply tolerance directly handles loop-powered industrial supplies, the 0.4 V/us slew rate catches loop step responses, and the rail-to-rail output maximizes dynamic range across the 3.3 V / 5 V ADC full-scale. Two channels on one IC enable redundant-loop or differential-loop topologies.
Recommended
Low-Side Current Sensing
The OPA2170AIDGK is an excellent choice for low-side current-sensing in motor drives, solenoid drivers, and battery packs. Its input range includes the negative supply rail, so the op amp can sense voltages right at the low-side shunt (V- to V- + 0.2 V common mode), and the rail-to-rail output maximizes swing into the ADC. The 36 V supply tolerance handles 24 V industrial bus transients.
Recommended
Active Filter Building Block
Designers can build Sallen-Key, multiple-feedback (MFB), and state-variable active filters using the OPA2170AIDGK. Its 1.2 MHz GBWP is sufficient for filters up to several hundred kHz, the unity-gain-stable design needs no compensation, and the low 19 nV/sqrt(Hz) input noise keeps filter noise floor low. Two channels on one chip simplify stereo or quadrature filter stages.
Recommended
Audio Signal Buffering
For line-level audio signal buffering and pre-amplification, the OPA2170AIDGK provides 19 nV/sqrt(Hz) noise and rail-to-rail output swing from a single 5 V supply - more than enough dynamic range for consumer audio. The two channels easily handle stereo source switching or headphone-driver preamp stages, while 0.4 V/us slew rate covers full-range audio with substantial margin.
Recommended
Battery-Powered Sensor Node
The OPA2170AIDGK's 110 uA per-channel quiescent current extends battery life in portable sensor nodes such as wireless environmental monitors, IoT gas detectors, and handheld meters. Its 2.7 V minimum supply lets it run directly off a single Li-ion or two alkaline cells, while the 36 V maximum allows hot-plugging into higher-voltage test fixtures without damage.
Recommended
PLC Analog Input Module
In a Programmable Logic Controller (PLC), the OPA2170AIDGK functions as the input buffer / attenuator for analog inputs, including voltage-mode and current-mode channels. Its 36 V supply tolerates 24 V field wiring, the EMI/RFI filtered inputs survive noisy industrial environments, and the rail-to-rail output maximizes ADC resolution on the multiplexed input. Two channels per IC enable dual analog inputs in tight PLC-form-factor designs.
Recommended
Recommended Products Summary
Engineering reference data for OPA2170AIDGK — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA2170AIDGKR | OPA2171AIDGK | OPA2170AIDGKT | OPA2170AID |
|---|---|---|---|---|---|
| Package | VSSOP-8 (DGK) | VSSOP-8 (DGK) - same | VSSOP-8 (DGK) - same | VSSOP-8 (DGK) - same | SOIC-8 (D) - different footprint |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Channels | 2 (Dual) | 2 (Dual) | 2 (Dual) | 2 (Dual) | 4 (Quad) |
| Gain Bandwidth Product | 1.2 MHz | 1.2 MHz | ~3 MHz | 1.2 MHz | 1.2 MHz |
| Supply Voltage Range | 2.7 V to 36 V | 2.7 V to 36 V | 2.7 V to 36 V | 2.7 V to 36 V | 2.7 V to 36 V |
| Slew Rate | 0.4 V/us | 0.4 V/us | ~1.5 V/us | 0.4 V/us | 0.4 V/us |
| Quiescent Current (per channel) | 110 uA | 110 uA | Higher | 110 uA | 110 uA |
| Output Swing | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail |
Key Differentiators
- Lowest quiescent current in TI's 36 V value-line dual op amp family (vs OPA2171AIDGK)
- Direct 24 V industrial compatibility with single-supply operation (vs TL072)
- CMOS input stage with sub-nA bias current (vs LM358)
Design Notes
Estimated: although the OPA2170AIDGK common-mode range includes the negative supply rail, it does NOT include the positive rail. Engineers commonly misread this from the datasheet front page and try to use the part on unity-gain buffer of a 5 V signal with a 5 V single supply. Always leave at least 1.5 V to 2 V between the input common-mode voltage and V+ to stay within linear operation. For rail-rail-input applications, choose the OPA2192 instead.
When laying out the VSSOP-8 / MSOP-8 footprint, place a 0.1 uF ceramic bypass capacitor as close as possible to the V+ pin (pin 8), with the loop back to pin 4 (V-) traced over a short, wide ground pour. Avoid routing the inverting and non-inverting inputs as parallel, long traces - large parallel sections create a parasitic differential-mode capacitance that adds poles and can destabilize the feedback loop. Use a ground plane on layer 2 of a 4-layer board.
Estimated: assuming 12 V single supply, VOUT = 5 V at 1 mA load, the OPA2170AIDGK dissipates about 7 mW per channel - well within thermal limits. At higher load currents (e.g., 20 mA into 200 ohm) and 36 V supply, dissipation rises to ~620 mW per channel, and the MSOP-8 thermal pad (theta_JA ~ 200 C/W on a small 2-layer board) can allow junction temperatures to climb >125 C above ambient. For high-load designs, switch to the SOIC-8 OPA2170AID variant, which has substantially lower theta_JA.
If the OPA2170AIDGK is driving an ADC sample-and-hold input, insert a 10 ohm to 100 ohm series resistor between the op-amp output and the ADC input. The resistor isolates the op-amp output stage capacitance from the ADC's switched-capacitor input, preventing ringing and limiting fault currents at ADC sample events. Together with a 1 nF to 10 nF capacitor at the ADC input, this forms a one-pole RC filter that improves SNR.
Compliance Information
RoHS compliant per TI product page (DGK suffix denotes lead-free MSOP). The OPA2170AIDGK is not AEC-Q100 qualified; for automotive use, choose the OPA2170AIDGK-Q1 variant.
