OPA404KP - Quad Difet Op Amp 6.4MHz 35V/us | Texas Instruments
MPN: OPA404KP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $29.08 | $29.08 |
| 10 | $27.5 | $275.00 |
| 100 | $26.2 | $2,620.00 |
| 500 | $25.1 | $12,550.00 |
| 1,000 | $23.9 | $23,900.00 |
Drop-in alternatives for OPA404KP — 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:
OPA404KPG4
✅ Drop-In📋 Reference alternative (not in catalog)
TLE2074CN
✅ Drop-In📋 Reference alternative (not in catalog)
TL074ACN
✅ Drop-In📋 Reference alternative (not in catalog)
OPA404KP Maximum Ratings & Electrical Characteristics
| Amplifier Type | Quad High-Speed Precision Difet Operational Amplifier |
| Number of Circuits | 4 |
| Gain Bandwidth Product | 6.4 MHz |
| Slew Rate | 35 V/us |
| Input Offset Voltage (max) | +/-750 uV |
| Input Bias Current (max) | +/-4 pA |
| Settling to 0.01% | 0.01% settling spec (datasheet value) |
| Total Supply Voltage (min) | 10 V |
| Total Supply Voltage (max) | 36 V |
| Supply Type | Dual or single supply |
| Package | 14-PDIP |
| Mounting Type | Through Hole |
| Input Type | Difet (FET input, cascode) |
| Pin Configuration | Standard quad op amp pinout |
| Manufacturer Series | OPA404 |
| Product Status | Active |
OPA404KP Pin Configuration
| Pin 1 | OUT1 — Amplifier 1 output |
| Pin 2 | IN1- — Amplifier 1 inverting input |
| Pin 3 | IN1+ — Amplifier 1 non-inverting input |
| Pin 4 | V+ — Positive supply |
| Pin 5 | IN2+ — Amplifier 2 non-inverting input |
| Pin 6 | IN2- — Amplifier 2 inverting input |
| Pin 7 | OUT2 — Amplifier 2 output |
| Pin 8 | OUT3 — Amplifier 3 output |
| Pin 9 | IN3- — Amplifier 3 inverting input |
| Pin 10 | IN3+ — Amplifier 3 non-inverting input |
| Pin 11 | V- — Negative supply |
| Pin 12 | IN4+ — Amplifier 4 non-inverting input |
| Pin 13 | IN4- — Amplifier 4 inverting input |
| Pin 14 | OUT4 — Amplifier 4 output |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
OPA404KP is suitable for 6 applications: Data Acquisition Front Ends, Photodiode Transimpedance Amplifiers, Active Filter Networks, Instrumentation Signal Chains, Sample-and-Hold and Peak Detectors, Audio and Professional Signal Processing.
Data Acquisition Front Ends
The OPA404KP fits multi-channel data acquisition systems because it provides four matched amplifiers with ±750uV maximum offset and 0.01% settling in one 14-PDIP package. Channel-to-channel matching on a single Difet die reduces calibration burden versus four discrete amplifiers, while the 6.4MHz bandwidth and 35V/us slew rate support fast settling ahead of successive-approximation ADCs. Used as unity-gain buffers or gain-of-10 stages between signal conditioning networks and the ADC driver, it preserves DC accuracy without sacrificing speed. The ±4pA maximum bias current keeps source loading negligible even with high-impedance inputs.
Recommended
Photodiode Transimpedance Amplifiers
In transimpedance amplifiers, error is dominated by input bias current flowing through the large feedback resistor; the OPA404KP's ±4pA maximum bias current (Difet input) keeps this error minimal, enabling megohm-range feedback resistors for low-light detection. The 6.4MHz bandwidth and 35V/us slew rate accommodate fast photodiode pulses in optical receivers and pulse-detection systems. A quad package allows four parallel detector channels with matched characteristics, simplifying ratiometric measurements. Compensation across the feedback element is straightforward given the amplifier's stable unity-gain behavior and moderate bandwidth.
Recommended
Active Filter Networks
Four amplifier channels in one package make the OPA404KP efficient for state-variable and multiple-feedback active filters, where each pole-pair typically consumes two op amps. The 6.4MHz gain-bandwidth exceeds the classical 100x rule-of-thumb margin for audio-band and low-MHz filters, minimizing Q distortion and corner-frequency error. Low ±750uV offset keeps DC offsets through cascaded filter sections controlled, and the ±4pA input current allows large-value precision resistors that shrink capacitor sizes. Standard quad pinout permits direct substitution into legacy TL074-based filter boards with immediate precision gains.
Recommended
Instrumentation Signal Chains
Bench and industrial instrumentation requires amplifiers combining DC accuracy with bandwidth, and the OPA404KP delivers both: ±750uV maximum offset, 0.01% settling, 6.4MHz bandwidth, and 35V/us slew rate in a 10V-36V total supply envelope compatible with ±15V analog rails. Four matched channels support simultaneous multi-parameter measurement front ends. The Difet input cascode preserves precision at speed, unlike commodity JFET quads that degrade accuracy at high frequencies. For instrumentation-instrument upgrades, the standard quad pinout enables drop-in socket replacement of legacy amplifiers without PCB redesign.
Recommended
Sample-and-Hold and Peak Detectors
Sample-and-hold circuits demand amplifiers with rapid slew to acquire signals plus extremely low input current so the hold capacitor does not droop. The OPA404KP addresses both: 35V/us slew rate shortens acquisition time, while ±4pA maximum bias current minimizes hold-capacitor discharge, supporting microsecond hold periods with modest capacitance values. The 0.01% settling specification ensures the held value is accurate to 10-bit-plus precision. Quad packaging allows a full four-channel sample-hold array on a single IC, improving channel matching in simultaneous-sampling systems.
Recommended
Audio and Professional Signal Processing
For high-end audio processing, the OPA404KP's quad format provides matched channels for stereo plus auxiliary paths, while the Difet input yields negligible bias-current-induced pops and DC offsets through coupling capacitors. The 6.4MHz bandwidth and 35V/us slew rate ensure full fast-rise transient reproduction with ample dynamic headroom, avoiding slew-induced distortion on high-amplitude high-frequency content. Offset of ±750uV max keeps DC at outputs low enough for direct-coupled designs with muting FETs. Designers upgrade legacy TL074ACN quad sockets with this part for an audible-accuracy improvement without layout changes.
Recommended
Recommended Products Summary
Engineering reference data for OPA404KP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA404KPG4 | TLE2074CN | TL074ACN | OPA404KU |
|---|---|---|---|---|---|
| Package | 14-PDIP | 14-PDIP - same | 14-PDIP - same | 14-PDIP - same | SOIC-14 (different, SMT) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Gain-Bandwidth | 6.4 MHz | 6.4 MHz | 9.4 MHz | 3 MHz | 6.4 MHz |
| Slew Rate | 35 V/us | 35 V/us | 35 V/us | 13 V/us | 35 V/us |
| Max Input Offset Voltage | +/-750 uV | +/-750 uV | [DATA_NEEDED] | [DATA_NEEDED] | +/-750 uV |
| Max Input Bias Current | +/-4 pA | +/-4 pA | [DATA_NEEDED] | [DATA_NEEDED] | +/-4 pA |
| Total Supply Range | 10 V to 36 V | 10 V to 36 V | 10 V to 36 V | 10 V to 36 V | 10 V to 36 V |
| Number of Channels | 4 | 4 | 4 | 4 | 4 |
| Precision Class | Precision Difet (0.01% settling) | Precision Difet (identical) | General-purpose JFET | General-purpose JFET | Precision Difet (identical) |
Key Differentiators
- Precision Difet input with ±4pA max bias current in a quad (vs TL074ACN)
- 0.01% settling specified (vs TLE2074CN)
- Standard quad pinout upgrade path (vs TL074ACN)
Design Notes
The OPA404KP requires a total supply of 10V to 36V and does not support rail-to-rail inputs or outputs - ensure input common-mode and output swing remain within the linear region defined in the manufacturer datasheet, especially on +/-9V minimum rails where headroom is tightest. Decouple each supply pin (pin 4 V+, pin 11 V-) with 0.1uF ceramic capacitors placed within a few millimeters of the PDIP, plus one 10uF bulk capacitor per board. On quad amplifiers, all four channels share the supply pins, so four-channel simultaneous switching can couple through the supply impedance.
Even in through-hole PDIP, precision matters: keep input traces short and guard high-impedance nodes (photodiode anodes, summing junctions) with a driven guard ring tied to the input's reference potential to exploit the ±4pA bias current spec. Leakage across the PCB can easily exceed picoampere bias current, so clean flux residue thoroughly or conformal-coat the input area. Ground the unused channels of a quad in a stable configuration (unity-gain follower with input at mid-supply) rather than leaving inputs floating.
Do not assume the OPA404KP is a simple TL074 substitute despite the identical pinout: its precision Difet input is more sensitive to electrostatic damage and PCB leakage, and its minimum 10V total supply rules out 5V single-supply operation. Verify the settling-time specification under your actual gain, load capacitance, and feedback network - datasheet 0.01% settling is measured under specific conditions. When driving significant capacitive loads, add an isolation resistor or a BUF634 buffer to avoid instability.
Compliance Information
Compliance status for the OPA404KP was not found in the provided verified data. The G4-suffixed variant (OPA404KPG4) is TI's standard marking for RoHS-compliant builds; confirm current status on the TI product page before design-in.
