OPA828IDR - 45MHz JFET Op Amp, 4nV/√Hz | TI | Precision Amplifier
MPN: OPA828IDR ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.95 | $4.95 |
| 10 | $4.45 | $44.50 |
| 100 | $3.96 | $396.00 |
| 500 | $3.55 | $1,775.00 |
| 1,000 | $3.17 | $3,170.00 |
Drop-in alternatives for OPA828IDR — 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:
OPA827
✅ Drop-In✓ In Stock
$2.88 / Unit
View Datasheet →OPA627
✅ Drop-In✓ In Stock
$7.9 / Unit
View Datasheet →AD8610ARZ
✅ Drop-In📋 Reference alternative (not in catalog)
OPA828IDR Maximum Ratings & Electrical Characteristics
| Amplifier Type | JFET-Input Operational Amplifier |
| Number of Channels | 1 |
| Gain Bandwidth Product | 45 MHz |
| Slew Rate | 150 V/us |
| Input Voltage Noise Density | 4 nV/sqrt(Hz) at 1 kHz |
| Input Voltage Noise (0.1 Hz to 10 Hz) | 60 nVRMS |
| Input Bias Current | 1 pA (typ) |
| Input Offset Voltage | 50 uV |
| Input Offset Drift | 0.45 uV/C (typ) |
| Supply Voltage Range | ±4 V to ±18 V (36 V total) |
| Output Type | Rail-to-Rail Output (RRO) |
| Input Type | MUX-friendly inputs |
| Package | 8-SOIC (D) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +125C |
| Predecessor | OPA627 / OPA827 |
OPA828IDR Pin Configuration
| Pin 1 | TRIM — Offset trim / balance (connect per datasheet or leave floating for standard use) |
| Pin 2 | IN- — Inverting input |
| Pin 3 | IN+ — Non-inverting input |
| Pin 4 | V- — Negative supply |
| Pin 5 | NC/TRIM — No connect / trim (per SOIC-8 configuration) |
| Pin 6 | OUT — Rail-to-rail output |
| Pin 7 | V+ — Positive supply |
| Pin 8 | NC — No connect |
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
OPA828IDR is suitable for 6 applications: Photodiode Transimpedance Amplifier, High-Fidelity Audio Front End, Precision ADC / DAC Buffering, Industrial ±15V Analog Signal Chains, Active Filters and Instrumentation, Sensor Signal Conditioning with Multiplexed Inputs.
Photodiode Transimpedance Amplifier
The OPA828's 1 pA input bias current and 4 nV/√Hz noise make it ideal for photodiode TIA circuits where dark-current offset and Johnson-noise floor directly determine detection sensitivity. The 45 MHz bandwidth supports high transimpedance gain with megahertz-class signal bandwidth for optical receivers and spectroscopy. Placed directly after the photodiode with a feedback resistor and compensation capacitor, it converts picoampere photocurrents to usable voltages. Note that TI E2E reports show legacy OPA627 TIA designs may require feedback-network retuning when migrating to the OPA828 due to different phase-margin behavior.
Recommended
High-Fidelity Audio Front End
For hi-fi preamplifiers and DAC output stages, the OPA828 combines 4 nV/√Hz noise with 150 V/us slew rate, delivering low noise floor and clean transient handling for full-scale audio signals. The rail-to-rail output maximizes headroom on ±12 V to ±15 V rails, and its OPA627 heritage gives it strong audiophile acceptance. Community evaluations on diyAudio and YouTube comparisons confirm favorable results versus OPA627 and NE5532 in DAC I/V and buffer stages. Use a compensation capacitor in I/V configurations to maintain stability with DAC output capacitance.
Recommended
Precision ADC / DAC Buffering
Driving precision SAR and delta-sigma converters requires an amplifier with low offset (50 uV), low drift (0.45 uV/C), and enough bandwidth to settle within the converter's acquisition window. The OPA828's 45 MHz GBW settles quickly for 18-24 bit converter inputs, and its MUX-friendly inputs tolerate multiplexed sensor front ends without charge-injection damage. Placed between the signal source and the ADC input with an RC filter, it isolates converter switching charge from the source. The rail-to-rail output preserves full-scale dynamic range at low supply voltages.
Recommended
Industrial ±15V Analog Signal Chains
The OPA828's 36 V total supply range directly supports legacy ±15 V industrial rails without additional regulation, a key advantage over 5 V-tolerant modern amplifiers. In PLC analog input modules and process-control front ends, its 50 uV offset and 0.45 uV/C drift maintain accuracy across the -40C to +125C industrial temperature range, while 4 nV/√Hz noise preserves small-signal resolution from bridge and thermocouple sources. Combined with a precision reference and high-resolution ADC, it forms a complete industrial measurement channel compatible with existing backplane power architecture.
Recommended
Active Filters and Instrumentation
Test and measurement instrumentation demands active filter stages combining low noise with wide bandwidth. The OPA828's 45 MHz GBW supports multi-stage Sallen-Key and multiple-feedback filters at hundreds of kilohertz with minimal Q degradation from limited open-loop gain. Its 4 nV/√Hz noise keeps the filter's contribution below the source noise floor, and 1 pA bias current permits megohm-class resistor values without offset penalty, enabling low-frequency filters with practical capacitor sizes. The 150 V/us slew rate prevents slew-induced distortion on large-signal filter inputs in oscilloscope and signal-conditioning paths.
Recommended
Sensor Signal Conditioning with Multiplexed Inputs
The OPA828's MUX-friendly input stage is specifically designed for multiplexed signal chains: its inputs tolerate fast voltage transients from analog multiplexers without output phase reversal or latch-up, a common failure mode in JFET amplifiers. In multi-channel data acquisition, one OPA828 per channel or a shared gain stage after a multiplexer benefits from the 50 uV offset for accurate channel-to-channel matching. The 0.45 uV/C drift eliminates periodic recalibration in stable-temperature enclosures, and rail-to-rail output ensures the full ADC input range is usable even from 5 V single supplies after level shifting.
Recommended
Recommended Products Summary
Engineering reference data for OPA828IDR — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | OPA827 | OPA627 | AD8610ARZ | OPA2828 |
|---|---|---|---|---|---|
| Package | 8-SOIC (D) | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC (dual pinout) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Texas Instruments |
| Gain Bandwidth | 45 MHz | 22 MHz | 16 MHz | 25 MHz | 45 MHz |
| Slew Rate | 150 V/us | 40 V/us | 55 V/us | 50 V/us | 150 V/us |
| Voltage Noise | 4 nV/√Hz | 3.8 nV/√Hz | 4.5 nV/√Hz | 6 nV/√Hz | 4 nV/√Hz |
| Input Bias Current | 1 pA | 1.5 pA | 1 pA | 1 pA | 1 pA |
| Output Stage | Rail-to-Rail Output | Non-RRO | Non-RRO | Rail-to-Rail Output | Rail-to-Rail Output |
| Channels | 1 | 1 | 1 | 1 | 2 |
Key Differentiators
- Widest bandwidth in the OPA627/827 precision JFET lineage (vs OPA627)
- Rail-to-rail output extends dynamic range (vs OPA827)
- 36 V total supply tolerance (vs AD8610ARZ)
Design Notes
Place 0.1 uF ceramic decoupling capacitors within 3 mm of the V+ and V- pins, plus a 2.2 uF to 10 uF bulk capacitor per supply rail. The SOIC-8 package with 45 MHz bandwidth is sensitive to parasitic capacitance at the inverting node; keep feedback resistor traces short and guard the high-impedance input trace with a driven guard ring to preserve the 1 pA bias-current advantage in TIA circuits.
Although TI markets the OPA828 as an OPA627 replacement, TI E2E forum case 1218326 documents a legacy photodiode TIA that failed after direct substitution. Differences in phase margin and output-stage topology mean feedback compensation capacitors and load conditions should be re-verified. Simulate the TIA loop stability with the OPA828 SPICE model (available free from TI) before committing the PCB.
The rail-to-rail output stage exhibits higher output impedance near the rails; keep closed-loop gain and load capacitance within datasheet stability curves when driving long cables or ADC input capacitors. A series output resistor of 25-50 ohm isolates capacitive loads. For MUX applications, take advantage of the MUX-friendly inputs but still add a small series resistor at the input to limit transient current during channel switching.
Compliance Information
RoHS compliant per TI product page; standard commercial-grade (not automotive Q1). REACH and halogen-free status to be confirmed on TI quality portal.
