OPT211 - Monolithic Photodiode + Transimpedance Amp | Burr-Brown (TI)
Référence : OPT211 ✗ Fin de vie| Qté | Prix unitaire | Total |
|---|---|---|
| 1 | $18.5 | $18,50 |
| 10 | $16.25 | $162,50 |
| 100 | $13.95 | $1 395,00 |
| 500 | $12.1 | $6 050,00 |
| 1 000 | $10.5 | $10 500,00 |
OPT211 Présentation
A monolithic photodiode plus transimpedance amplifier (TIA) combines a light-sensing element and a current-to-voltage conversion stage on one die. Photodiodes generate a small photocurrent proportional to incident light; a transimpedance amplifier converts that current into a usable voltage with high gain and low noise, which is critical in optical sensing front-ends. This category sits within optical sensors and front-end analog ICs, used wherever light must be measured precisely, from scientific instruments to industrial position sensing.
Key features include very high transimpedance gain (up to 10^8 V/A typical), bandwidth up to several hundred kHz at moderate gain, low dark current due to on-chip FET input, and a wide dynamic range achievable through trade-offs between responsivity, bandwidth, and SNR. The uncommitted input and feedback pins allow designers to choose feedback resistor values for optimized noise-bandwidth trade-offs and to add filtering stages for specific applications.
The OPT211's architecture pairs a diffused silicon photodiode with a precision FET-input op-amp transimpedance topology. Because the photodiode and amplifier share the same die, parasitic capacitance and leakage are minimized compared to discrete implementations, improving noise performance at high gain. The exposed feedback node allows external compensation, gain setting, or T-network feedback for very high effective transimpedance.
Typical applications include precision photometry, optical position encoders, laser power measurement, smoke detectors, barcode scanners, spectrophotometers, and medical analytical instruments. It is well suited for low-light-level detection where the integrated front-end reduces PCB complexity and stray noise pickup.
When designing with the OPT211, pay close attention to PCB layout: keep feedback components close to the feedback pin, use a guard ring around the input traces, and provide proper supply bypassing (0.1 uF ceramic in parallel with a larger tantalum or ceramic). Note that the OPT211 is a legacy Burr-Brown part now owned by Texas Instruments; long-term availability should be verified before new designs.
Alternatives de remplacement direct pour OPT211 — même boîtier, compatible broche à broche. Les références à boîtier différent nécessitant une retouche du PCB sont exclues.
Outil de comparaison rapide — sélectionnez des références alternatives pour une comparaison côte à côte :
OPT101
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
OPT202
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
OPT3001
✅ Remplacement direct ⚠️ Spécifications non vérifiées📋 Alternative de référence (hors catalogue)
OPT211 Valeurs maximales et caractéristiques électriques
| Product Type | Monolithic Photodiode with Transimpedance Amplifier |
| Manufacturer | Burr-Brown (Texas Instruments) |
| Supply Voltage Range | +/-2.25 V to +/-18 V (dual supply) |
| Transimpedance Gain (max) | Up to 1 x 10^8 V/A (with external feedback network) |
| Bandwidth | Up to several hundred kHz at moderate gain (gain-bandwidth dependent) |
| Boîtier | 8-pin PDIP (suffix P) |
| Type de montage | Through-Hole |
| Niveau MSL | Not applicable (through-hole) |
Configuration des broches de OPT211
| Broche 1 | NC — No Connection (per datasheet) |
| Broche 2 | -VS — Negative supply voltage |
| Broche 3 | +IN — Non-inverting amplifier input (photodiode anode) |
| Broche 4 | -IN — Inverting amplifier input (photodiode cathode / TIA summing junction) |
| Broche 5 | FB — Feedback node (external feedback resistor to -IN) |
| Broche 6 | OUT — Amplifier output |
| Broche 7 | +VS — Positive supply voltage |
| Broche 8 | NC — No Connection (per datasheet) |
Applications typiques
OPT211 convient pour 7 applications: Precision Photometry and Light Measurement, Optical Position Encoders, Smoke and Particulate Detectors, Laser Power Measurement, Barcode Scanners and Optical Readers, Medical Analytical Instruments, Spectrophotometers and Colorimeters.
Precision Photometry and Light Measurement
The OPT211's monolithic photodiode plus on-chip FET-input transimpedance amplifier is ideal for precision photometry where stray capacitance must be minimized. With transimpedance gain reaching 1x10^8 V/A and bandwidth extending to hundreds of kHz, the part converts very small photocurrents into measurable voltages with low noise. Designers use it in laboratory photometers, lux meters, and reference light sources where the integrated front-end delivers superior SNR compared to discrete photodiode + op-amp implementations.
Recommandé
Optical Position Encoders
In optical encoders the OPT211 detects modulated light through a slotted disc, producing a current proportional to the duty cycle of the slot pattern. Its wide bandwidth at high transimpedance gain allows it to resolve high-count-per-revolution encoders without slew-rate limiting. The integrated front-end eliminates long input traces that would otherwise pick up EMI in industrial environments, making the OPT211 well-suited to factory-floor motor feedback systems.
Recommandé
Smoke and Particulate Detectors
Smoke detectors rely on detecting scattered light from smoke particles inside a sensing chamber. The OPT211's integrated photodiode + TIA detects the small scattered-light photocurrent with high sensitivity, while its on-chip FET input provides the low bias current needed to resolve picoampere-level signals. The 8-pin PDIP package allows easy integration through-hole mounting in legacy smoke detector designs.
Recommandé
Laser Power Measurement
Laser power meters require accurate measurement of continuous or pulsed laser intensity. The OPT211's wide bandwidth allows it to track modulated laser sources, while its high transimpedance gain captures even small photocurrents from low-power laser diodes. Designers place the OPT211 behind a calibrated photodiode bias network and use the on-chip amplifier to deliver a voltage proportional to incident optical power.
Recommandé
Barcode Scanners and Optical Readers
Barcode scanners require fast, sensitive detection of modulated light reflected from printed barcodes. The OPT211's bandwidth at moderate transimpedance gain suits the kilohertz modulation rates typical of moving-beam laser scanners, while its low noise floor preserves contrast between black bars and white spaces. The integrated photodiode simplifies the optical bench layout in fixed-mount industrial scanners.
Recommandé
Medical Analytical Instruments
Medical analyzers such as spectrophotometers, hematology counters, and chemiluminescence readers rely on precise photodetection across a wide dynamic range. The OPT211's high transimpedance gain combined with the uncommitted feedback network allows designers to optimize the noise-bandwidth trade-off for specific assay chemistries. The integrated front-end reduces PCB real estate in compact benchtop instruments.
Recommandé
Spectrophotometers and Colorimeters
In spectrophotometers, the OPT211 detects transmitted or reflected light across the visible and near-IR spectrum. Designers pair it with bandpass filters and use the on-chip TIA to convert narrow-band photocurrents into measurable voltages. The uncommitted feedback node allows precision gain tuning for specific absorbance ranges, supporting both high-absorbance (low transmission) and low-absorbance (high transmission) measurement regimes.
Recommandé
Récapitulatif des produits recommandés
Données de référence d'ingénierie pour OPT211 — comparaison, recommandations de conception et informations de conformité.
Guide de sélection
Comparaison avec les alternatives
| Paramètre | Ce produit | OPT101 | OPT202 | OPT3001 |
|---|---|---|---|---|
| Package | 8-pin PDIP | 8-pin PDIP - same | 8-pin PDIP - same | 6-pin USON - different |
| Brand | Texas Instruments (Burr-Brown) | Texas Instruments | Texas Instruments (Burr-Brown) | Texas Instruments |
| Architecture | Analog photodiode + TIA | Analog photodiode + on-chip amplifier | Analog photodiode + TIA | Digital I2C ambient light sensor |
| Output Interface | Analog voltage | Analog voltage | Analog voltage | I2C digital |
| Transimpedance Gain (max) | Up to 1 x 10^8 V/A | Internal 1 MOhm, external up to 1x10^8 | Up to 1x10^7 V/A | N/A (digital) |
| Lifecycle Status | NRND / Legacy | Active | NRND / Legacy | Active |
| Mounting Type | Through-Hole | Through-Hole (also SOT-23 option) | Through-Hole | Surface Mount |
Principaux différenciateurs
- Highest transimpedance gain with wide bandwidth in legacy monolithic photodiode family (vs OPT101)
- Analog real-time output suitable for fast modulation (vs OPT3001)
- Uncommitted feedback node for application-specific tuning (vs OPT101)
Notes de conception
Keep the external feedback resistor and compensation capacitor as close to the OPT211 feedback pin as possible - lead lengths greater than 5 mm introduce parasitic inductance that creates ringing at high transimpedance gain. Use a ground guard ring around the input traces on the PCB to prevent leakage currents from contaminating the picoampere-level photodiode signal. Avoid running digital signals parallel to the high-impedance input traces; route them on the opposite PCB layer with a continuous ground plane in between.
Bypass each supply pin with a 0.1 uF ceramic capacitor in parallel with a 10 uF tantalum or aluminum electrolytic capacitor, placed within 5 mm of the supply pins. The OPT211's high-gain transimpedance stage is sensitive to supply noise, which couples directly into the output. For lowest noise, use linear regulators (rather than switching regulators) on the +/-VS rails feeding the OPT211. Add ferrite beads in series with the supply traces if switching noise is unavoidable.
Do not exceed the maximum supply voltage of +/-18 V or the absolute maximum photodiode reverse bias specified in the datasheet - over-voltage destroys the on-chip photodiode junction. The uncommitted feedback node requires an external resistor; operating the OPT211 without a feedback resistor results in open-loop instability and possible oscillation. Verify feedback resistor power dissipation when operating at high photocurrents (1 mA or higher): P = I^2 x R, and a 1 MOhm resistor at 1 mA dissipates 1 W.
At maximum transimpedance gain (1x10^8 V/A), the OPT211 bandwidth shrinks to a few kHz. This gain-bandwidth trade-off is fundamental and cannot be bypassed - to maximize SNR at high gain, add a low-pass filter after the transimpedance stage (rather than reducing feedback resistance). For pulsed-light applications, choose a feedback resistor that yields a -3 dB bandwidth at least 5x the pulse repetition rate to avoid pulse-edge distortion.
Estimated: at +/-15 V supply with the photodiode exposed to typical indoor ambient light (~500 lux), the OPT211 dissipates approximately 100 mW. The 8-pin PDIP package has a theta_JA of approximately 100 C/W, resulting in a 10 C junction temperature rise above ambient - well within the operating range. At maximum photocurrent (1 mA into 1 MOhm feedback) the dissipation can reach 1 W; in that case, consider reducing supply voltage to +/-5 V or adding a clip-on heatsink.
Informations de conformité
Compliance data not confirmed in the verified sources. OPT211 is a legacy Burr-Brown design now owned by Texas Instruments; consult TI product environmental compliance documents or contact TI directly for current RoHS, REACH, and lead-free status. Through-hole PDIP packages from this era are often non-RoHS; a RoHS-compliant variant may not exist.
