Texas Instruments OPA1S2385IDRCR

Overview

OPA1S2385IDRCR from Texas Instruments is a 250-MHz CMOS transimpedance amplifier (TIA) with integrated SPST switch and dual-channel buffer, designed for photodiode current-to-voltage conversion and fast sample-and-hold in optical networking. It delivers rail-to-rail I/O swing, 150 V/μs slew rate, 3 pA input bias current, and operates from +2.7 V to +5.5 V single supply - enabling burst-mode RSSI detection in GPON/EPON receivers.

For engineers reviewing the OPA1S2385IDRCR datasheet, OPA1S2385IDRCR pinout, OPA1S2385IDRCR application, or OPA1S2385IDRCR equivalent, this page provides verified functional specifications, validated pin assignments, confirmed transimpedance and sample-and-hold use cases, and two documented alternative parts with explicit technical and application differences.

Technical Context

The OPA1S2385IDRCR integrates a high-speed FET-input op amp (Channel A) configured as transimpedance amplifier, an internal CMOS SPST switch (IN_S to +IN_B path), and a second rail-to-rail buffer (Channel B). Its active-low SC control pin directly closes the switch at logic low, distinguishing it from the OPA1S2384.

It supports flexible signal conditioning: Channel A converts photodiode current with 250-MHz small-signal bandwidth and 6 nV/√Hz voltage noise; the switch enables precise sampling with 1 pC charge injection and 4 Ω on-resistance; Channel B buffers the held voltage with 11 ns rise/fall time and 30 ns settling to 0.1%.

Key Specifications

Pinout & Package

OPA1S2385IDRCR uses a 3-mm × 3-mm SON-10 (DRC) package with wettable flanks, optimized for automated optical module assembly and thermal performance (θJA = 46.2°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transimpedance amplifier with integrated switch applications.

Compared with OPA1S2385IDRCR, OPA1S2384IDRCR offers identical analog performance but inverted switch control logic, while LMH6629MA/NOPB trades integration for lower voltage noise - making OPA1S2385IDRCR optimal for compact, timing-critical optical burst sampling where switch timing predictability and layout simplicity are essential.

Availability

OPA1S2385IDRCR is available at Aetrix Electronics and suitable for optical networking, photodiode monitoring, and fast sample-and-hold applications requiring stable component supply, long-term lifecycle support, and traceable sourcing for industrial and telecom deployments.

Supply support for OPA1S2385IDRCR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in high-speed amplifiers and optical interface solutions.

The OPA1S2385IDRCR belongs to TI's high-bandwidth transimpedance amplifier product line, engineered specifically for low-voltage, single-supply optical receiver front-ends in EPON, GPON, and burst-mode communication systems.

FAQ

What is the function of the SC pin on the OPA1S2385IDRCR?

The SC (Switch Control) pin on the OPA1S2385IDRCR is an active-low digital input that controls the internal SPST CMOS switch. When SC is logic low, the switch closes, connecting IN_S to +IN_B; when SC is logic high, the switch opens, isolating the two nodes. This behavior distinguishes OPA1S2385IDRCR from the OPA1S2384IDRCR, which uses active-high control. The pin accepts 0 V to V+ logic levels and draws ≤0.01 µA leakage current across temperature.

How does the OPA1S2385IDRCR support photodiode transimpedance applications?

The OPA1S2385IDRCR supports photodiode transimpedance applications through Channel A's FET-input architecture, delivering 3 pA input bias current, 6 nV/√Hz input voltage noise at 1 MHz, and 250-MHz small-signal bandwidth - all critical for preserving signal integrity in high-speed optical receivers. Its rail-to-rail input allows direct connection to photodiode cathodes, while the 10¹³ Ω || 2 pF input impedance avoids loading photodiode junction capacitance and maintains loop stability in TIA configurations.

Can the OPA1S2385IDRCR be used in a single-supply 3.3-V system?

Yes, the OPA1S2385IDRCR is fully specified for single-supply operation from +2.7 V to +5.5 V, including 3.3 V. At 3.3 V, it delivers 110 V/μs slew rate, 90 MHz gain bandwidth (G = 10), and rail-to-rail input/output swing with 100 mV headroom to each rail. Quiescent current remains 9.2 mA, and key parameters like input bias current (3 pA) and charge injection (1 pC) are maintained - making it ideal for low-voltage optical modules compliant with GPON MSA requirements.

What is the maximum capacitive load the OPA1S2385IDRCR can drive stably?

The OPA1S2385IDRCR is characterized to drive ≥100 pF capacitive loads in unity-gain configuration without oscillation, as verified in Figure 11 of the SBOS645A datasheet. With a 10-Ω series resistor (RS) at the output, stability extends to >1 nF. For loads >100 pF, TI recommends using RS = 10–20 Ω to suppress ringing while accepting a minor DC gain error (e.g., 0.2% with RL = 10 kΩ and RS = 20 Ω). Output impedance remains ≤0.05 Ω up to 1 MHz, ensuring robust drive capability.

How does the OPA1S2385IDRCR achieve fast settling in sample-and-hold mode?

The OPA1S2385IDRCR achieves fast settling in sample-and-hold mode via three integrated features: (1) Channel A's 250-MHz bandwidth and 150 V/μs slew rate enable rapid tracking; (2) the internal switch's 20 ns turn-on and 15 ns turn-off times minimize aperture uncertainty; and (3) Channel B's 11 ns rise/fall time and 30 ns settling to 0.1% ensure the held voltage stabilizes quickly after sampling. These characteristics collectively support effective sampling rates exceeding 10 MS/s in optical burst detection systems.