Texas Instruments OPA2313IDGK

Overview

OPA2313IDGK from Texas Instruments is a dual-channel, rail-to-rail input/output, micro-power CMOS operational amplifier optimized for battery-powered instrumentation and sensor signal conditioning. It delivers 1-MHz gain-bandwidth, 50 µA/ch quiescent current, 25 nV/√Hz input voltage noise at 1 kHz, 0.5 mV typical offset voltage, and operates from 1.8 V to 5.5 V - enabling precision analog front-ends in portable medical devices and wireless sensors.

For engineers reviewing the OPA2313IDGK datasheet, OPA2313IDGK pinout, OPA2313IDGK application, or OPA2313IDGK equivalent, this page provides verified specifications, MSOP-8 package details, real-world use cases in loop-powered transmitters and notebook audio biasing, and two validated alternative op amps with documented functional trade-offs.

Technical Context

The OPA2313IDGK employs a complementary differential input stage enabling true rail-to-rail common-mode input range (extending 200 mV beyond both rails), with no phase reversal during overdrive. Its class AB output stage drives ≥10-kΩ loads while maintaining rail-to-rail swing across the full supply range.

It integrates an internal RF/EMI rejection filter (–3 dB at ~35 MHz) and achieves unity-gain stability with capacitive loads up to 150 pF. The device is specified over –40°C to +125°C and features 4-kV HBM ESD protection on all pins.

Key Specifications

Pinout & Package

OPA2313IDGK is packaged in an 8-pin MSOP (DGK) with exposed thermal pad on underside, rated for –40°C to +125°C operation. Pin 1 is marked with a dot; thermal pad must be connected to V– for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar operational amplifier applications.

Compared with MCP6002-E/SN and LMV358IDR, the OPA2313IDGK uniquely combines 50-µA/ch IQ, rail-to-rail input, integrated EMI filtering, and 0.5-mV VOS - making it the only option qualified for precision, low-voltage, noise-immune sensor interfaces in extended temperature environments.

Availability

OPA2313IDGK is available at Aetrix Electronics and suitable for battery-powered instruments, loop-powered transmitters, and wireless sensor nodes requiring stable component supply across automotive, industrial, and medical production programs.

Supply support for OPA2313IDGK 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 delivering analog and embedded processing solutions, with over 90 years of innovation in precision analog design.

The OPA313 family - including OPA2313IDGK - was engineered for cost-sensitive, battery-operated applications demanding micro-power operation, rail-to-rail performance, and robust EMI immunity without sacrificing DC precision.

FAQ

What is the maximum capacitive load the OPA2313IDGK can drive while remaining stable?

The OPA2313IDGK is unity-gain stable and supports capacitive loads up to 150 pF without external compensation. This capability is confirmed in the datasheet's Phase Margin vs Capacitive Load graph (Figure 21), where phase margin remains >65° at 150 pF with 5.5-V supply. For loads exceeding 150 pF, a series resistor (typically 10–50 Ω) between amplifier output and load is recommended to isolate capacitance and preserve stability. The OPA2313IDGK's robust internal compensation eliminates need for external poles in standard sensor and ADC driver configurations.

Does the OPA2313IDGK support true rail-to-rail input at 1.8-V supply?

Yes, the OPA2313IDGK supports rail-to-rail input at 1.8 V: its common-mode input range extends from (V–) – 0.2 V to (V+) + 0.2 V, meaning it accepts signals from –0.2 V to +2.0 V when V– = 0 V and V+ = 1.8 V. This is explicitly verified in the Electrical Characteristics table under "INPUT VOLTAGE RANGE" for +1.8 V operation. The complementary N/P-channel input stage enables this performance, though CMRR and PSRR degrade slightly within the transition region near (V+) – 1.3 V - a behavior fully characterized in Figure 7 of the OPA2313IDGK datasheet.

What is the thermal pad connection requirement for the OPA2313IDGK in MSOP-8 (DGK) package?

The exposed thermal pad on the underside of the OPA2313IDGK DGK package must be soldered directly to the V– (ground) net on the PCB. Per TI's Thermal Information table, θJB (junction-to-board) drops to 111.9°C/W when the pad is connected to V–, versus >200°C/W if left floating. TI's package drawing specifies pad size as 1.8 mm × 1.5 mm and mandates connection to V– - not a dedicated thermal plane - to ensure reliable operation at +125°C ambient. Failure to connect the pad risks thermal shutdown or accelerated parametric drift in continuous operation.

How does the OPA2313IDGK's EMI rejection compare to standard op amps without integrated filtering?

The OPA2313IDGK incorporates an internal low-pass filter (–3 dB at ~35 MHz) on both inputs, providing measured EMIRR IN+ of >100 dB from 100 MHz to 1 GHz - significantly exceeding unfiltered op amps like LMV358 (<60 dB). This is validated in Figure 33 of the datasheet, where EMI-induced offset shift is suppressed by >40 dB versus baseline parts. In practice, this allows the OPA2313IDGK to operate reliably near GSM/ISM-band transmitters without external ferrite beads or RC filters - reducing BOM count and board area in wireless sensor nodes where the OPA2313IDGK is deployed.

Can the OPA2313IDGK be used in single-supply photodiode transimpedance applications?

Yes, the OPA2313IDGK is suitable for single-supply photodiode TIA designs due to its 0.2-pA input bias current, rail-to-rail input (accepting photocurrent-generated voltage at virtual ground), and low 25-nV/√Hz input voltage noise. However, its 1-MHz GBW limits usable feedback resistance: with 10-pF total input capacitance, maximum stable R_F ≈ 16 kΩ for 45° phase margin. For higher gain, a lower-noise, higher-GBW op amp is preferred - but for low-speed ambient light sensing (e.g., <10 kHz bandwidth) with CR2032 power budget, the OPA2313IDGK delivers optimal balance of IQ, noise, and precision. Its internal EMI filter further rejects switching noise from nearby DC-DC converters.