Texas Instruments VCA810IDR

Overview

VCA810IDR from Texas Instruments is a DC-coupled, wideband, voltage-controlled gain amplifier with differential input and single-ended output. It delivers ±40 dB gain adjust range (–40 dB to +40 dB), 35 MHz small-signal bandwidth, 2.4 nV/√Hz input voltage noise, ±60 mA output current, and operates from ±5-V supplies. It serves as a precision analog gain control element in optical receiver time gain control and AGC receivers with RSSI functionality.

For engineers reviewing the VCA810IDR datasheet, VCA810IDR pinout, VCA810IDR application, or VCA810IDR equivalent, key selection criteria include its constant 35 MHz bandwidth across gain settings, ±0.3 dB gain linearity, 25 MHz gain control bandwidth, low 40 mV max output DC error, and SOIC-8 package compatibility with ±5-V dual-supply systems.

Technical Context

The VCA810IDR implements a transconductance-based variable-gain architecture where gain is linearly controlled in dB/V via a high-impedance voltage input (VC, Pin 3). Its differential input stage provides >80 dB common-mode rejection and supports both single-ended and differential signal injection while maintaining constant bandwidth and group delay over the full ±40 dB gain range.

Gain control is achieved through an internal translinear cell with 25 mV/dB slope (–40 dB/V), enabling accurate received signal strength indication (RSSI) with ±1.5 dB accuracy. The output stage drives 50-Ω doubly-terminated lines or ADC inputs within ±1.7 V output swing at ±60 mA current capability.

Key Specifications

Pinout & Package

Package: SOIC-8 (4.90 mm × 3.91 mm body size), surface-mount, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage-controlled amplifier applications.

Compared with VCA2612 and VCA820IDR, the VCA810IDR uniquely balances 40 dB gain range, 35 MHz bandwidth, and 2.4 nV/√Hz noise in an SOIC-8 package with proven ±5-V dual-rail compatibility-making it optimal for optical TGC and sonar front-ends requiring calibrated RSSI.

Availability

VCA810IDR is available at Aetrix Electronics and suitable for optical receiver time gain control, sonar systems, and AGC receivers requiring stable component supply, long-term manufacturability, and TI-qualified performance across –40°C to +85°C.

Supply support for VCA810IDR 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, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The VCA810IDR belongs to TI's high-speed variable-gain amplifier product line, engineered specifically for precision analog signal conditioning in optical, ultrasonic, and RF receiver front-ends demanding wide dynamic range and calibrated gain control.

FAQ

What is the gain control voltage range for the VCA810IDR?

The VCA810IDR accepts a gain control voltage (VC) from 0 V to –2 V, corresponding to a gain range of –40 dB to +40 dB. At VC = 0 V, gain is –40 dB; at VC = –2 V, gain is +40 dB. Input voltages above +0.15 V disable the output. This 25 mV/dB slope enables direct use of VC as an RSSI output with ±1.5 dB accuracy across temperature.

Does the VCA810IDR require dual supplies, and what are the operating limits?

Yes, the VCA810IDR requires symmetrical dual supplies: ±4 V to ±5.5 V. It is specified for ±5 V operation with typical quiescent current of 24.8 mA total (12.5 mA on +VS, 12.3 mA on –VS at 40 dB gain). Operation outside ±6.5 V absolute maximum ratings risks permanent damage. The device draws no current from the VC pin, simplifying control interface design.

How does the VCA810IDR maintain constant bandwidth across its gain range?

The VCA810IDR uses a transconductance-based gain control architecture that decouples gain adjustment from signal path capacitance. Its small-signal bandwidth remains constant at 35 MHz (typical) from –40 dB to +40 dB gain because the gain-setting mechanism modulates transconductance without altering dominant-pole frequency. This eliminates the need for gain-dependent compensation in TGC or sonar systems.

What is the maximum output swing and load drive capability of the VCA810IDR?

The VCA810IDR delivers ±1.7 V output swing into a 100 Ω load at ±5 V supplies and provides ±60 mA output current. It can directly drive doubly-terminated 50 Ω transmission lines or ADC inputs without external buffers. Output impedance is 0.2 Ω below 100 kHz, ensuring minimal signal loss in impedance-matched configurations used in RF and ultrasound applications.

Can the VCA810IDR be used with single-ended input signals?

Yes, the VCA810IDR supports single-ended input operation by applying the signal to +In (Pin 1) while grounding –In (Pin 8), or vice versa. The differential input stage maintains high common-mode rejection (>80 dB) even in single-ended mode. DC bias paths must be provided-e.g., 50 Ω termination to ground-to ensure proper input transistor biasing and avoid saturation.