Texas Instruments VCA810ID

Overview

VCA810ID from Texas Instruments is a DC-coupled, wideband, voltage-controlled gain amplifier with differential input and single-ended output, delivering ±40 dB gain adjust range linear in dB/V (–40 dB at 0 V VC, +40 dB at –2 V VC), 35 MHz small-signal bandwidth, 2.4 nV/√Hz input noise, and ±60 mA output drive - deployed in optical receiver time gain control and AGC receivers with RSSI functionality.

For engineers reviewing the VCA810ID datasheet, VCA810ID pinout, VCA810ID application, or VCA810ID equivalent, this page provides verified technical context on its constant-bandwidth operation across gain settings, high dB/V linearity (±0.3 dB), gain control bandwidth (25 MHz), low output DC error (< ±40 mV), and differential-input common-mode rejection for precision analog signal conditioning.

Technical Context

The VCA810ID implements a transconductance-based variable-gain architecture where the gain-control voltage (VC, Pin 3) modulates internal current steering to achieve precise logarithmic gain scaling. Its differential input stage operates with high-impedance inputs (≥10 MΩ||<2 pF) and supports both single-ended and differential signal sources while maintaining >80 dB common-mode rejection at 0 dB gain.

Gain control is implemented via a dedicated high-bandwidth (25 MHz) path independent of signal path dynamics, enabling fast AGC loop response without affecting group delay flatness (≤3.5 ns variation over 5 MHz). Output stage delivers ±1.7 V swing into 100 Ω and maintains constant slew rate (300–350 V/μs) and settling time (≤41 ns to 0.01%) across the full ±40 dB gain range.

Key Specifications

Pinout & Package

Package: SOIC-8 (D package), body size 4.90 mm × 3.91 mm, 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 VCA820ID and VCA2612IPW, the VCA810ID uniquely balances 35 MHz bandwidth, ±40 dB range, and 2.4 nV/√Hz noise in a single-channel SOIC-8 footprint - making it optimal for single-path high-fidelity TGC, sonar, and RSSI-critical AGC where speed, accuracy, and layout simplicity are prioritized.

Availability

VCA810ID is available at Aetrix Electronics and suitable for optical time gain control, sonar pulse conditioning, and AGC receiver designs requiring stable component supply, long-term industrial temperature support (–40°C to +85°C), and guaranteed traceable sourcing.

Supply support for VCA810ID 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, embedded processing, and connectivity technologies for industrial, automotive, and communications markets.

The VCA810ID belongs to TI's high-speed variable-gain amplifier product line, engineered for precision analog signal conditioning in time-critical applications such as optical receivers, sonar, and automatic gain control systems demanding wide bandwidth, low noise, and accurate dB-linear gain control.

FAQ

What is the gain control voltage range for the VCA810ID?

The VCA810ID accepts a single-ended gain control voltage (VC) from 0 V to –2 V. At VC = 0 V, gain is –40 dB; at VC = –2 V, gain is +40 dB. The device achieves –40 dB/V gain slope with ±0.3 dB linearity (high-grade) over the central –1.8 V to –0.2 V range. Voltages above +0.15 V disable the output, providing a functional mute capability.

Does the VCA810ID support differential input signals?

Yes, the VCA810ID features true differential inputs (+In and –In) with high input impedance (>10 MΩ) and >80 dB common-mode rejection ratio at 0 dB gain. It accepts both differential and single-ended inputs, but external DC bias paths must be provided for input transistor base currents - typically via matched resistors to ground or through the signal source.

What is the maximum output voltage swing of the VCA810ID?

The VCA810ID delivers ±1.7 V output swing into a 100 Ω load at ±5 V supplies, and ±1.3 V under worst-case temperature and supply conditions (–40°C to +85°C, ±4 V supplies). Output remains linear up to 3 VPP differential input at minimum gain, and supports ±60 mA continuous output current for driving heavy loads including doubly-terminated 50-Ω lines.

How does the VCA810ID maintain constant bandwidth across gain settings?

The VCA810ID uses a transconductance-based architecture where gain modulation occurs via current steering without altering the signal path's dominant pole. This preserves 35 MHz small-signal bandwidth and 300–350 V/μs slew rate across the full ±40 dB gain range - confirmed in datasheet Figures 1 and 21 - enabling consistent pulse fidelity in time-domain applications like sonar and optical TGC.

Is the VCA810ID pin-compatible with the VCA610?

Yes, the VCA810ID is an improved replacement for the VCA610 with identical SOIC-8 pinout and supply interface. Key upgrades include wider gain range (±40 dB vs ±30 dB), higher bandwidth (35 MHz vs 25 MHz), lower input noise (2.4 nV/√Hz vs 3.5 nV/√Hz), and enhanced gain linearity (±0.3 dB vs ±1.0 dB). No PCB changes are required for drop-in replacement in legacy VCA610 designs.