Texas Instruments VCA824ID

Overview

VCA824ID from Texas Instruments is a DC-coupled, ultra-wideband, linear-in-V/V variable gain amplifier (VGA) with differential input and single-ended output. It delivers 710-MHz small-signal bandwidth at G = 2 V/V, 0.1-dB gain flatness to 135 MHz, 2500-V/µs slew rate, >40-dB gain adjust range, and ±90 mA output current-enabling high-fidelity pulse amplitude compensation in video equalization and RF signal chains.

For engineers reviewing the VCA824ID datasheet, VCA824ID pinout, VCA824ID application, or VCA824ID equivalent, key selection criteria include gain linearity over ±1 V control voltage, 420-MHz bandwidth at 10 V/V max gain, thermal performance in SOIC-14 package, and compatibility with ±5-V supplies for high-speed analog front-end designs.

Technical Context

The VCA824ID integrates two input buffers and a current-feedback output amplifier with a multiplier core, eliminating need for external buffering. Its gain is set externally via RG and RF resistors, supporting nominal maximum gains from 2 V/V to 40 V/V.

Gain control operates linearly in V/V across VG = –1 V to +1 V, delivering precise attenuation (e.g., 10 V/V → 0.1 V/V) with ±0.3-dB accuracy at 20-dB setting and 25°C. Input common-mode range spans –2.1 V to +1.6 V with 65-dB CMRR at 85°C.

Key Specifications

Pinout & Package

The VCA824ID is available in SOIC-14 (8.65 mm × 3.91 mm) and VSSOP-10 (3.00 mm × 3.00 mm) packages. This entry refers specifically to the SOIC-14 variant (D package), pin-compatible with industry-standard 14-pin SOIC footprints and reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VCA824ID, VCA822ID trades 0.1-dB flatness (135 MHz vs 150 MHz) and VREF flexibility for lower cost, while VCA821ID offers identical bandwidth but sacrifices gain control range and noise performance-making VCA824ID optimal for DC-coupled, high-linearity, wide-flatness applications.

Availability

VCA824ID is available at Aetrix Electronics and suitable for differential line receivers, video equalizers, and pulse amplitude compensation systems requiring stable component supply, long-term manufacturability, and guaranteed traceability.

Supply support for VCA824ID 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 signal chain solutions.

The VCA824ID belongs to TI's ultra-wideband variable gain amplifier product line, designed specifically for high-fidelity analog signal conditioning in video, communications, and test equipment where DC coupling, gain linearity, and bandwidth flatness are critical.

FAQ

What is the maximum small-signal bandwidth of the VCA824ID?

The VCA824ID achieves 710-MHz small-signal bandwidth when configured for a maximum gain of 2 V/V at ±5-V supplies. At higher gains-such as 10 V/V-the bandwidth reduces to 420 MHz, and at 40 V/V it is 170 MHz. These values are measured under specified load and signal conditions per the official SBOS394E datasheet, and represent usable analog bandwidth before –3-dB roll-off.

Does the VCA824ID support DC-coupled operation?

Yes, the VCA824ID supports true DC-coupled operation across its entire gain range. Its input stage accepts DC and low-frequency signals down to 0 Hz, and the gain control voltage VG operates linearly from –1 V to +1 V. This enables precise amplitude scaling of baseband waveforms-including video sync pulses and sensor outputs-without AC coupling capacitors or associated drift issues.

What is the purpose of the VREF pin on the VCA824ID?

The VREF pin on the VCA824ID serves as the noninverting input of the internal output buffer, establishing the DC reference level for the single-ended VOUT. It allows users to set the output common-mode voltage independently-critical for interfacing with ADCs, downstream amplifiers, or level-sensitive circuits. Leaving VREF unconnected defaults to internal bias, but external control ensures optimal DC alignment in precision systems.

Can the VCA824ID drive a 100-Ω load effectively?

Yes, the VCA824ID delivers ±90 mA output current and specifies 3.5 VPP output swing into a 100-Ω load at 25°C. This capability supports direct driving of coaxial cables, ADC inputs, or other low-impedance destinations without external buffers. Thermal derating applies above 25°C, with output swing decreasing to 3.2 VPP at 85°C ambient-verified in the SBOS394E Electrical Characteristics table.

How does gain accuracy vary across temperature for the VCA824ID?

At a 20-dB maximum gain setting, the VCA824ID maintains ±0.4-dB gain error at 25°C, degrading to ±0.6-dB over the full –40°C to +85°C operating range. Gain deviation over the 0–1 V VG range remains within ±0.37 dB at 85°C. These values reflect measured performance under ±5-V supplies and are documented in Section 7.5 of the SBOS394E datasheet, ensuring predictable behavior in industrial and automotive environments.