Texas Instruments VCA820IDR

Overview

VCA820IDR from Texas Instruments is a wideband, linear-in-dB voltage-controlled variable gain amplifier (VGA) with differential input and single-ended output. It delivers 150-MHz small-signal bandwidth, 137-MHz 5-V_PP large-signal bandwidth, 0.1-dB gain flatness to 28 MHz, 1700-V/μs slew rate, and >40-dB gain adjust range. It is used in AGC receivers with RSSI, pulse amplitude compensation, and differential line receivers.

For engineers reviewing the VCA820IDR datasheet, VCA820IDR pinout, VCA820IDR application, or VCA820IDR equivalent, key selection criteria include gain control linearity (±0.4 dB at 20 dB max gain), high output current (±160 mA), CMRR (60–80 dB), input-referred noise (8.2 nV/√Hz), and SOIC-14/VSSOP-10 package compatibility.

Technical Context

The VCA820IDR integrates two input buffers and a current-feedback output amplifier with a multiplier core, enabling dc-coupled operation without external buffering. Its gain is set externally via RG and RF resistors, with maximum gain configurable between +2 V/V and +100 V/V (e.g., 20 dB at AV_MAX = +10 V/V).

Gain control is linear-in-dB: a 0–2 V VG input adjusts gain over ≥40 dB, with V_CTRL0 = 0.85 V and slope = 90 mV per dB. The device operates on ±5-V supplies, supports rail-to-rail output swing into 100 Ω (±3.7 V), and maintains stability with capacitive loads up to 100 pF when RS is properly selected.

Key Specifications

Pinout & Package

The VCA820IDR is available in SOIC-14 (8.65 mm × 3.91 mm) and VSSOP-10 (3.00 mm × 3.00 mm) packages. Pin functions are identical across both packages except for NC and dual supply pins; the DGS (VSSOP-10) variant consolidates V+ and V− onto dedicated pins and omits VREF and one NC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with VCA821IDR and VCA822IDR, the VCA820IDR provides the optimal balance of bandwidth (150 MHz), low noise (8.2 nV/√Hz), and dual-package flexibility-making it preferred for cost-sensitive, medium-bandwidth AGC and video line receiver designs where thermal headroom in VSSOP is acceptable.

Availability

VCA820IDR is available at Aetrix Electronics and suitable for automatic gain control (AGC) receivers, differential line receivers, pulse amplitude compensation systems, and programmable attenuators requiring stable component supply and guaranteed long-term sourcing.

Supply support for VCA820IDR 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 company specializing in analog and embedded processing technologies, with leadership in precision amplifiers, data converters, and high-speed signal chain solutions.

The VCA820IDR belongs to TI's wideband variable gain amplifier product line, designed specifically for high-fidelity, dc-coupled gain control in communications, test equipment, and imaging signal chains where linear-in-dB response and wide dynamic range are essential.

FAQ

What is the maximum gain range supported by the VCA820IDR?

The VCA820IDR supports >40-dB gain adjust range linearly in dB, with maximum gain (AV_MAX) externally set between +2 V/V and +100 V/V using RG and RF resistors. At AV_MAX = +10 V/V (20 dB), gain varies from +20 dB at VG = +2 V to –20 dB at VG = 0 V. The VCA820IDR datasheet confirms this behavior across –40°C to +85°C.

Does the VCA820IDR require external input/output buffers?

No, the VCA820IDR does not require external buffers. Its internal architecture integrates two input buffers and a current-feedback output amplifier with a multiplier core, enabling direct dc-coupled differential-to-single-ended conversion. This eliminates external op-amps in most AGC and line receiver designs, as confirmed in the VCA820IDR functional block diagram and application notes.

What are the recommended operating conditions for the VCA820IDR?

The VCA820IDR is specified for ±5-V supplies (±3.5 V minimum, ±6 V maximum), –40°C to +85°C ambient temperature, and RL ≥ 100 Ω. Quiescent current ranges from 31.5 mA to 36 mA depending on VG and temperature. These values are validated in Section 7.3 of the VCA820IDR datasheet under Recommended Operating Conditions.

How does gain control linearity perform across temperature for the VCA820IDR?

At AV_MAX = 20 dB, the VCA820IDR maintains absolute gain error within ±0.6 dB from –40°C to +85°C, with ±0.4 dB typical at +25°C. Gain control slope (VSLOPE = 90 mV/dB) and offset (VCTRL0 = 0.85 V) exhibit minimal drift, ensuring consistent logarithmic control across industrial temperature ranges as documented in the VCA820IDR electrical characteristics table.

Can the VCA820IDR drive a 50-Ω load directly?

Yes, the VCA820IDR can drive a 50-Ω load directly: its output delivers ±160 mA into short-circuit and sustains ±3.5 V swing into 100 Ω. For 50 Ω, output swing reduces to ~±3.0 V (typical), verified in Figure 46 of the VCA820IDR datasheet. Layout must minimize trace inductance and use proper decoupling to maintain stability and harmonic performance.