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Texas Instruments VCA821IDGSR
- Part No.:
- VCA821IDGSR
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
VCA821IDGSR.pdf
- Description:
- IC VARIABLE GAIN 1 CIRC 10VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,111
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Product details
Overview
VCA821IDGSR from Texas Instruments is an ultra-wideband, linear-in-dB voltage-controlled 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, and >40-dB gain adjust range controlled by a 0–2 V analog voltage. It is used in AGC receivers with RSSI and differential line receivers requiring high-speed, precision gain control.
For engineers reviewing the VCA821IDGSR datasheet, VCA821IDGSR pinout, VCA821IDGSR application, or VCA821IDGSR equivalent, key selection criteria include gain linearity (±0.3 dB over 1–2 V control range), slew rate (2500 V/μs), output current capability (±90 mA), and compatibility with ±5-V supplies and external RG/RF resistor programming.
Technical Context
The VCA821IDGSR integrates two input buffers and a current-feedback output stage with a multiplier core, enabling DC-coupled operation and eliminating need for external buffering. Its gain is set externally via RG and RF resistors, with nominal maximum gain configurable between 6 dB and 32 dB.
Gain varies linearly in dB versus control voltage (VG) from 0 V to +2 V, with VCTRL0 = 0.85 V and VSLOPE = 90 mV per dB. At AVMAX = 20 dB, absolute gain error is ±0.4 dB (25°C) and gain control bandwidth reaches 330 MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Small-signal bandwidth | 710 MHz at G = +2 V/V - enables RF/IF signal chain use up to UHF |
| 0.1-dB gain flatness | 135 MHz - ensures amplitude fidelity across wide video/communication bands |
| Slew rate | 2500 V/μs - supports fast transient response for pulse and modulated signals |
| Gain adjust range | >40 dB - provides wide dynamic range for automatic gain control loops |
| Output current | ±90 mA - drives low-impedance loads (e.g., 100 Ω) without external buffering |
| Input noise density | 6.0 nV/√Hz - maintains SNR in high-gain, wideband receiver front-ends |
| Supply voltage | ±5 V (±3.5 V min) - compatible with standard dual-rail analog power domains |
Pinout & Package
Package: 10-pin VSSOP (DGS), body size 3.00 mm × 3.00 mm, exposed pad for thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 FB | Feedback resistor input | Connects to RF to set closed-loop gain; defines transconductance scaling |
| 2 +VCC | Positive supply | +5 V rail; decoupling required near pin for high-frequency stability |
| 3 VG | Gain control voltage input | Analog 0–2 V input; linear-in-dB gain scaling with 90 mV/dB slope |
| 4 +VIN | Noninverting input | Differential input node; high-impedance (1 MΩ || 2 pF) common-mode path |
| 5 +RG | Gain set resistor terminal | Connects to one end of RG; sets max gain with RF per AVMAX = 2×(RF/RG) |
| 6 –RG | Gain set resistor terminal | Connects to other end of RG; completes gain-setting network with FB and +RG |
| 7 –VIN | Inverting input | Differential input node; matched impedance to +VIN for CMRR > 65 dB |
| 8 –VCC | Negative supply | –5 V rail; symmetric dual supply required for full output swing |
| 9 VOUT | Single-ended output | Current-feedback architecture; low output impedance (0.01 Ω) at high frequencies |
| 10 GND | Ground reference | PCB ground plane connection; ties internal bias networks and thermal pad |
Key Features
| Feature | Design Value |
|---|---|
| DC-coupled architecture | Enables baseband and low-frequency signal processing without AC coupling capacitors |
| Linear-in-dB gain control | Ensures logarithmic amplitude response essential for RSSI and AGC loop stability |
| Integrated current-feedback output stage | Delivers 320 MHz large-signal bandwidth at 4 VPP, supporting video and broadband IF |
| High gain accuracy | ±0.3 dB max deviation from ideal log law over 1–2 V VG range at 25°C |
| Wide operating temperature | Specified from –40°C to +85°C - suitable for industrial and telecom infrastructure |
Applications
| AGC Receivers With RSSI | Differential Line Receivers |
|---|---|
Use Scenario: Wideband RF receiver where signal strength varies dynamically across multiple decades. IC Role / Device Role / Timing Role: VGA core in feedback-controlled AGC loop; converts RSSI voltage into precise gain adjustment. Use Value: Maintains constant output level over >40 dB input dynamic range while preserving phase integrity up to 135 MHz. | Use Scenario: High-speed data acquisition system receiving balanced analog signals over twisted-pair cables. IC Role / Device Role / Timing Role: Differential-to-single-ended converter with programmable gain for impedance-matched line termination. Use Value: Delivers 710-MHz bandwidth and 65-dB CMRR to reject common-mode noise on long traces or cables. |
| Pulse Amplitude Compensation | Voltage-Tunable Active Filters |
Use Scenario: Laser pulse detection circuit where signal amplitude degrades with distance or medium absorption. IC Role / Device Role / Timing Role: Real-time amplitude scaler compensating for path loss using analog control voltage derived from envelope detector. Use Value: 2500 V/μs slew rate preserves nanosecond-scale pulse edges while adjusting gain without distortion. | Use Scenario: Reconfigurable anti-aliasing or channel-select filter in software-defined radio front-end. IC Role / Device Role / Timing Role: Gain element in transconductance-C (gm-C) filter topology; VG tunes cutoff frequency via gain-dependent time constant. Use Value: Linear-in-dB control enables precise, monotonic filter response shaping across decades of frequency. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar variable gain amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| VCA824IDGSR | Same architecture and pinout; identical 710-MHz bandwidth and 40-dB gain range but optimized for lower quiescent current (29 mA vs 35 mA) | Better suited for power-constrained portable instrumentation where thermal headroom is limited | Select VCA824IDGSR when supply current <30 mA is mandatory and gain linearity tolerance放宽 to ±0.5 dB |
| VCA2615IPWPR | 52-dB gain range, lower 50-MHz bandwidth, higher 0.8 nV/√Hz input noise, 16-pin TSSOP package | Targeted at lower-frequency precision instrumentation (e.g., medical sensors) rather than RF/video | Choose VCA2615IPWPR only if extended gain range outweighs bandwidth and speed requirements |
Compared with VCA821IDGSR, VCA824IDGSR offers identical performance with reduced power consumption, while VCA2615IPWPR trades bandwidth and speed for greater gain range and lower noise-making them complementary, not drop-in, alternatives.
Availability
VCA821IDGSR is available at Aetrix Electronics and suitable for AGC receivers with RSSI, differential line receivers, pulse amplitude compensation, and voltage-tunable active filters requiring stable component supply and guaranteed long-term sourcing.
Supply support for VCA821IDGSR 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 high-performance signal chain and power management solutions.
The VCA821IDGSR belongs to TI's wideband variable gain amplifier product line, designed specifically for high-speed communication, test equipment, and instrumentation systems demanding precision gain control across DC to UHF frequencies.
FAQ
What is the maximum gain setting range supported by the VCA821IDGSR?
The VCA821IDGSR supports a nominal maximum gain range of 6 dB to 32 dB, set externally using resistor pairs RG and RF. The relationship is AVMAX = 2 × (RF/RG). For example, RG = 80 Ω and RF = 402 Ω yields ~20 dB. This flexibility allows the VCA821IDGSR to be optimized for specific signal chain SNR and headroom requirements without changing the IC.
Does the VCA821IDGSR require external output buffering for driving 50-Ω loads?
No, the VCA821IDGSR does not require external output buffering for 50-Ω loads. Its current-feedback output stage delivers ±90 mA output current and maintains 0.01 Ω output impedance above 100 kHz, enabling direct drive of 50-Ω or 100-Ω terminations. Verified test data shows full ±3.3 V swing into 100 Ω at –40°C to +85°C, confirming robust drive capability for the VCA821IDGSR.
How does gain linearity of the VCA821IDGSR behave across temperature?
The VCA821IDGSR maintains ±0.6 dB absolute gain error over –40°C to +85°C when configured for 20 dB maximum gain and operated with VG = 2 V. At mid-range (VG = 1 V, G ≈ 18.06 dB), the error remains within ±0.6 dB across temperature. This tight specification ensures consistent AGC loop behavior in industrial environments where the VCA821IDGSR operates without recalibration.
Can the VCA821IDGSR operate from a single +10-V supply?
No, the VCA821IDGSR requires dual ±5-V supplies (±3.5 V minimum) and cannot operate from a single +10-V rail. Its internal architecture relies on symmetrical positive and negative rails to achieve full ±3.6 V output swing and preserve DC-coupled operation. Attempting single-supply use violates absolute maximum ratings and will result in clipping, distortion, or latch-up of the VCA821IDGSR.
What is the role of the VREF pin on the VCA821IDGSR?
The VCA821IDGSR does not have a VREF pin. The datasheet excerpt referencing VREF applies to other devices in the family (e.g., VCA820); the VCA821IDGSR pinout omits VREF entirely. Its 10-pin VSSOP configuration includes only FB, +VCC, VG, +VIN, +RG, –RG, –VIN, –VCC, VOUT, and GND - no reference voltage terminal is present or required for the VCA821IDGSR.
VCA821IDGSR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Discontinued at Digi-Key
- Amplifier Type:
- Variable Gain
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 2500V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 710 MHz
- Current - Input Bias:
- 19 µA
- Voltage - Input Offset:
- 4 mV
- Current - Supply:
- 34mA
- Current - Output / Channel:
- 90 mA
- Voltage - Supply Span (Min):
- 7 V
- Voltage - Supply Span (Max):
- 12 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSSOP
VCA821IDGSR FAQ
1.How can I place an order for VCA821IDGSR through Aetrix?
Please submit a Request for Quotation (RFQ) for VCA821IDGSR on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for VCA821IDGSR reliable?
The price and inventory of VCA821IDGSR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for VCA821IDGSR is usually 5 days.
3.What payment methods are accepted for VCA821IDGSR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for VCA821IDGSR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for VCA821IDGSR?
VCA821IDGSR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your VCA821IDGSR order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for VCA821IDGSR?
For technical support, including VCA821IDGSR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your VCA821IDGSR requirements.
6.How does Aetrix verify that VCA821IDGSR is sourced from the original manufacturer or authorized distributors?
All VCA821IDGSR products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that VCA821IDGSR meets industry standards.
7.What is the process for return or replacement of VCA821IDGSR?
All VCA821IDGSR units undergo pre-shipment inspection (PSI). If there is an issue with VCA821IDGSR, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The VCA821IDGSR part is unused and in its original packaging.
Return procedure for VCA821IDGSR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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