ADA4805-1ARJZ-R7 - 105MHz Low-Noise Op Amp, 500µA IQ | ADI
N.º da peça: ADA4805-1ARJZ-R7 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $2.25 | $2,25 |
| 10 | $2.02 | $20,20 |
| 100 | $1.81 | $181,00 |
| 500 | $1.62 | $810,00 |
| 1.000 | $1.44 | $1.440,00 |
ADA4805-1ARJZ-R7 Visão geral
A voltage-feedback operational amplifier (VFA) is a type of op amp whose closed-loop bandwidth depends primarily on the feedback resistor and gain setting, rather than on the gain itself. The ADA4805-1 belongs to the VFA topology within the broader operational amplifier family, which itself sits under the analog signal-conditioning hierarchy: op amp -> amplifier IC -> analog IC -> semiconductor. This category also includes current-feedback amplifiers (CFAs), zero-drift chopper amplifiers, and instrumentation amplifiers, each optimized for different signal-chain roles.
Key features include 1 mA typical output current drive, 170 V/µs slew rate, rail-to-rail output swing to within 40 mV of either rail at light load, and internal RF input filtering. The SOT-23-6 (RJ-6) footprint is approximately 2.9 mm × 1.6 mm with exposed thermal considerations managed through the lead frame. Offset drift of 0.2 µV/°C enables precision DC accuracy over industrial temperature ranges of -40 °C to +125 °C.
The internal architecture uses a complementary bipolar input stage with rail-to-rail output common-emitter design, allowing the amplifier to swing within millivolts of either supply rail. The 5.2 nV/√Hz input voltage noise combined with 105 MHz bandwidth gives an amplifier noise figure competitive with parts consuming 5-10× more current. This efficiency is critical for portable and battery-powered precision instrumentation.
Typical applications include active filters for anti-aliasing, ADC drivers for high-resolution successive-approximation register (SAR) converters, photodiode transimpedance stages, and portable medical instrumentation front ends. The wide supply range also makes it suitable for handheld test equipment and industrial sensor conditioning.
When designing with this part, account for thermal dissipation in the small SOT-23 package: at 10 V supply and 30 mA load the part dissipates 300 mW. A solid ground plane and short input traces are essential to maintain 105 MHz performance without oscillation.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes that go beyond the manufacturer datasheet, giving engineers a single source for sourcing, substitution, and design-in decisions.
Alternativas drop-in para ADA4805-1ARJZ-R7 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
ADA4805-1AKSZ-R7
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADA4805-1ARJZ-R2
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADA4860-1YRJZ-R7
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADA4897-1ARJZ-R7
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADA4851-1YRJZ-R7
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
ADA4805-1ARJZ-R7 Classificações máximas e características elétricas
| Manufacturer | Analog Devices |
| Amplifier Type | Voltage Feedback |
| Number of Circuits | 1 |
| Tipo de saída | Rail-to-Rail |
| -3 dB Bandwidth | 105 MHz |
| Slew Rate | 170 V/µs |
| Input Voltage Noise Density | 5.2 nV/√Hz |
| Input Offset Voltage (typical) | 1.6 mV |
| Offset Drift | 0.2 µV/°C |
| Quiescent Current (typical) | 500 µA |
| Supply Voltage Range (dual) | ±1.5 V to ±5 V |
| Supply Voltage Range (single) | 3 V to 10 V |
| Output Current | 1 mA typical |
| Faixa de temperatura de operação | -40 °C to +125 °C |
| Encapsulamento | SOT-23-6 (RJ-6) |
| Tipo de montagem | Surface Mount |
| Status RoHS | Compliant |
| Nível MSL | 1 (unlimited) |
Configuração de pinos do ADA4805-1ARJZ-R7
| Pino 1 | OUT — Amplifier output (rail-to-rail) |
| Pino 2 | V- — Negative power supply (or GND for single-supply) |
| Pino 3 | +IN — Non-inverting input |
| Pino 4 | V+ — Positive power supply |
| Pino 5 | NC — Not connected (per datasheet) |
| Pino 6 | -IN — Inverting input |
Aplicações típicas
ADA4805-1ARJZ-R7 é adequado para 6 aplicaçãos: 16-bit SAR ADC Driver, Active Anti-Aliasing Filter, Photodiode Transimpedance Amplifier, Portable Test & Measurement Front-End, Industrial Sensor Signal Conditioning, Medical Instrumentation Buffer.
16-bit SAR ADC Driver
The ADA4805-1ARJZ-R7's 105 MHz bandwidth, 170 V/µs slew rate, and 500 µA low quiescent current make it an excellent driver front-end for 16-bit SAR ADCs sampling at 1 MSPS or below. The 5.2 nV/√Hz input noise contributes negligible degradation to overall SNR when properly filtered, and the rail-to-rail output swing maximizes dynamic range on 3.3 V or 5 V supply rails. The op amp is placed in unity-gain buffer configuration between the input source and the ADC, with a series resistor and ADC input capacitor forming a charge-kickback RC filter. Compared to a CFA, the VFA topology eliminates current-feedback distortion artifacts, which is critical at 16-bit precision.
Recomendado
Active Anti-Aliasing Filter
The 105 MHz gain-bandwidth product makes the ADA4805-1ARJZ-R7 well suited as an active filter building block for second-order or higher Butterworth, Bessel, or Chebyshev low-pass filters above 100 kHz cutoff. The 170 V/µs slew rate ensures clean transient response with minimal slew-induced distortion on fast input edges. At filter cutoff frequencies up to 1 MHz, the op amp provides 60 dB of stopband attenuation with proper Sallen-Key or multiple-feedback topology selection. Low 500 µA quiescent current enables multi-pole active filters in portable instrumentation without excessive battery drain.
Recomendado
Photodiode Transimpedance Amplifier
The ADA4805-1ARJZ-R7 works as a wideband transimpedance amplifier for PIN photodiode front-ends in fiber-optic receivers and pulse-oximetry sensors. At feedback resistors of 10-100 kΩ, the -3 dB bandwidth extends to several MHz, supporting 100 Mbps optical data links. The 5.2 nV/√Hz input noise ensures the receiver noise floor is dominated by the feedback resistor thermal noise rather than the amplifier. The 0.2 µV/°C offset drift keeps DC baseline stable across temperature swings in industrial sensing environments.
Recomendado
Portable Test & Measurement Front-End
With 500 µA quiescent current and rail-to-rail output from 3 V to 10 V single supply, the ADA4805-1ARJZ-R7 is designed into handheld oscilloscope front-ends, bench multimeter input buffers, and battery-powered spectrum analyzer signal paths. The 105 MHz bandwidth exceeds the 20-100 MHz analog front-end requirement of most portable instruments, while the SOT-23-6 footprint fits tight PCB layouts typical of handheld products. Low quiescent current contributes to Li-ion battery runtimes of 8+ hours in continuous measurement instruments.
Recomendado
Industrial Sensor Signal Conditioning
Industrial 4-20 mA current loops, RTD bridge outputs, and strain gauge amplifiers all benefit from the ADA4805-1ARJZ-R7's combination of low offset drift (0.2 µV/°C) and wide supply range (±1.5 V to ±5 V) supporting 24 V industrial bus compatibility. The amplifier can be used in instrumentation front-ends, active load-cell excitation buffers, and PLC analog input stages. The -40 °C to +125 °C operating temperature range meets harsh industrial environment requirements without thermal conditioning.
Recomendado
Medical Instrumentation Buffer
The ADA4805-1ARJZ-R7 is used in medical ECG, pulse-oximeter, and ultrasound receiver signal chains where low noise and low power are both required. With 5.2 nV/√Hz input noise and 500 µA IQ, the part meets IEC 60601-1 patient-safety current budgets while delivering 105 MHz bandwidth for diagnostic-frequency signal integrity. The rail-to-rail output maximizes ADC dynamic range on 3.3 V supply rails common in wearable medical devices. Solid PCB grounding with separate analog/digital ground planes is recommended to maintain 16-bit precision in patient monitoring applications.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para ADA4805-1ARJZ-R7 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | ADA4805-1AKSZ-R7 | ADA4805-1ARJZ-R2 | ADA4860-1YRJZ-R7 | ADA4897-1ARJZ-R7 | ADA4851-1YRJZ-R7 |
|---|---|---|---|---|---|---|
| Package | SOT-23-6 (RJ-6) | SC-70-6 (KS-6) - smaller footprint | SOT-23-6 (RJ-6) - identical | SOT-23-6 (RJ-6) - identical | SOT-23-6 (RJ-6) - identical | SOT-23-6 (RJ-6) - identical |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Bandwidth (-3 dB) | 105 MHz | 105 MHz | 105 MHz | 120 MHz | 230 MHz | 70 MHz |
| Quiescent Current | 500 µA | 500 µA | 500 µA | 6 mA | 3 mA | 2.5 mA |
| Input Voltage Noise | 5.2 nV/√Hz | 5.2 nV/√Hz | 5.2 nV/√Hz | 3.5 nV/√Hz | 1 nV/√Hz | 6 nV/√Hz |
| Slew Rate | 170 V/µs | 170 V/µs | 170 V/µs | 480 V/µs | 1200 V/µs | 1000 V/µs |
| Output Type | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail |
| Channels | 1 | 1 | 1 | 1 | 1 | 1 |
| Supply Range | 3 V to 10 V single / ±1.5 V to ±5 V dual | 3 V to 10 V single | 3 V to 10 V single | 5 V to 12 V single | 5 V to 12 V single | 3 V to 12 V single |
Principais diferenciais
- Lowest quiescent current in 100+ MHz op amp category (vs ADA4860-1YRJZ-R7)
- Wider supply range including 3 V single-supply (vs ADA4897-1ARJZ-R7)
- Single-channel version in compact 6-pin package (vs ADA4805-2ARMZ-R7)
Notas de projeto
Estimated: At 10 V supply and full 1 mA typical load, the ADA4805-1 dissipates approximately 10 mW in the SOT-23-6 package with theta_JA around 220 °C/W. Junction temperature rise above ambient is ~2.2 °C, well within the 125 °C operating limit. For higher output currents or elevated ambient temperatures, ensure the SOT-23-6 PCB pad layout provides sufficient copper thermal relief - minimum 1 square cm copper pour per side. The SOT-23-6 (RJ-6) package has no exposed thermal pad, so all heat dissipation occurs through the six signal leads.
For 105 MHz stable operation, use a solid uninterrupted ground plane beneath the part and keep input traces as short as possible. Place a 0.1 µF ceramic bypass capacitor within 3 mm of the V+ pin (Pin 4) and a 10 µF bulk capacitor nearby. For ADC driving applications, add a 50-100 Ω series resistor between op amp output and ADC input to isolate the op amp output stage from the ADC's switched-capacitor load kickback. Do not route digital signals under the amplifier pins or near the input traces.
Do not assume the ADA4805-1 can drive heavy capacitive loads directly: the part is unity-gain stable but capacitive loads above 50 pF may cause peaking. For 100% stable performance at higher capacitive loads (e.g., long cables), add a small series resistor (10-50 Ω) at the output. Also note that the V- pin (Pin 2) must always be connected to a clean supply return - floating this pin will result in undefined operation. Single-supply operation requires V- to be tied to ground, with input common-mode range limited to V- + 0.5 V to V+ - 0.5 V.
Informações de conformidade
RoHS compliant per Analog Devices product page and distributor listings. AEC-Q100 not applicable - this is a commercial/industrial grade op amp, not automotive qualified.
