Analog Devices Inc. AD8047ARZ

Overview

AD8047ARZ from Analog Devices is a unity-gain-stable, voltage-feedback operational amplifier optimized for high-speed signal conditioning in precision analog front-ends. It delivers 250 MHz small-signal bandwidth, 130 MHz large-signal bandwidth (2 V_p-p), 750 V/µs slew rate, and –54 dBc third-harmonic distortion at 20 MHz - enabling use as an input driver for 12-bit/10 MSPS ADCs in professional video and communications systems.

For engineers reviewing the AD8047ARZ datasheet, AD8047ARZ pinout, AD8047ARZ application, or AD8047ARZ equivalent, key selection criteria include its unity-gain stability, SOIC-8 package compatibility, 5.8 mA quiescent current, and verified performance driving 50 pF capacitive loads without external compensation.

Technical Context

The AD8047ARZ employs a proprietary voltage-feedback architecture that achieves current-feedback–class pulse response (30 ns to 0.01% with 2 V step) while retaining balanced high-impedance inputs for flexible active filter design. Its open-loop gain rolls off at ~6 dB/octave, yielding a constant gain-bandwidth product of ~180 V·MHz.

It operates from ±3 V to ±6 V supplies, features 5.2 nV/√Hz input voltage noise and 1.0 pA/√Hz input current noise, and maintains stable operation into 100 Ω loads with 50 mA output drive capability - all within the industrial temperature range (–40°C to +85°C).

Key Specifications

Pinout & Package

AD8047ARZ is housed in an 8-lead SOIC (R-8) package with standard 1.27 mm pitch, 5.0 mm × 6.2 mm body size, and exposed pad not present. Pin 1 is marked by a beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed voltage-feedback op amp applications.

Compared with AD8048ARZ and LMH6702MA/NOPB, AD8047ARZ uniquely combines unity-gain stability, 250 MHz bandwidth, and sub-6 mA quiescent current - making it the only option among the three viable for low-power, gain-of-one video and ADC driver applications without redesigning feedback networks.

Availability

AD8047ARZ is available at Aetrix Electronics and suitable for professional video infrastructure, high-speed data acquisition, and industrial signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD8047ARZ 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

Analog Devices, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Wilmington, MA.

The AD8047ARZ belongs to the AD804x family of wideband voltage-feedback op amps, designed specifically for demanding high-speed signal acquisition, video line driving, and precision ADC/DAC interface applications where unity-gain stability and low distortion are essential.

FAQ

What is the maximum capacitive load the AD8047ARZ can drive without external compensation?

The AD8047ARZ is specified to drive up to 50 pF capacitive load directly while maintaining stability and specified transient performance. For loads exceeding 25 pF, Analog Devices recommends adding a small series resistor (typically 5–20 Ω) at the output to suppress potential peaking - though full 50 pF drive capability is validated per Figure 59 in the AD8047/AD8048 datasheet Rev. B. This makes AD8047ARZ suitable for direct connection to ADC inputs, long PCB traces, or moderate fanout without added components.

Is the AD8047ARZ unity-gain stable, and how is this confirmed in the datasheet?

Yes, the AD8047ARZ is explicitly unity-gain stable, as stated in the General Description: "The AD8047 is unity gain stable." This is further confirmed by electrical test conditions specifying AV = +1 for AD8047 parameters in Table 1, by Figure 7 (noninverting G = +1 configuration), and by the absence of minimum gain requirements in Absolute Maximum Ratings or Application sections. In contrast, AD8048ARZ requires AV ≥ +2 for stability - confirming AD8047ARZ's unique suitability for buffer and follower topologies.

What supply voltage range does the AD8047ARZ support, and what is its typical quiescent current?

The AD8047ARZ operates from ±3 V to ±6 V dual supplies, with a typical quiescent current of 5.8 mA per amplifier - measured at ±5 V supplies per Table 1. This current remains stable across temperature (±7.5 mA max over –40°C to +85°C) and supports low-power system architectures. The supply range allows compatibility with legacy ±5 V rails and modern low-voltage ±3 V systems, while the modest current draw enables thermal management in dense PCB layouts without forced air cooling.

Can the AD8047ARZ be used to drive a 75 Ω video load, and what performance metrics validate this?

Yes, the AD8047ARZ is qualified for 75 Ω video line driving, as demonstrated in Figure 62 (Video Line Driver) and quantified by differential gain error of 0.02% and differential phase error of 0.03° at 3.58 MHz into 150 Ω - a standard test condition representative of 75 Ω terminated systems. Its 250 MHz bandwidth, 750 V/µs slew rate, and ability to deliver ±2.8 V into 150 Ω ensure full-swing NTSC/PAL/HD-SDI signal integrity. Application note CN-0270 further validates AD8047ARZ in SMPTE-compliant video paths.

Does the AD8047ARZ have any unused pins, and how should they be handled in PCB layout?

Yes, AD8047ARZ has three no-connect pins: Pin 1 (NC), Pin 5 (NC), and Pin 8 (NC). Per Table 3 in the datasheet, these pins are internally unconnected and must remain electrically floating. They may be left un-routed or tied to ground solely for mechanical reinforcement - but never connected to supply, signal, or bias networks. Leaving them unconnected avoids unintended parasitic coupling; grounding them improves solder joint reliability in reflow processes without affecting electrical performance.