Analog Devices Inc. ADA4939-2YCPZ-RL

Overview

ADA4939-2YCPZ-RL from Analog Devices is a dual, ultralow distortion differential ADC driver fabricated in SiGe bipolar process. It delivers −77 dBc HD2 and −91 dBc HD3 at 100 MHz, 2.3 nV/√Hz input voltage noise, 1.4 GHz −3 dB bandwidth (G = 2), and <1 ns overdrive recovery - enabling high-fidelity signal conditioning for 16-bit ADCs in IF/baseband data acquisition systems.

For engineers reviewing the ADA4939-2YCPZ-RL datasheet, ADA4939-2YCPZ-RL pinout, ADA4939-2YCPZ-RL application, or ADA4939-2YCPZ-RL equivalent, key selection criteria include differential gain stability ≥2, user-adjustable VOCM, single-supply operation (3.3 V to 5 V), and crosstalk ≤−80 dB at 100 MHz - critical for multichannel RF receiver front-ends and time-interleaved ADC interfaces.

Technical Context

The ADA4939-2YCPZ-RL implements dual independent voltage-feedback amplifier channels with separate VOCM, PD, and feedback paths per channel. Each channel features internal common-mode feedback that actively balances outputs and suppresses even-order harmonics while enabling precise matching to ADC input common-mode ranges.

Its SiGe process enables simultaneous high slew rate (6800 V/µs at 5 V), low input noise (2.3 nV/√Hz), and wide bandwidth (1.4 GHz small-signal) - with stable operation using external resistor networks for gains ≥2 and full rail-to-rail VOCM adjustment from 1.3 V to 3.5 V (5 V supply).

Key Specifications

Pinout & Package

The ADA4939-2YCPZ-RL is housed in a 4 mm × 4 mm, 24-lead LFCSP package with exposed pad (EPAD) requiring connection to ground for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar differential ADC driver applications.

Compared with LMH5401RTVT and THS4561IRGET, the ADA4939-2YCPZ-RL uniquely combines dual-channel integration, per-channel VOCM adjustability, and ultralow distortion (<−77 dBc HD2 at 100 MHz) - making it optimal for space-constrained, multichannel 16-bit ADC interfaces demanding precision common-mode alignment and channel-to-channel coherence.

Availability

ADA4939-2YCPZ-RL is available at Aetrix Electronics and suitable for high-speed data acquisition, communications infrastructure, medical imaging, and test equipment requiring stable component supply, long-term obsolescence management, and traceable sourcing.

Supply support for ADA4939-2YCPZ-RL 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 Norwood, MA.

The ADA4939 family targets high-resolution data conversion systems, specifically engineered to drive 14–16-bit ADCs with minimal distortion, noise, and timing uncertainty from dc to 100 MHz.

FAQ

What is the minimum stable gain for the ADA4939-2YCPZ-RL?

The ADA4939-2YCPZ-RL is stable for differential gains ≥2 when configured with standard external resistor feedback networks. Gain settings below 2 require additional compensation and are not characterized or guaranteed per the datasheet. This stability threshold ensures flat frequency response and minimal peaking up to 1.4 GHz, making ADA4939-2YCPZ-RL ideal for fixed-gain IF amplification stages in communications receivers.

Does the ADA4939-2YCPZ-RL support single-ended input operation?

Yes, the ADA4939-2YCPZ-RL supports single-ended-to-differential conversion using either input terminal (+IN or −IN) referenced to a dc bias voltage, with the other input terminated to that same bias. The internal architecture and specified distortion performance (e.g., −102 dBc HD2 at 10 MHz) include validation under single-ended drive conditions, confirming ADA4939-2YCPZ-RL's suitability for legacy signal sources lacking differential outputs.

How does the power-down feature operate on the ADA4939-2YCPZ-RL?

The ADA4939-2YCPZ-RL provides independent power-down control per channel via PD1 and PD2 pins: logic low (≤1 V) disables the respective amplifier, reducing quiescent current to 0.32 mA; logic high (≥2 V) enables normal operation. Turn-on time is 100 ns, and turn-off time is 500 ns - enabling rapid channel gating in TDD systems without disrupting adjacent channel integrity. Both channels remain fully functional when one is powered down.

What is the thermal performance of the ADA4939-2YCPZ-RL package?

The ADA4939-2YCPZ-RL uses a 24-lead LFCSP with exposed pad, achieving θ_JA = 67 °C/W on a JEDEC 4-layer board. With 36.5 mA per amplifier at 5 V, total power dissipation is ~365 mW - resulting in ~24 °C junction-to-ambient rise under still-air conditions. The exposed pad must be soldered to a solid ground plane to realize this rating; inadequate thermal land design degrades reliability and parametric stability, especially during sustained large-signal operation.

Can the ADA4939-2YCPZ-RL drive ADC inputs with different common-mode voltage requirements per channel?

Yes, the ADA4939-2YCPZ-RL provides independent VOCM1 and VOCM2 inputs, allowing distinct common-mode output voltages for each channel. For example, VOCM1 can be set to 1.8 V for an AD9628 input while VOCM2 is set to 2.05 V for an AD9643 - enabling mixed-ADC architectures without external level shifters. The VOCM input exhibits 0.98 V/V gain and −90 dB CMRR, ensuring accurate, low-drift common-mode translation critical for multichannel synchronization.