Analog Devices Inc. AD8370AREZ

Overview

AD8370AREZ from Analog Devices is a digitally controlled variable gain amplifier (VGA) optimized for IF and RF gain control in differential signal chains. It delivers −3 dB bandwidth of 750 MHz, two selectable gain ranges (−11 dB to +17 dB and +6 dB to +34 dB), 40 dB precision gain range, and 7 dB noise figure at maximum gain - enabling high-dynamic-range receiver front-ends in cable infrastructure and IF sampling systems.

For engineers reviewing the AD8370AREZ datasheet, AD8370AREZ pinout, AD8370AREZ application, or AD8370AREZ equivalent, key selection criteria include its 16-lead TSSOP package with exposed paddle, differential 200 Ω input / 100 Ω output impedance, serial 8-bit digital interface, power-down capability (<4 mA), and operation across −40°C to +85°C.

Technical Context

The AD8370AREZ implements a three-stage architecture: a gain-range-selectable preamplifier (MSB-controlled), a 7-bit vernier transconductance stage offering <2 dB resolution in high-gain mode and <1 dB in low-gain mode, and a fixed-gain output amplifier. Its XFCB bipolar process enables stable 750 MHz bandwidth across all gain codes while maintaining low distortion.

Gain is set via an 8-bit serial word: MSB selects between high/low gain modes (17 dB offset), and the remaining 7 bits adjust gain linearly in precise steps (0.409 V/V/code in high mode, 0.056 V/V/code in low mode). Power-up is controlled by the PWUP pin, and quiescent current is 78 mA typical at 5 V.

Key Specifications

Pinout & Package

AD8370AREZ is housed in a thermally enhanced 16-lead TSSOP package (4.4 mm × 5.0 mm × 1.2 mm) with exposed paddle for improved heat dissipation and grounded ICOM connection.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar VGA applications.

Compared with AD8375ACPZ-R7 and LMH6401IRGTR, the AD8370AREZ offers the best balance of 750 MHz bandwidth, 40 dB digital gain range, low 7.2 dB noise figure, and 3.0–5.5 V flexible supply - making it ideal for cost-sensitive, thermally constrained IF gain control where precise digital AGC and power-down are essential.

Availability

AD8370AREZ is available at Aetrix Electronics and suitable for cable infrastructure, IF sampling receivers, and SAW filter interfacing requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for AD8370AREZ 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, serving precision instrumentation, communications, and industrial markets.

The AD8370AREZ belongs to Analog Devices' RF/IF VGA product line, designed specifically for digitally programmable gain control in high-linearity, wideband receiver signal chains from baseband through 750 MHz.

FAQ

What is the maximum operating frequency of the AD8370AREZ?

The AD8370AREZ has a −3 dB bandwidth of 750 MHz, verified across its full 40 dB gain range and operating temperature (−40°C to +85°C). Performance remains stable up to this frequency with ≤±0.04 dB gain flatness at 240 MHz and usable response beyond 750 MHz - making it suitable for DOCSIS 3.1, LTE, and wideband IF applications. The AD8370AREZ does not specify operation above 750 MHz in datasheet conditions.

Does the AD8370AREZ support 3.3 V operation?

Yes, the AD8370AREZ operates from a single supply of 3.0 V to 5.5 V. At 3.3 V, it maintains full functionality including 750 MHz bandwidth, 40 dB gain range, and serial digital interface timing - though output IP3 degrades slightly to 33 dBm and noise figure increases to 7.4 dB at 140 MHz. The AD8370AREZ datasheet explicitly validates 3 V operation in Section "3 V Operation" (Page 20).

How is gain controlled on the AD8370AREZ?

The AD8370AREZ uses an 8-bit serial digital interface: the MSB selects between low-gain (−11 dB to +17 dB) and high-gain (+6 dB to +34 dB) modes, while the remaining 7 bits adjust gain in precise linear steps (0.409 V/V/code in high mode, 0.056 V/V/code in low mode). Data is clocked in on CLCK rising edges while LTCH is low, then latched on the next LTCH high transition. This interface is implemented directly in the AD8370AREZ silicon with no external components required.

Can the AD8370AREZ drive a 50 Ω single-ended load?

The AD8370AREZ is optimized for 100 Ω differential loads and does not natively support 50 Ω single-ended operation. Driving a 50 Ω single-ended load would require external balun or resistor network, degrading noise figure, OIP3, and gain accuracy. Its specified output performance (e.g., 35 dBm OIP3, ±0.02 dB flatness) applies only to 100 Ω differential loads per the AD8370AREZ datasheet test conditions. For 50 Ω systems, consider redesigning the interface or selecting a different amplifier.

What is the thermal performance of the AD8370AREZ package?

The AD8370AREZ uses a 16-lead TSSOP with exposed paddle, achieving θ_JA = 30°C/W when the paddle is soldered to a minimum 1 cm² copper pour. At 78 mA quiescent current and 5 V supply, power dissipation is ~390 mW, resulting in ~12°C junction-to-ambient rise above board temperature - well within the 150°C max junction rating. Thermal derating is unnecessary below +85°C ambient if the paddle is properly soldered, as confirmed in AD8370AREZ datasheet Table 2 and Package Considerations (Page 17).