Analog Devices Inc. ADN4651BRSZ

Overview

ADN4651BRSZ from Analog Devices is a dual-channel, 3.75 kVRMS galvanically isolated LVDS buffer supporting up to 600 Mbps data rates with 4.5 ns max propagation delay, 151 ps peak-to-peak total jitter at 600 Mbps, and fail-safe output high for open/short/terminated inputs. It operates from 2.5 V or 3.3 V supplies and is used in isolated high-speed serial links such as SPI over LVDS and data plane isolation in industrial AFEs.

For engineers reviewing the ADN4651BRSZ datasheet, ADN4651BRSZ pinout, ADN4651BRSZ application, or ADN4651BRSZ equivalent, key selection criteria include its 20-lead SSOP package with 3.75 kVRMS isolation, dual-channel LVDS channel directionality (input-side DIN1±/DIN2±, output-side DOUT1±/DOUT2±), fail-safe timing (1.2 µs delay), and compliance with TIA/EIA-644-A and IEC/CSA 62368-1.

Technical Context

The ADN4651BRSZ integrates iCoupler® technology to provide galvanic isolation between two independent LVDS channels, each with dedicated input and output sides. Its internal LDO accepts 3.3 V input (VIN1/VIN2) and regulates to 2.5 V (VDD1/VDD2) for low-jitter operation, while maintaining full TIA/EIA-644-A differential signaling compliance on both sides of the barrier.

Unlike the ADN4650 and ADN4652 variants, the ADN4651BRSZ features cross-coupled channel mapping: DIN1± and DIN2± reside on Side 1 (GND1/VDD1), while DOUT1± and DOUT2± reside on Side 2 (GND2/VDD2), enabling bidirectional signal flow across the isolation barrier. Fail-safe logic ensures DOUTx± drives high when |VID| < 100 mV on corresponding DINx± inputs.

Key Specifications

Pinout & Package

ADN4651BRSZ is housed in a 20-lead SSOP package (body width 5.3 mm) with creepage and clearance of 5.3 mm, rated for 3.75 kVRMS isolation. Pin numbering follows standard SSOP convention with GND1 and GND2 on opposite sides of the isolation barrier.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADN4651WRSZ, the ADN4651BRSZ offers identical performance but lacks automotive qualification; compared with ISO6721DWR, it delivers 12× higher data rate, LVDS compliance, and fail-safe logic - making it essential for precision high-speed isolation.

Availability

ADN4651BRSZ is available at Aetrix Electronics and suitable for analog front-end isolation, data plane isolation, and isolated SPI over LVDS applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for ADN4651BRSZ 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 ADN465x family is part of Analog Devices' iCoupler® isolated interface portfolio, designed specifically for high-speed, low-jitter galvanic isolation of LVDS signals in industrial, medical, and test equipment.

FAQ

What is the isolation rating and package type of the ADN4651BRSZ?

The ADN4651BRSZ has a 3.75 kVRMS isolation rating for 1 minute and is packaged in a 20-lead SSOP (Small Outline Integrated Circuit) with 5.3 mm creepage and clearance. This package meets reinforced insulation requirements per IEC/CSA 62368-1 and DIN EN IEC 60747-17 (VDE 0884-17), making it suitable for medical and industrial safety-critical applications. The ADN4651BRSZ uses this SSOP variant specifically to achieve the 3.75 kVRMS rating.

Does the ADN4651BRSZ support both 2.5 V and 3.3 V operation?

Yes, the ADN4651BRSZ supports dual-supply operation: it can be powered directly with 2.5 V on VDD1/VDD2, or with 3.3 V applied to VIN1/VIN2, which is internally regulated to 2.5 V by an integrated LDO. The LDO accepts 3.0 V to 3.6 V input and delivers 2.375 V to 2.625 V output. This flexibility allows seamless integration into systems with either 2.5 V or 3.3 V infrastructure without external regulation. The ADN4651BRSZ's LDO is enabled by default when VINx is used.

What is the fail-safe behavior of the ADN4651BRSZ and how is it triggered?

When the differential input voltage |VID| falls below 100 mV - indicating an open, shorted, or terminated-but-undriven condition - the ADN4651BRSZ asserts a logic high on the corresponding DOUTx± pair after a 1.2 µs delay. This fail-safe mechanism ensures predictable output states during faults or initialization, eliminating metastability risks in downstream receivers. The ADN4651BRSZ implements this behavior on both channels independently, and it is inherent to the device's receiver design - no external components or configuration are needed.

How does the ADN4651BRSZ differ from the ADN4650BRSZ and ADN4652BRSZ in pin configuration?

The ADN4651BRSZ places both LVDS inputs (DIN1±, DIN2±) on Side 1 (GND1/VDD1) and both outputs (DOUT1±, DOUT2±) on Side 2 (GND2/VDD2), enabling unidirectional signal flow across the barrier. In contrast, the ADN4650BRSZ locates all inputs and outputs on the same side, while the ADN4652BRSZ swaps input/output assignment per channel. This directional mapping makes the ADN4651BRSZ ideal for point-to-point isolated serial links like SPI extensions, whereas the others suit different topologies such as loopback or bidirectional channel pairing.

What regulatory certifications apply to the ADN4651BRSZ?

The ADN4651BRSZ holds UL 1577 (3750 VRMS), IEC/CSA 62368-1, IEC/CSA 60601-1 (1 MOPP), IEC/CSA 61010-1, CQC GB4943.1, and DIN EN IEC 60747-17 (VDE 0884-17) certifications. These approvals confirm compliance with reinforced insulation requirements for medical, industrial, and measurement equipment. The ADN4651BRSZ is specifically certified in the RS-20 (SSOP) variant, with VIORM = 600 VPEAK and VIOWM = 424 VRMS - critical for system-level safety certification.