Analog Devices Inc. AD8156ABCZ

Overview

AD8156ABCZ from Analog Devices is a 4 × 4 fully differential digital crosspoint switch with integrated input equalization, supporting NRZ data rates up to 6.25 Gbps per channel. It operates on 3.3 V ±10%, delivers programmable differential output swing (100 mV–1.6 V p-p), features low additive jitter (25 ps p-p), and integrates 50 Ω termination at all inputs/outputs for backplane signal integrity in high-speed serial interconnects.

For engineers reviewing the AD8156ABCZ datasheet, AD8156ABCZ pinout, AD8156ABCZ application, or AD8156ABCZ equivalent, key selection considerations include its dual-mode operation (4×4 or dual 2×2), per-channel input EQ gain up to 23 dB at 3.125 GHz, individual output disable capability, and BGA-49 package compatibility with FR-4 backplanes up to 40 inches at 6.25 Gbps.

Technical Context

The AD8156ABCZ implements a double-latched memory architecture enabling simultaneous configuration updates without data interruption in 4×4 mode. Its input equalization uses a linear-in-dB active scheme with 15 programmable gain steps (0–23 dB) and a 40 dB/decade slope, optimized for compensating loss in long FR-4 traces.

In dual 2×2 mode, asynchronous control via A[3:0]/D[3:0] enables sub-10 ns output switching, while retaining EQ and output current settings configured previously in 4×4 mode. All high-speed I/O supports ac- or dc-coupled CML (3.3 V/2.5 V/1.8 V) and LVPECL (3.3 V) standards, with LVTTL/LVCMOS-compatible control logic.

Key Specifications

Pinout & Package

AD8156ABCZ is housed in a 49-ball, 8 mm × 8 mm CSP_BGA package with 1 mm ball pitch, optimized for minimal trace inductance and controlled impedance routing on multilayer PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digital crosspoint switch applications.

Compared with MAX9157ETJ+T and DS10BR254, the AD8156ABCZ uniquely combines 6.25 Gbps per-port bandwidth, per-channel programmable equalization, and dual operational modes in a single BGA package-enabling both high-density routing and rapid protection switching without hardware redesign.

Availability

AD8156ABCZ is available at Aetrix Electronics and suitable for backplane equalization, SONET/SDH line cards, and Fibre Channel storage interconnects requiring stable component supply across extended product lifecycles.

Supply support for AD8156ABCZ 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 is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and RF technologies for precision signal processing.

The AD8156ABCZ belongs to Analog Devices' Xstream family of high-speed interconnect ICs, designed specifically for signal integrity restoration and flexible routing in telecom, datacom, and test equipment backplanes.

FAQ

What data rates does the AD8156ABCZ support, and how is performance verified?

The AD8156ABCZ supports NRZ data rates from DC to 6.25 Gbps per channel. Performance is verified per Analog Devices Rev. 0 datasheet specifications: deterministic jitter is 25 ps p-p typical at 6.25 Gbps, and eye height remains ≥400 mV at full rate over 40" FR-4 with optimal EQ enabled. These values are measured under defined conditions (PRBS223−1, 800 mV p-p differential swing, TA = 25°C) and confirmed in Figures 10, 13, and 17 of the AD8156ABCZ datasheet.

How does the AD8156ABCZ handle input signal degradation over long FR-4 traces?

The AD8156ABCZ mitigates FR-4 loss using a programmable 15-step input equalizer delivering up to 23 dB gain at 3.125 GHz. This compensates for >40" of FR-4 including connectors and vias at 6.25 Gbps, reducing residual deterministic jitter to 0.15 UI p-p. The equalizer's 40 dB/decade slope and linear-in-dB response are calibrated to match typical backplane transfer functions, as validated in Figures 14 and 19 of the AD8156ABCZ datasheet.

Can the AD8156ABCZ operate in both 4×4 and dual 2×2 modes, and what are the trade-offs?

Yes, the AD8156ABCZ toggles between 4×4 and dual 2×2 modes via the MODE pin. In 4×4 mode, it offers full programmability (EQ, output swing, broadcast control) with double-latched updates. In dual 2×2 mode, it provides sub-10 ns channel switching using A[3:0]/D[3:0] pins, but EQ and swing settings are retained-not adjustable. Mode switching retains configuration, enabling hybrid use cases as documented in Theory of Operation (Pages 13–14 of AD8156ABCZ datasheet Rev. 0).

What power supply requirements does the AD8156ABCZ have, and how does power vary with configuration?

The AD8156ABCZ requires VCC = 3.3 V ±10% and separate VTTI/VTTO termination supplies. Power dissipation ranges from 60 mW (all disabled) to 700 mW (all outputs + EQ active), with typical values of 400 mW (outputs only) and 700 mW (full EQ + outputs). Supply currents are specified in Table 1: ICC1 = 141 mA max with all EQ and outputs enabled, as confirmed in the Electrical Specifications section of the AD8156ABCZ datasheet.

Is the AD8156ABCZ pinout compatible with other Analog Devices crosspoint switches?

No, the AD8156ABCZ uses a unique 49-ball CSP_BGA pinout (8 mm × 8 mm, 1 mm pitch) optimized for its 4×4 differential I/O and control interface. Pin assignments-including dedicated VTTI/VTTO supplies, MODE, UPD, and dual-bank control signals-are specific to this device and not shared with earlier AD815x or ADN28xx families. Layout reuse requires direct reference to Figure 7 and Table 5 in the AD8156ABCZ datasheet Rev. 0.