Analog Devices Inc. AD9862BST

Overview

AD9862BST from Analog Devices is a 12-bit ADC / 14-bit DAC mixed-signal front-end (MxFE™) processor for broadband communications, featuring dual-channel receive and transmit paths, 64 MSPS ADC sampling, 128 MSPS DAC update rate, and integrated programmable gain amplifiers, Hilbert filters, and delay-locked loop clock generation. It serves as the core signal conditioning and conversion engine in cable modems and VDSL systems.

For engineers reviewing the AD9862BST datasheet, AD9862BST pinout, AD9862BST application, or AD9862BST equivalent, key selection considerations include its 12/14-bit resolution trade-off versus AD9860BST, Rx/Tx channel isolation >90 dB, 128-lead LQFP package compatibility, and support for real/I/Q baseband or low-IF architectures in fixed wireless and wireline infrastructure.

Technical Context

The AD9862BST implements a dual-path MxFE architecture with independent Rx and Tx signal chains. Each Rx channel integrates a 12-bit, 64 MSPS ADC, input buffer, 20 dB RxPGA, decimation filter, and bypassable digital Hilbert filter; each Tx channel includes a 14-bit, 128 MSPS current-output DAC, TxPGA with 20 dB range, interpolation filters (×2/×4), and digitally tunable quadrature mixers.

Timing is synchronized via an on-chip DLL clock multiplier supporting single-crystal or external clock inputs, generating internal clocks up to 128 MHz and two programmable external outputs (CLKOUT1/CLKOUT2). Device configuration uses a 3-wire SPI interface controlling over 100 registers, including auxiliary 10-bit ADCs and 8-bit DACs.

Key Specifications

Pinout & Package

AD9862BST is housed in a 128-lead Low Profile Plastic Quad Flatpack (LQFP), ST-128B package, with exposed thermal pad (not electrically connected). Pin functions are validated per Analog Devices' official pin configuration diagram and function descriptions (Rev. 0).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar mixed-signal front-end applications.

Compared with AD9860BST and AD9961BCPZ, AD9862BST delivers superior dynamic performance (72.0 dB SNR, 69.8 dB SNDR) and greater signal chain flexibility via programmable Hilbert filters and ×4 interpolation-critical for high-order QAM and OFDM in next-generation wireline systems.

Availability

AD9862BST is available at Aetrix Electronics and suitable for cable modems, VDSL line cards, and fixed wireless access equipment requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature operation.

Supply support for AD9862BST 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 AD9862BST belongs to the MxFE™ (Mixed-Signal Front-End) product line, engineered specifically for broadband communication infrastructure requiring tightly integrated, high-dynamic-range ADC/DAC functionality with programmable signal conditioning.

FAQ

What is the maximum sampling rate supported by the AD9862BST ADC?

The AD9862BST supports a maximum ADC sampling rate of 64 MSPS in normal timing mode. This rate is maintained across both receive channels simultaneously and is specified under conditions of VA = 3.3 V ±5%, VD = 3.3 V ±10%, and fADC = 64 MHz. The device also supports lower rates (32 MSPS, 16 MSPS) in low-power modes to reduce current consumption while retaining 12-bit resolution.

Does the AD9862BST support I/Q signal processing in both receive and transmit paths?

Yes, the AD9862BST supports full I/Q signal processing in both paths. Its digital Hilbert filters are independently configurable and bypassable in Rx and Tx chains, enabling complex baseband generation and image-reject demodulation. The Tx path includes digitally tunable quadrature mixers, and the Rx path accepts real, diversity, or I/Q data at baseband or low IF-verified in the functional block diagram and timing specifications.

What is the purpose of the FSADJ pin on the AD9862BST?

The FSADJ pin on the AD9862BST is used to adjust the full-scale output current of the 14-bit DACs. By connecting an external resistor between FSADJ and AGND, users can scale the nominal 20 mA full-scale current output linearly-enabling precise matching to external reconstruction filter and driver stage requirements without modifying the DAC's digital gain control.

Can the AD9862BST operate with a single crystal oscillator input?

Yes, the AD9862BST can operate with a single crystal oscillator input applied to the OSC1 pin (with OSC2 grounded or left floating per design guidelines). Its integrated delay-locked loop (DLL) multiplies the crystal frequency to generate all internal clocks-including 128 MHz for DAC operation-and provides two programmable external clock outputs (CLKOUT1, CLKOUT2), eliminating the need for multiple clock sources.

How many auxiliary analog inputs and outputs does the AD9862BST provide?

The AD9862BST provides four auxiliary ADC inputs (AUX_ADC_A1, AUX_ADC_A2, AUX_ADC_B1, AUX_ADC_B2) and three auxiliary DAC outputs (AUX_DAC_A, AUX_DAC_B, AUX_DAC_C). The auxiliary ADC is 10-bit with 1.25 MSPS conversion rate and 3 V input range; the auxiliary DACs are 8-bit with 3 V output range and 8 µs settling time-fully documented in the "Auxiliary ADC" and "Auxiliary DAC" sections of the datasheet.