Analog Devices Inc. AD1836AAS

Overview

AD1836AAS from Analog Devices is a multichannel 96 kHz audio codec IC featuring three stereo DACs and two stereo ADCs, 24-bit resolution, A-weighted dynamic range of 100–105 dB (RMS), –92 dB THD+N for ADCs and –95 dB THD+N for DACs, and differential analog I/O for noise immunity - deployed in home theater systems for high-fidelity multichannel playback and recording.

For engineers reviewing the AD1836AAS datasheet, AD1836AAS pinout, AD1836AAS application, or AD1836AAS equivalent, key selection considerations include A-weighted SNR performance, 52-lead MQFP package compatibility, TDM 8-in/8-out auxiliary interface support, SPI-controlled volume ramping, and programmable PGA gain for ADC inputs.

Technical Context

The AD1836AAS implements patented multibit Σ-Δ architecture with independent decimation (ADC) and interpolation (DAC) filters - each offering 120 dB stop-band attenuation and linear phase response. Its dual ADC section supports three input configurations: direct differential, PGA-differential, and MUX/PGA single-ended, all configurable via SPI registers.

DAC operation supports I²S, left/right-justified, DSP, and packed TDM modes (128/256), enabling full 6-channel data routing over one DSDATA pin. Clock architecture accepts 256×/512×/768× f_S master clock inputs and includes internal clock doubling for 96 kHz mode at 256× f_S external frequency.

Key Specifications

Pinout & Package

AD1836AAS is housed in a 52-lead MQFP (PQFP) plastic package with 0.65 mm lead pitch, thermally enhanced for audio-grade thermal management (θ_JA = 45°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar multichannel audio codec applications.

Compared with AK4118VN and CS42526-CQZ, AD1836AAS uniquely delivers A-weighted 105 dB ADC dynamic range, dual-mode ADC2 (PGA/MUX), and SHARC SPORT-compatible TDM auxiliary interface - making it optimal for high-SNR, programmable, DSP-coupled multichannel audio systems where precision analog front-end control is critical.

Availability

AD1836AAS is available at Aetrix Electronics and suitable for home theater systems, automotive infotainment platforms, and DVD recorder designs requiring stable component supply, long-lifecycle assurance, and consistent parametric performance across production batches.

Supply support for AD1836AAS 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, with design centers worldwide.

The AD1836AAS belongs to Analog Devices' high-fidelity audio codec product line, engineered specifically for multichannel consumer and professional audio systems demanding low THD+N, high dynamic range, and flexible digital interface options.

FAQ

What distinguishes AD1836AAS from the standard AD1836A?

The AD1836AAS is the specific variant of the AD1836A codec characterized with A-weighted dynamic range performance: 100–105 dB (ADC) and 105–108 dB (DAC), measured per Table 2 of the Rev. A datasheet. This specification differentiates it from the AD1836ACS variant, which has lower A-weighted DR (97–102 dB). All functional, pinout, and register behavior remains identical between AD1836AAS and AD1836ACS - only the guaranteed analog performance bin differs.

Does AD1836AAS support 96 kHz operation across all ADC and DAC channels?

AD1836AAS supports 96 kHz sample rate, but with channel limitations: only the primary stereo ADC pair (ADC1L/R) and all three stereo DAC pairs operate at 96 kHz simultaneously. The secondary ADC pair (ADC2) is restricted to 48 kHz in 96 kHz system mode. This is explicitly defined in the Functional Overview section (Page 11) and confirmed by the ADC decimation ratio (64× for 96 kHz vs. 128× for 48 kHz) in the datasheet.

Can AD1836AAS interface directly with a SHARC processor's SPORT without external logic?

Yes - AD1836AAS supports a dedicated TDM auxiliary interface mode that enables glueless connection to a single SHARC SPORT, providing full 8-in/8-out capability. In this mode, pins like ABCLK, ALRCLK, DSDATA1–3, and ASDATA1–2 are reconfigured per Table 11, allowing the AD1836AAS to act as an 8-channel audio I/O expansion for the SHARC without multiplexers or level shifters.

What is the purpose of the FILTD and FILTR pins on AD1836AAS?

FILTR (Pin 13) is the voltage reference output (~2.25 V), used to bias external op-amps driving ADC inputs or receiving DAC outputs - it must be bypassed with 10 µF||100 nF to AGND. FILTD (Pin 12) is a dedicated DAC bias noise filter node, connected to a grounded capacitor to suppress internal DAC reference noise; its omission may slightly increase DAC output noise floor but is permissible in less demanding applications.

Is the SPI interface of AD1836AAS compatible with standard microcontroller peripherals?

Yes - AD1836AAS implements a 4-wire SPI-compatible control port (CCLK, CLATCH, CDATA, COUT) with Motorola-style timing and 16-bit word length. It operates asynchronously to audio clocks, supports up to 8 MHz CCLK, and is compatible with most MCU SPI peripherals when configured for CPOL=0, CPHA=0, MSB-first. However, due to an interface anomaly, writes to DAC registers immediately after ADC register reads/writes must be repeated twice to ensure execution.