Analog Devices Inc. AD7813YNZ

Overview

AD7813YNZ from Analog Devices is a 10-bit successive approximation analog-to-digital converter (ADC) with 400 kSPS throughput, on-chip track-and-hold, internal clock oscillator, and 8-bit parallel interface. It operates from a single 2.7 V to 5.5 V supply, delivers ±1 LSB relative accuracy and 58 dB SNR at 30 kHz input, and is used in microprocessor-based data acquisition systems requiring low-power, high-speed sampling.

For engineers reviewing the AD7813YNZ datasheet, AD7813YNZ pinout, AD7813YNZ application, or AD7813YNZ equivalent, key selection considerations include its dual-read 10-bit output format (8 MSBs + 2 LSBs), automatic power-down mode (34.6 µW @ 1 kSPS), 2.3 µs conversion time, and compatibility with 8051/PIC/ADSP-21xx parallel bus protocols.

Technical Context

The AD7813YNZ implements a charge redistribution DAC architecture with internal 1.5 µs power-up timing and precise track/hold acquisition (≤100 ns). Its conversion control relies solely on the CONVST signal, which governs both mode selection (Mode 1 for continuous 400 kSPS operation; Mode 2 for automatic power-down between conversions) and internal gating logic.

It uses straight-binary coding with LSB = VREF/1024, supports analog input range 0 V to VREF (VREF = 1.2 V to VDD), and features TTL-compatible three-state outputs (DB0–DB7) enabled by CS/RD coordination - no external address latching required for 8051 or PIC16C6x interfacing.

Key Specifications

Pinout & Package

The AD7813YNZ is housed in a 16-lead, 0.3" wide plastic DIP (N-16 package), with pins arranged in dual-in-line configuration and standard 0.1" pitch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit SAR ADC applications.

Compared with AD7813YNZ, AD7812BNZ sacrifices 2 bits of resolution while retaining identical packaging and interface simplicity, whereas ADS7822U trades parallel ease-of-use and automatic power control for higher resolution and smaller footprint - making AD7813YNZ optimal for 10-bit, microprocessor-native, low-power DAQ.

Availability

AD7813YNZ is available at Aetrix Electronics and suitable for portable instrumentation, motor control feedback systems, and industrial PLC analog input modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7813YNZ 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 global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The AD7813YNZ belongs to Analog Devices' precision SAR ADC product line, designed specifically for microprocessor-centric data acquisition systems demanding low power, single-supply operation, and seamless parallel bus integration.

FAQ

What is the resolution and effective number of bits (ENOB) of the AD7813YNZ?

The AD7813YNZ is a guaranteed 10-bit ADC with no missing codes. Its dynamic performance yields 58 dB SNR at 30 kHz input, corresponding to an ENOB of approximately 9.3 bits (ENOB = (SNR – 1.76)/6.02). This means the AD7813YNZ delivers usable resolution close to 10 bits in practical AC applications, consistent with its DC relative accuracy of ±1 LSB. The AD7813YNZ maintains this performance across its full industrial temperature range.

How does the AD7813YNZ handle 10-bit data output using an 8-bit bus?

The AD7813YNZ outputs its 10-bit result via two sequential 8-bit reads: the first read places the 8 most significant bits (MSBs) on DB7–DB0, and the second read places the 2 least significant bits (LSBs) on DB7 and DB6 (with DB5–DB0 forced to 0). This dual-read protocol requires no external logic and is synchronized to the BUSY signal's falling edge. The AD7813YNZ automatically resets the interface when BUSY goes high, ensuring deterministic timing for each conversion cycle.

Does the AD7813YNZ require an external clock source?

No, the AD7813YNZ contains a fully integrated clock oscillator and requires no external clock source. All timing - including conversion initiation, track/hold control, and internal logic sequencing - is derived from this on-chip oscillator. This eliminates clock routing complexity, jitter sensitivity, and component count in systems where precise external timing is unavailable or undesirable. The AD7813YNZ's 2.3 µs conversion time is fixed and independent of external clock variation.

What are the power-down modes supported by the AD7813YNZ?

The AD7813YNZ supports automatic power-down (Mode 2), where it powers down at the end of each conversion and powers up before the next one - reducing average power to 34.6 µW at 1 kSPS. It also supports continuous high-speed operation (Mode 1), maintaining full power for 400 kSPS throughput. Mode selection is controlled solely by the logic state of the CONVST pin at BUSY's falling edge: high = Mode 1, low = Mode 2. No register writes or configuration pins are needed.

Can the AD7813YNZ interface directly with an 8051 microcontroller without glue logic?

Yes, the AD7813YNZ interfaces directly with the 8051 using only its native parallel port: BUSY serves as an interrupt request, CS and RD coordinate data reads, and DB0–DB7 connect to Port 0. The AD7813YNZ's three-state outputs and lack of address decoding requirement eliminate the need for external latches or logic gates. Its 2.3 µs conversion time and 100 ns read setup allow tight timing alignment with 8051 machine cycles, and its 3 V–5 V supply compatibility covers standard 8051 voltage domains.