Analog Devices Inc. AD7813YRU

Overview

AD7813YRU from Analog Devices is a 10-bit, 400 kSPS successive approximation ADC with on-chip track-and-hold, single-supply operation (2.7 V–5.5 V), and 8-bit parallel interface for microprocessor/DSP interfacing. It delivers ±1 LSB relative accuracy, 58 dB SNR at 30 kHz input, and automatic power-down mode reducing consumption to 34.6 µW at 1 kSPS - used in portable data acquisition and battery-powered sensor interfaces.

For engineers reviewing the AD7813YRU datasheet, AD7813YRU pinout, AD7813YRU application, or AD7813YRU equivalent, key selection considerations include its dual-read 10-bit output format (MSB/LSB), TSSOP-16 package constraints, 2.3 µs conversion time, and VREF range of 1.2 V to VDD - critical for low-voltage embedded analog front-end design.

Technical Context

The AD7813YRU implements a charge redistribution DAC architecture with internal clock oscillator and three-state TTL-compatible digital outputs. Its conversion process begins on the falling edge of CONVST, with BUSY asserted high during the 2.3 µs conversion window and latched result available for two sequential 8-bit reads.

It supports two operational modes: Mode 1 (high-speed, no inter-conversion power-down) for ≥100 kSPS throughput, and Mode 2 (automatic power-down between conversions) enabling ultra-low average power at reduced sampling rates - controlled solely by external CONVST timing relative to BUSY transition.

Key Specifications

Pinout & Package

AD7813YRU is housed in a 16-lead Thin Shrink Small Outline Package (TSSOP, RU-16), 4.4 mm × 5.0 mm body, 0.65 mm lead pitch, with exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7812YRU and ADS7822U, the AD7813YRU uniquely balances 10-bit precision, parallel microprocessor compatibility, integrated T/H, and automatic power-down - making it optimal for compact, low-power, real-time embedded systems needing deterministic 8-bit bus access without serial protocol overhead.

Availability

AD7813YRU is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor nodes, and medical wearable designs requiring stable component supply, long-term manufacturability, and guaranteed RoHS-compliant sourcing.

Supply support for AD7813YRU 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 AD7813 belongs to Analog Devices' legacy high-speed SAR ADC product line, designed specifically for microprocessor-centric embedded systems demanding low-power, single-supply, parallel-interface analog digitization with guaranteed monotonicity and no missing codes.

FAQ

What is the correct sequence to read a full 10-bit result from the AD7813YRU?

The AD7813YRU requires two consecutive 8-bit reads after BUSY goes low. The first read retrieves the 8 most significant bits (MSBs) on DB7–DB0. The second read retrieves the 2 least significant bits (LSBs) on DB7 and DB6, with DB5–DB0 forced to zero. Both reads must occur while CS and RD are low, and the second read must follow the first by at least 10 ns (t8). This two-phase access is mandatory - no single 10-bit parallel bus is provided.

Does the AD7813YRU require an external clock source?

No, the AD7813YRU does not require an external clock. It contains a fully integrated clock oscillator that drives the successive approximation logic and track-and-hold timing. All timing is controlled via the CONVST input: rising edge initiates internal power-up, and falling edge triggers conversion. External clocking is neither supported nor necessary for standard operation of the AD7813YRU.

Can the AD7813YRU operate with a 2.5 V supply?

Yes, the AD7813YRU is fully specified for operation from 2.7 V to 5.5 V, so 2.5 V is below the minimum rated supply. Operating at 2.5 V violates the Absolute Maximum Ratings and may cause failure to power up, incorrect conversion results, or undefined BUSY/IO behavior. For reliable function, VDD must be ≥2.7 V - confirmed in both DC Accuracy and Power Supply sections of the AD7813YRU datasheet.

How does the automatic power-down mode work in the AD7813YRU?

In automatic power-down mode (Mode 2), the AD7813YRU powers down its analog core immediately after BUSY goes low and remains in low-current state until the next rising edge on CONVST initiates a 1.5 µs internal power-up pulse. This reduces average current to 1 µA standby and enables 34.6 µW operation at 1 kSPS. Mode selection depends solely on CONVST timing relative to BUSY - no register writes or configuration pins are involved in the AD7813YRU.

Is the AD7813YRU pin-compatible with other AD7813 variants like AD7813YR or AD7813YN?

Yes, all AD7813 variants - including AD7813YRU, AD7813YR, and AD7813YN - share identical pin functions and electrical specifications. They differ only in package type (TSSOP, SOIC, DIP) and mechanical dimensions. The pin numbering, signal assignments (e.g., VREF on Pin 1, VDD on Pin 16), and timing behavior are fully consistent across variants, enabling direct PCB footprint substitution where package height and soldering method permit.