Analog Devices Inc. AD7819YRZ

Overview

AD7819YRZ from Analog Devices is an 8-bit, 200 kSPS successive approximation ADC with on-chip track-and-hold, 4.5 µs conversion time, and parallel 8-bit TTL-compatible interface. It operates from a single 2.7 V to 5.5 V supply, supports analog input range of 0 V to VREF (1.2 V to VDD), and targets microprocessor- and DSP-based data acquisition systems requiring low power and deterministic timing.

For engineers reviewing the AD7819YRZ datasheet, AD7819YRZ pinout, AD7819YRZ application, or AD7819YRZ equivalent, key selection considerations include its automatic power-down mode (57.75 µW @ 1 kSPS), ±0.5 LSB relative accuracy, 48 dB SNR at 30 kHz input, 100 ns track/hold acquisition time, and compatibility with 8051, PIC16C6x, and ADSP-21xx parallel interfaces.

Technical Context

The AD7819YRZ implements a charge redistribution DAC architecture with internal clock oscillator and three-state output drivers. Its control logic manages dual operating modes: Mode 1 for continuous high-speed sampling (≥100 kSPS) without inter-conversion power-down, and Mode 2 enabling automatic power-down between conversions to reduce average power consumption.

Timing is governed solely by the CONVST signal - a rising edge triggers a 1.5 µs internal power-up pulse, while the falling edge initiates conversion and determines mode selection based on its state at BUSY deassertion. The parallel interface uses CS and RD to enable DB0–DB7 outputs, with BUSY indicating active conversion status.

Key Specifications

Pinout & Package

The AD7819YRZ is housed in a 16-lead narrow-body SOIC package (R-16A), 0.15" wide, with standard JEDEC MS-012AC outline dimensions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 8-bit parallel ADC applications.

Compared with AD7819YRZ, AD7820JN trades speed and integration for cost, while MAX1112CPE+ replaces parallel simplicity with serial compactness - neither offers identical combination of 200 kSPS, on-chip T/H, automatic power-down, and TTL-compatible parallel interface.

Availability

AD7819YRZ is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor interfaces, medical diagnostics, and test equipment requiring stable component supply and guaranteed long-term availability.

Supply support for AD7819YRZ 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, serving precision instrumentation, industrial, communications, and healthcare markets.

The AD7819YRZ belongs to Analog Devices' legacy high-speed parallel ADC product line, designed specifically for microprocessor- and DSP-coupled data acquisition where deterministic timing, low power, and minimal external components are essential.

FAQ

What is the maximum sampling rate supported by the AD7819YRZ?

The AD7819YRZ achieves a maximum throughput rate of 200 kSPS in Mode 1 (continuous high-speed operation). This requires the external CONVST signal to remain high between conversions so the device does not enter power-down. At 200 kSPS, the minimum inter-conversion interval is 5 µs - accounting for 4.5 µs conversion time plus timing margins. In Mode 2 (automatic power-down), sustained rates above ~50 kSPS significantly increase average power consumption due to repeated power-up cycles.

Does the AD7819YRZ require an external clock source?

No, the AD7819YRZ does not require an external clock source. It integrates a precision on-chip oscillator that drives the successive approximation logic and track-and-hold circuitry. All timing is derived from the CONVST signal: a rising edge triggers a 1.5 µs internal power-up pulse, and the falling edge initiates conversion. This eliminates clock routing, jitter concerns, and external component dependencies - simplifying layout and improving system reliability.

How does the AD7819YRZ handle power management in low-throughput applications?

The AD7819YRZ implements automatic power-down (Mode 2) to minimize average power at low throughput. When CONVST is pulled low before BUSY falls, the device powers down immediately after conversion completion. It remains in this 1 µA standby state until the next rising edge on CONVST triggers a 1.5 µs power-up sequence. At 1 kSPS, this yields just 57.75 µW average dissipation at 3 V - making AD7819YRZ suitable for multi-year battery operation in remote sensors and portable meters.

Can the AD7819YRZ interface directly with an 8051 microcontroller?

Yes, the AD7819YRZ interfaces directly with the 8051 microcontroller using its parallel port without address latches or glue logic. BUSY serves as an interrupt request (INT) to signal conversion completion; CS and RD connect to P3.7 (WR) and P3.6 (RD) respectively; DB0–DB7 share Port 0's bidirectional data bus. The 8051's ALE signal is unused since AD7819YRZ requires no address decoding - only simple I/O strobing. This configuration is validated in Analog Devices Application Note AN-283.

What is the analog input voltage range specification for the AD7819YRZ?

The AD7819YRZ analog input (VIN) accepts signals from 0 V to VREF, where VREF is externally applied to Pin 1 and may range from 1.2 V to VDD (2.7 V to 5.5 V). This allows flexible scaling: with VREF = 3.0 V, the input range is 0–3.0 V (11.7 mV/LSB); with VREF = VDD = 5.0 V, it becomes 0–5.0 V (19.5 mV/LSB). Input leakage is ±1 µA max, and the internal sampling capacitor (3.5 pF) requires source impedance ≤2 kΩ to settle within 100 ns for full 8-bit accuracy.