Analog Devices Inc. AD7880CRZ

Overview

AD7880CRZ from Analog Devices is a 12-bit monolithic successive-approximation ADC operating from a single +5 V supply, featuring 66 kHz throughput rate, 12 µs conversion time, and 3 µs track/hold acquisition. It supports unipolar (0 V to 5 V, 0 V to 10 V) and bipolar (±5 V) input ranges using internal resistor networks, and is used in battery-powered portable instrumentation and real-time DSP systems.

For engineers reviewing the AD7880CRZ datasheet, AD7880CRZ pinout, AD7880CRZ application, or AD7880CRZ equivalent, key selection criteria include its LC2MOS process-based low-power operation (2 mW in power-save mode), fast 57 ns data access time, 70 dB SNR at 1 kHz, and compatibility with microprocessor interfaces including ADSP-2100, TMS320C25, and MC68000.

Technical Context

The AD7880CRZ integrates a charge-balanced comparator that provides inherent track-and-hold functionality, enabling 12-bit acquisition in ≤3 µs. Its SAR architecture uses a 12-bit DAC and high-speed comparator synchronized to an external 2.5 MHz TTL-compatible CLKIN signal with 40/60–60/40 duty cycle tolerance.

Control logic responds asynchronously to CONVST rising edge to initiate conversion and asserts BUSY low during the 12 µs max conversion cycle. Data output is enabled via CS and RD low, with three-state DB0–DB11 outputs compliant to TTL voltage levels (VOH ≥ 4.0 V, VOL ≤ 0.4 V).

Key Specifications

Pinout & Package

AD7880CRZ is housed in a 24-lead small-outline integrated circuit (SOIC) package with 0.3-inch width, RoHS-compliant, and rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-bit SAR ADC applications.

Compared with AD7880CRZ, AD7888ARZ adds channel multiplexing but sacrifices parallel interface speed and on-chip track/hold, while ADS7822U offers higher throughput and integrated reference but lacks bipolar input support and SOIC-24 pin compatibility.

Availability

AD7880CRZ is available at Aetrix Electronics and suitable for portable instrumentation, real-time DSP systems, and industrial control loop monitoring requiring stable component supply across extended temperature ranges.

Supply support for AD7880CRZ 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, founded in 1965 and headquartered in Wilmington, MA.

The AD7880CRZ belongs to Analog Devices' precision data acquisition product line, designed specifically for medium-speed, low-power, single-supply 12-bit conversion in portable and embedded systems where interface simplicity and dynamic performance are critical.

FAQ

What input voltage ranges does the AD7880CRZ support?

The AD7880CRZ supports three hardware-configurable input ranges using VINA and VINB connections: 0 V to VREF (e.g., 0–5 V), 0 V to 2×VREF (e.g., 0–10 V), and ±VREF (e.g., ±5 V). All operate from a single +5 V supply with VREF typically tied to VDD. The internal resistor network enables bipolar operation without external level-shifting circuitry, and each range maintains 12-bit resolution with defined LSB sizes (1.22 mV, 2.44 mV, or 2.44 mV respectively).

How does the AD7880CRZ achieve low power consumption?

The AD7880CRZ achieves low power consumption through its LC2MOS process and dedicated MODE pin control. In normal operation (MODE = VDD), it draws 4–5 mA (20–25 mW). When MODE is pulled to 0 V, it enters power-save mode drawing only 750 µA (2 mW typical), reducing quiescent current by >85%. This feature is especially valuable in battery-powered portable systems where intermittent sampling is used, and the AD7880CRZ retains full functionality with no wake-up delay.

What is the role of the BUSY pin on the AD7880CRZ?

The BUSY pin on the AD7880CRZ is an active-low status output indicating conversion progress. It goes low on the rising edge of CONVST and remains low for the full 12 µs conversion time, then transitions high when the conversion result is latched and ready on DB0–DB11. This signal can be used to generate interrupts (e.g., via inverter to ADSP-2100 IRQ) or polled in software to synchronize data reads, eliminating the need for fixed delay loops and ensuring deterministic timing in real-time systems.

Can the AD7880CRZ interface directly with a microprocessor like the MC68000?

Yes, the AD7880CRZ interfaces directly with the MC68000 using standard control signals: CS drives DTACK to insert wait states, AS and R/W generate RD, and BUSY can trigger interrupts. Its 57 ns data access time, TTL-compatible VOH/VOL levels, and three-state outputs meet MC68000 timing requirements. The AD7880CRZ datasheet provides verified interface schematics (Figure 18) and MOVE.W instruction examples, confirming functional interoperability without glue logic in most configurations.

What dynamic performance specifications are guaranteed for the AD7880CRZ?

The AD7880CRZ guarantees 70 dB minimum SNR, –80 dB typical THD, –80 dB typical peak harmonic/spurious noise, and –80 dB typical second- and third-order IMD - all measured at 1 kHz input with 66 kHz sampling. These values are production-tested across the –40°C to +85°C range and reflect true spectral purity for signal processing applications. The 70 dB SNR corresponds to ~11.7 effective bits, validated via FFT analysis per IEEE Std 1057.