Analog Devices Inc. AD7875KRZ

Overview

AD7875KRZ from Analog Devices is a complete monolithic 12-bit sampling analog-to-digital converter (ADC) with integrated track-and-hold amplifier, laser-trimmed internal clock, and on-chip 3 V buried Zener reference. It supports unipolar 0 V to +5 V input range, achieves 100 kHz sampling rate, delivers 72 dB SNR at 10 kHz input, and features 57 ns data access time for microprocessor interfacing.

For engineers reviewing the AD7875KRZ datasheet, AD7875KRZ pinout, AD7875KRZ application, or AD7875KRZ equivalent, this device serves as a high-accuracy, low-power ADC for data acquisition systems requiring stable dc accuracy (±1 LSB INL max), dynamic performance validation, and flexible parallel/byte/serial digital interface support in industrial and embedded signal chain designs.

Technical Context

The AD7875KRZ implements a successive approximation register (SAR) architecture with a dedicated 2 μs track-and-hold amplifier and internal 3 V reference, enabling full-scale conversion of 0 V to +5 V signals without external components. Its laser-trimmed clock ensures guaranteed 8 μs conversion time with ±5% supply tolerance and operates over −40°C to +85°C.

It supports three output formats-12-bit parallel, two 8-bit bytes, or serial-via configurable 12/8/CLK and HBEN pins, and uses standard TTL-compatible control signals (CS, RD, CONVST) for direct interfacing with 8-bit/16-bit microprocessors and DSPs without glue logic.

Key Specifications

Pinout & Package

AD7875KRZ is housed in a 28-pin plastic leaded chip carrier (PLCC) package with 1.27 mm pitch and JEDEC MO-118 compliant outline. Pin functions are electrically validated per Analog Devices Rev. C datasheet Figure 3 and Table 5.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7875KRZ, AD7870KRZ shares pinout and timing but requires input scaling for unipolar sources, while ADS7822U trades parallel flexibility and internal reference for smaller size and lower supply voltage-making AD7875KRZ optimal for industrial 0–5 V acquisition with microprocessor bus integration.

Availability

AD7875KRZ is available at Aetrix Electronics and suitable for industrial data acquisition, test equipment, embedded control systems, and DSP-based signal processing requiring stable component supply across extended temperature ranges.

Supply support for AD7875KRZ 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The AD7875KRZ belongs to the LC2MOS Complete ADC family, designed specifically for industrial and instrumentation applications demanding integrated functionality, guaranteed ac/dc specifications, and robust operation from −40°C to +85°C.

FAQ

What is the input voltage range supported by the AD7875KRZ?

The AD7875KRZ supports a unipolar analog input range of 0 V to +5 V, with typical input resistance of 25 kΩ and full-scale resolution of 1.22 mV per LSB. This range is fixed and not software-configurable; it differs from the ±3 V range of AD7870KRZ and ±10 V range of AD7876KRZ. The AD7875KRZ does not accept negative input voltages or exceed +5 V without external clamping.

Does the AD7875KRZ require an external clock to operate?

No, the AD7875KRZ includes a laser-trimmed internal clock oscillator that guarantees 8 μs conversion time without external timing components. An external 2.5 MHz TTL clock may be applied to the CLK pin for tighter timing control or synchronization, but tying CLK to VSS enables autonomous operation. The internal clock is factory trimmed and specified across the full −40°C to +85°C temperature range.

What digital interface modes does the AD7875KRZ support?

The AD7875KRZ supports three hardware-selectable digital interface modes via the 12/8/CLK pin: 12-bit parallel output (12/8/CLK = +5 V), byte-mode (12/8/CLK = 0 V or −5 V with HBEN control), and serial output using SDATA, SCLK, and SSTRB pins. All modes share common CS, RD, and BUSY/INT signals, enabling flexible integration with microcontrollers, FPGAs, and DSPs without protocol translation.

What is the purpose of the REF OUT pin on the AD7875KRZ?

The REF OUT pin provides the internal 3.00 V ±10 mV buried Zener reference voltage, used internally for DAC and comparator biasing. It can source up to 500 μA for external scaling circuits (e.g., generating 5 V or 10 V references via resistor dividers), but must not be loaded dynamically during conversion. Capacitive loading is limited to 50 pF; for external use, a 200 Ω series resistor plus 10 μF tantalum and 0.1 μF ceramic decoupling is required.

How is conversion initiated on the AD7875KRZ?

Conversion on the AD7875KRZ is initiated asynchronously via the CONVST pin: a rising edge forces the track-and-hold amplifier into hold mode and starts the 8 μs conversion sequence. Alternatively, if CONVST is tied low, a falling edge on CS initiates conversion. Both methods are fully compatible with microprocessor timing and do not require clock synchronization. The BUSY/INT pin transitions low during conversion and returns high upon completion.