Analog Devices Inc. AD7875TQ

Overview

AD7875TQ from Analog Devices is a complete monolithic 12-bit sampling ADC with integrated track-and-hold amplifier (2 μs acquisition), laser-trimmed internal clock, on-chip 3 V buried Zener reference, and parallel/byte/serial digital interface. It supports unipolar 0 V to +5 V analog input range, delivers 70 dB SNR at 10 kHz, and achieves 57 ns data access time for microprocessor interfacing in industrial data acquisition systems.

For engineers reviewing the AD7875TQ datasheet, AD7875TQ pinout, AD7875TQ application, or AD7875TQ equivalent, this page provides verified technical context, validated pin functions, confirmed dynamic and dc specifications, real-world application roles, and two rigorously cross-checked alternative parts - all specific to the AD7875TQ variant with −55°C to +125°C extended temperature rating and 24-pin DIP package.

Technical Context

The AD7875TQ implements a successive approximation register (SAR) architecture with a voltage-output DAC and high-speed comparator. Its track-and-hold amplifier operates transparently, transitioning to hold mode on CONVST rising edge or CS falling edge, enabling accurate digitization of full-power signals up to 50 kHz.

It features a self-contained 2.5 MHz internal clock (laser-trimmed, ±0.5% typical accuracy), eliminating external timing components; conversion time is 6.5 μs min / 9 μs max using internal clock. The 3 V reference (±10 mV initial tolerance, ±60 ppm/°C tempco) powers both DAC and bias circuitry and supplies up to 500 μA to external loads.

Key Specifications

Pinout & Package

AD7875TQ is housed in a 24-pin, 0.3 inch-wide hermetic dual-in-line package (DIP) with center-bay configuration. Pin 1 identifier is a circular indentation; pins are numbered counter-clockwise from top-left corner when viewed from top.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD7870TQ and AD7876TQ, the AD7875TQ uniquely supports native 0 V to +5 V unipolar input without scaling or offset adjustment, making it the only drop-in solution for direct interfacing with microcontroller-compatible analog sensors and DACs in extended-temperature embedded systems.

Availability

AD7875TQ is available at Aetrix Electronics and suitable for industrial process monitoring, aerospace sensor interface, downhole oilfield instrumentation, and military data acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AD7875TQ 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, with design and manufacturing facilities worldwide.

The AD7875TQ belongs to the LC2MOS Complete Sampling ADC product line, engineered specifically for high-reliability, extended-temperature data acquisition in aerospace, defense, and industrial control applications where precision, stability, and hermetic packaging are mandatory.

FAQ

What is the analog input voltage range supported by the AD7875TQ?

The AD7875TQ supports a unipolar analog input range of 0 V to +5 V. This is distinct from the AD7870TQ (±3 V) and AD7876TQ (±10 V). The input presents a typical 25 kΩ resistance and produces straight-binary output codes, with 1 LSB equaling 1.22 mV (5 V / 4096). No external level-shifting circuitry is required for standard 0–5 V sensor outputs when using the AD7875TQ.

Does the AD7875TQ require an external clock to operate?

No, the AD7875TQ does not require an external clock. It integrates a laser-trimmed internal oscillator that delivers guaranteed 6.5 μs minimum / 9 μs maximum conversion time. To enable the internal clock, tie the CLK pin (Pin 3) to VSS (−5 V). An external 2.5 MHz TTL clock may be applied instead if tighter timing control or synchronization with other system clocks is needed.

What package type and temperature grade does the AD7875TQ use?

The AD7875TQ is supplied in a 24-pin, 0.3 inch-wide hermetic dual-in-line package (DIP) with center-bay pin layout. It is qualified for the extended temperature range of −55°C to +125°C, denoted by the "T" suffix. This hermetic construction ensures long-term reliability in high-humidity, high-vibration, and thermally aggressive environments such as downhole tools and avionics systems.

How does the AD7875TQ handle reference voltage requirements?

The AD7875TQ includes an on-chip 3 V buried Zener reference trimmed to ±10 mV at +25°C, with ±60 ppm/°C tempco over temperature. REF OUT (Pin 19) supplies up to 500 μA and must be loaded with ≤50 pF capacitance. For applications needing 5 V or 10 V references, Figure 7 in the datasheet shows resistor-divider scaling using the internal 3 V source - but the AD7875TQ itself operates exclusively from its internal 3 V reference.

Can the AD7875TQ interface directly with an 8-bit microprocessor bus?

Yes, the AD7875TQ supports byte-mode interfacing via its HBEN (Pin 4) and 12/8/CLK (Pin 22) controls. When 12/8/CLK is low and HBEN is toggled, the device outputs upper and lower bytes sequentially on DB7–DB0. This allows direct connection to 8-bit data buses without external latches or glue logic, and the 57 ns access time ensures compatibility with common 8051, Z80, and 68000-family processors.