Analog Devices Inc. SMP18FPZ

Overview

SMP18FPZ from Analog Devices is an octal sample-and-hold IC with multiplexed input, internal hold capacitors, TTL/CMOS-compatible logic inputs, and break-before-make channel addressing. It delivers 0.01% linearity error, 2.5 µs acquisition time (0–10 V to 0.1%), and ±10 V output swing in dual-supply mode. It is used in multichannel data acquisition systems for timing deskew and calibration voltage storage.

For engineers reviewing the SMP18FPZ datasheet, SMP18FPZ pinout, SMP18FPZ application, or SMP18FPZ equivalent, this page provides verified functional context, real-world design meaning of key specs, validated alternative options, and supply-chain support for industrial embedded and test equipment designs.

Technical Context

The SMP18FPZ integrates eight buffer amplifiers, a 1-of-8 decoder, and internal hold capacitors in oxide-isolated CMOS. Its analog signal path supports single-supply (VDD = +12 V, VSS = 0 V) or dual-supply (±5 V to ±6 V) operation, with output compliance from (VSS + 0.06 V) to (VDD – 2 V).

Control logic uses three address bits (A, B, C) and INH for channel selection and global inhibit. All digital inputs meet TTL/CMOS thresholds (VINH ≥ 2.4 V, VINL ≤ 0.8 V), and the device features internally regulated logic supply to maintain compatibility across supply ranges.

Key Specifications

Pinout & Package

The SMP18FPZ is housed in a 16-pin plastic DIP (N-16 package), with through-hole mounting and 0.300-inch body width. Pin 1 is marked by a notch or dot; pins are numbered counterclockwise from top-left corner when viewed from top.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal sample-and-hold applications.

Compared with AD7874KNZ and MAX196BCNI+, the SMP18FPZ offers lower power (7.5 mA), smaller footprint (16-pin DIP), and true independent hold functionality-making it the most efficient solution for analog voltage storage in calibration and control systems.

Availability

SMP18FPZ is available at Aetrix Electronics and suitable for multichannel data acquisition systems, automated test equipment, and industrial process controllers requiring stable component supply across long production lifecycles.

Supply support for SMP18FPZ 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.

The SMP18FPZ belongs to Analog Devices' precision sample-and-hold product line, engineered specifically for calibration-intensive applications in test instrumentation and industrial control where low droop, high linearity, and channel density are critical.

FAQ

What is the maximum recommended supply voltage for SMP18FPZ?

The absolute maximum rating for VDD to DGND is 17 V, but the SMP18FPZ is specified for reliable operation between 7 V and 15 V. Operating above 15 V risks exceeding internal junction temperature limits and degrading long-term reliability. For SMP18FPZ, Analog Devices recommends staying within the 12 V nominal single-supply condition documented in the electrical characteristics tables to ensure guaranteed performance across –40°C to +85°C.

Does SMP18FPZ support true dual-supply operation with negative output swing?

Yes, SMP18FPZ supports true dual-supply operation: with VDD = +5 V and VSS = –5 V, its output voltage range extends from –3.0 V to +3.0 V, including the negative rail. This capability is explicitly confirmed in the GENERAL DESCRIPTION and ELECTRICAL CHARACTERISTICS sections, enabling bipolar signal handling in applications like robotics and medical instrumentation without external level-shifting circuitry.

Can SMP18FPZ be used with a microcontroller's GPIO pins directly?

Yes, SMP18FPZ can interface directly with standard microcontroller GPIO pins because its logic inputs (A, B, C, INH) are TTL/CMOS compatible-requiring only VINH ≥ 2.4 V and VINL ≤ 0.8 V. No level-shifting or buffering is needed, as confirmed in the LOGIC CHARACTERISTICS table and APPLICATIONS INFORMATION section, making SMP18FPZ ideal for compact embedded calibration subsystems.

What is the role of the DGND pin in SMP18FPZ layout?

The DGND pin (pins 7 and 16) serves as the digital ground reference for internal logic and decoder circuitry. Per the APPLICATIONS INFORMATION, DGND traces must be physically separated from analog ground (VSS) on the PCB to prevent digital switching noise from coupling into the analog outputs. Improper grounding violates the noise isolation requirement and directly degrades SMP18FPZ's 0.01% linearity and –72 dB crosstalk performance.

How often must SMP18FPZ outputs be refreshed to maintain 10-bit accuracy?

For a 10-bit system with 10 V full scale (1 LSB = ~9.8 mV), SMP18FPZ's max droop rate of 40 mV/s limits hold time to ≤245 ms before drifting beyond ±1/2 LSB. However, the TYPICAL APPLICATIONS section specifies a conservative 60 ms refresh interval for 10-bit accuracy-based on worst-case droop and load conditions. This value is derived directly from the 40 mV/s max droop and 10 V/1024 = 9.77 mV LSB calculation, ensuring robust margin in production systems.