Analog Devices Inc. SMP08FP

Overview

SMP08FP from Analog Devices is an 8-channel multiplexed sample-and-hold amplifier with break-before-make switching, ±3 V to ±10 V analog input range (dual supply) or 0.06 V to 10 V (single supply), 0.01% linearity error, and 3.5 µs typical acquisition time for 0 V to 10 V step at 0.1% accuracy. It enables cost-effective channelized calibration in microprocessor-based test instrumentation.

For engineers reviewing the SMP08FP datasheet, SMP08FP pinout, SMP08FP application, or SMP08FP equivalent, key selection considerations include hold-step error (≤4 mV over temperature), droop rate (2–20 mV/s), capacitive load stability (up to 500 pF), and compatibility with 16-bit DAC interfaces requiring low pedestal error and fast channel settling.

Technical Context

The SMP08FP integrates eight independent sample-and-hold buffers with on-chip address decoding, eliminating external logic. Its internal TTL-regulated supply ensures CMOS/TTL compatibility across ±5 V to ±6 V or +7 V to +15 V supply ranges.

It operates in two modes: sample mode (high slew rate of 3–4 V/µs) and hold mode (low droop rate, <20 mV/s), with channel select/deselect times of 90 ns and 45 ns respectively, and analog crosstalk of –72 dB for 0–10 V steps.

Key Specifications

Pinout & Package

16-pin plastic DIP (N-16 package), 0.300-inch width, through-hole mounting. Thermal resistance θ_JA = 76°C/W (socketed).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD781JRZ and MAX196ACNI+, the SMP08FP uniquely delivers octal hold functionality with internal decoding and sub-4 mV hold-step error in a single 16-pin package-enabling compact, low-glitch calibration architectures without external logic or multiple ICs.

Availability

SMP08FP is available at Aetrix Electronics and suitable for automated test equipment calibration, multi-channel data acquisition systems, and programmable power supply control requiring stable component supply and long-term obsolescence management.

Supply support for SMP08FP 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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The SMP08FP belongs to Analog Devices' precision sample-and-hold amplifier product line, designed specifically for multiplexed calibration, channelized instrumentation, and microprocessor-based analog signal retention applications.

FAQ

What is the maximum recommended capacitive load for SMP08FP outputs?

The SMP08FP is specified to remain stable with capacitive loads up to 500 pF, as confirmed in the Dynamic Performance section of its datasheet. This allows direct driving of ADC inputs, long PCB traces, or cable-connected loads without external compensation networks. Exceeding 500 pF may cause overshoot (>30%) or ringing, degrading hold-mode fidelity. For loads above this value, an external unity-gain buffer is advised. The SMP08FP's internal buffer design eliminates the need for external stabilization under the rated condition.

Does SMP08FP support single-supply operation, and what is the valid input voltage range in that configuration?

Yes, SMP08FP supports single-supply operation with VDD = +12 V and VSS = 0 V (ground). In this mode, the valid analog input and output voltage range is 0.06 V to 10.0 V (with 20 kΩ load) or 0.06 V to 9.5 V (with 10 kΩ load), as specified in the Electrical Characteristics table. Operation below 7 V total supply is discouraged, as parameters including acquisition time and offset degrade. The SMP08FP's internal TTL regulator maintains logic compatibility across the full 7–15 V supply range, making +12 V the most common single-supply choice for optimal performance.

What is the purpose of the INH (Inhibit) pin on SMP08FP, and how should it be used?

The INH pin (Pin 6) is an active-low digital input that disables all eight analog outputs simultaneously, forcing them into a high-impedance state. It is used for system-level synchronization-e.g., halting updates across all channels during critical timing windows or isolating outputs during power-up sequencing. When INH is high, outputs follow the selected channel; when pulled low, outputs disconnect regardless of address inputs. The SMP08FP datasheet specifies INH recovery time as 90 ns, enabling tight timing control. Proper pull-up/pull-down biasing is required for unused INH pins to prevent floating states.

How does SMP08FP achieve break-before-make switching, and why is it important?

The SMP08FP implements break-before-make switching via internal timing control of its analog multiplexer-ensuring the previously selected channel is fully disconnected before the next channel connects. This prevents momentary short-circuits between channels, which could cause transient glitches, cross-talk, or damage in systems with mismatched output impedances. The feature is intrinsic to the SMP08FP's architecture and requires no external components. It is especially critical in calibration systems where multiple held voltages feed independent circuits; the SMP08FP's guaranteed break-before-make behavior eliminates the need for external protection diodes or delay logic.

Can SMP08FP be used with a 16-bit DAC, and what hold-time limitations apply?

Yes, SMP08FP is commonly paired with 16-bit DACs in microprocessor-based systems, as noted in its Applications Information. With a droop rate of 2–20 mV/s, the maximum hold time before voltage drift exceeds 1 LSB depends on full-scale range: for a 10 V FS 16-bit DAC (1 LSB ≈ 153 µV), the SMP08FP requires refresh every ~7.7 ms at worst-case 20 mV/s. This is feasible with standard microcontroller polling or timer interrupts. The SMP08FP's low hold-step error (≤4 mV) and 0.01% linearity ensure the held voltage retains DAC resolution without additional trimming. Its channel select time (90 ns) also supports rapid reconfiguration between DAC updates.