Texas Instruments ADS8405IPFBT

Overview

ADS8405IPFBT from Texas Instruments is a 16-bit, 1.25-MSPS unipolar pseudo-differential SAR analog-to-digital converter with integrated 4.096-V reference, parallel interface, and zero-latency operation. It delivers ±1 LSB DNL (max), 86 dB SNR at 100 kHz, and operates from single 5-V analog supply with wide 2.7–5.25-V I/O voltage range. Used in high-resolution data acquisition for medical instruments and communications systems.

For engineers reviewing the ADS8405IPFBT datasheet, ADS8405IPFBT pinout, ADS8405IPFBT application, or ADS8405IPFBT equivalent, this page provides verified technical context, package-validated pin functions, real-world timing constraints, confirmed alternative options, and supply-chain support for industrial embedded and test equipment design.

Technical Context

The ADS8405IPFBT implements a capacitor-based successive approximation register (SAR) architecture with inherent sample-and-hold, enabling true zero-latency conversion. Its internal 4.096-V reference is double-buffered and supports external reference input (2.5–4.2 V) via REFIN/REFM pins.

It features dual-mode parallel output: full 16-bit bus (DB15–DB0) when BYTE = 0, or two 8-bit reads (MSB then LSB folded to DB15–DB8) when BYTE = 1. Timing is controlled entirely by internal oscillator-no external clock required-and conversion completes in 500–650 ns with 150-ns acquisition time.

Key Specifications

Pinout & Package

ADS8405IPFBT is housed in a 48-pin TQFP (PFB) package with exposed thermal pad, rated for –40°C to +85°C industrial operation. Pin assignments are validated per TI SLAS427 datasheet Figure 6 and Terminal Functions table.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed SAR ADC applications.

Compared with ADS8405IPFBT, ADS8401IPFBT trades 1-bit resolution for lower cost and slightly relaxed linearity, while ADS8411IPFBT adds full differential capability at identical speed-neither is pin-compatible, but all three share footprint and control logic, easing redesign.

Availability

ADS8405IPFBT is available at Aetrix Electronics and suitable for medical instrumentation, communications test equipment, high-speed data acquisition systems, and transducer interface applications requiring stable component supply across extended product lifecycles.

Supply support for ADS8405IPFBT 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

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision data converters and industrial-grade IC design.

The ADS8405IPFBT belongs to TI's high-speed SAR ADC family targeting applications demanding zero-latency, high SNR, and flexible parallel interfacing-designed specifically for test & measurement, medical imaging, and communications infrastructure.

FAQ

What is the maximum sampling rate supported by the ADS8405IPFBT?

The ADS8405IPFBT supports a maximum throughput rate of 1.25 MSPS, achieved with a 500–650 ns conversion time and 150 ns acquisition window. This rate is guaranteed across the full industrial temperature range (–40°C to +85°C) and requires proper timing alignment of CONVST, CS, and RD signals per the datasheet's timing diagrams.

Does the ADS8405IPFBT require an external clock source?

No, the ADS8405IPFBT does not require an external clock. It uses an internal oscillator to generate the conversion clock, enabling autonomous operation with only CONVST, CS, and RD control signals needed. This eliminates clock distribution complexity and jitter sensitivity in system-level timing design.

How is the internal 4.096-V reference configured on the ADS8405IPFBT?

To use the internal reference on the ADS8405IPFBT, connect REFOUT (pin 2) to REFIN (pin 1) with a 0.1-µF ceramic capacitor, and place a 1-µF storage capacitor between REFOUT and REFM (pins 47/48). The internal reference is double-buffered and provides 4.096 V ±30 mV with 36 ppm/°C drift over temperature.

Can the ADS8405IPFBT interface directly with a 3.3-V microcontroller?

Yes, the ADS8405IPFBT supports a wide digital I/O supply range of 2.7 V to 5.25 V on +VBD. When powered with +VBD = 3.3 V, its CMOS-compatible outputs (BUSY, RD, CS, DBx) meet 3.3-V logic thresholds, and inputs accept standard 3.3-V levels-no level-shifting circuitry is required.

What is the function of the BYTE pin on the ADS8405IPFBT?

The BYTE pin (pin 39) configures the ADS8405IPFBT's parallel output mode: when LOW, DB15–DB0 deliver the full 16-bit result; when HIGH, DB15–DB8 output the LSB byte (D7–D0) for 8-bit bus compatibility, requiring two sequential reads to retrieve the complete word.