Texas Instruments TLC1551IFN

Overview

TLC1551IFN from Texas Instruments is a 10-bit, switched-capacitor successive-approximation analog-to-digital converter (ADC) with parallel DSP/µP interface, 6 µs conversion time, ±1 LSB total unadjusted error, and dual digital supply rails (DGTL VDD1/DGTL VDD2) for noise isolation - used in real-time industrial data acquisition systems requiring high-speed sampling and ratiometric reference accuracy.

For engineers reviewing the TLC1551IFN datasheet, TLC1551IFN pinout, TLC1551IFN application, or TLC1551IFN equivalent, key selection criteria include its 6 µs conversion time, separate analog/digital ground and supply domains, internal/external clock flexibility, 10-bit parallel output (D0–D9), and −40°C to 85°C industrial temperature rating in PLCC-28 package.

Technical Context

The TLC1551IFN implements a switched-capacitor SAR architecture with integrated sample-and-hold, using Advanced LinEPIC™ single-poly CMOS process to achieve close capacitor matching for improved linearity. Its control logic synchronizes conversion initiation on WR rising edge and data latching on EOC falling edge.

It supports both internal clock (derived from divided system clock) and external CLKIN up to 7.8 MHz, with automatic clock detection. The dual digital supply (VDD1 for logic, VDD2 for bus drivers) and split digital grounds (DGTL GND1/GND2) minimize switching noise coupling into analog circuitry during high-current data bus transitions.

Key Specifications

Pinout & Package

Package: PLCC-28 (FN), 4.57 mm max height, lead finish NIPDAU, moisture sensitivity level 1 (260°C reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 10-bit parallel ADC applications.

Compared with ADS7822U and TLC1543CN, the TLC1551IFN delivers deterministic 6 µs latency, hardware handshaking via EOC/RD/WR, and analog noise resilience through physical supply/ground separation - making it uniquely suitable for µP- or DSP-based closed-loop industrial control where timing predictability and measurement integrity are critical.

Availability

TLC1551IFN is available at Aetrix Electronics and suitable for industrial motor control, PLC analog I/O modules, energy metering subsystems, and test equipment requiring stable component supply across extended product lifecycles.

Supply support for TLC1551IFN 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 company headquartered in Dallas, Texas, specializing in analog, embedded processing, and silicon innovation for industrial, automotive, and communications markets.

The TLC155x family was designed specifically for high-speed, noise-immune data acquisition in industrial control systems - emphasizing parallel µP/DSP compatibility, supply-domain isolation, and guaranteed 10-bit accuracy without calibration.

FAQ

What is the maximum recommended external clock frequency for the TLC1551IFN?

The TLC1551IFN supports an external clock input (CLKIN) up to 7.8 MHz, as specified in the recommended operating conditions. Operation above this frequency may cause timing violations or incomplete conversions. At 7.8 MHz, the device maintains its guaranteed 6 µs conversion time and ±1 LSB total unadjusted error across the full −40°C to +85°C temperature range. The TLC1551IFN datasheet confirms this limit under "Input clock frequency, f(CLKIN)" with MAX = 7.8 MHz.

Does the TLC1551IFN require external calibration to achieve its ±1 LSB total unadjusted error specification?

No, the TLC1551IFN achieves ±1 LSB total unadjusted error without external calibration. This specification is guaranteed over temperature and supply voltage variations per the datasheet's electrical characteristics table. The Advanced LinEPIC™ process and matched capacitor array ensure inherent linearity, eliminating the need for user-performed offset/gain trimming. The TLC1551IFN's error budget includes zero-scale, full-scale, and linearity contributions - all covered within the ±1 LSB bound under recommended operating conditions.

Can the TLC1551IFN operate with a single 5-V supply instead of three separate supplies?

No, the TLC1551IFN requires three distinct supply connections: ANLG VDD (for analog circuitry), DGTL VDD1 (for logic), and DGTL VDD2 (for bus drivers). While all three may be tied to the same 5-V rail in low-noise lab environments, the datasheet mandates separate routing and decoupling to maintain ±1 LSB accuracy. Combining DGTL VDD1 and DGTL VDD2 defeats the noise-isolation purpose of the dual-digital-supply architecture and risks violating the total unadjusted error spec in electrically noisy industrial applications.

What is the function of the EOC pin on the TLC1551IFN, and how is it used in a typical µP interface?

The EOC (End-of-Conversion) pin on the TLC1551IFN is an active-low open-drain output that goes low when conversion completes and data is latched into the output register. In a typical µP interface, EOC connects to an interrupt input (e.g., INT0 on 8051) to trigger immediate data read, or is polled before asserting RD to avoid reading stale values. The TLC1551IFN datasheet specifies td(EOC) ≤15 ns (RD low to EOC high), ensuring tight timing control. After RD goes low, EOC resets high automatically - a behavior unique to the TLC1551IFN among its family.

Is the TLC1551IFN pin-compatible with the TLC1550IFN, and what is the key functional difference between them?

Yes, the TLC1551IFN is pin-compatible with the TLC1550IFN in the PLCC-28 (FN) package, sharing identical pinout, supply requirements, and interface timing. The key functional difference is total unadjusted error: TLC1550IFN guarantees ±0.5 LSB max (at 25°C) and ±1 LSB max (full temperature range), while TLC1551IFN guarantees ±1 LSB max across the entire −40°C to +85°C range - making TLC1551IFN the preferred choice for industrial applications requiring consistent accuracy without derating.