Texas Instruments TLV1117-25CDCY

Overview

TLV1117-25CDCY from Texas Instruments is a fixed-output, 2.5V, 800mA low-dropout linear voltage regulator in a 4-pin SOT-223 (DCY) package. It operates from 3.9V to 15V input, delivers ±1.0% output accuracy at 25°C, features 0.8V typical dropout at 800mA (new chip), and integrates foldback current limit, thermal shutdown, UVLO, and internal soft-start for inrush control - used in industrial power rails and embedded microcontroller supply domains.

For engineers reviewing the TLV1117-25CDCY datasheet, TLV1117-25CDCY pinout, TLV1117-25CDCY application, or TLV1117-25CDCY equivalent, key selection criteria include verified 2.5V output stability under 800mA load, DCY-package thermal resistance (R_θJA = 95.4°C/W), dropout behavior across temperature, and compatibility with 10µF minimum output capacitance for transient response.

Technical Context

The TLV1117-25CDCY implements a CMOS-based LDO architecture with an internal 1.25V bandgap reference and error amplifier driving a P-channel pass transistor. Its fixed 2.5V output is achieved via precision resistor trimming during wafer test, eliminating external feedback components.

This variant belongs to the "new chip" family and includes integrated protection functions: undervoltage lockout (UVLO rising threshold 2.2–2.4V), thermal shutdown (trip at 180°C, reset at 160°C), foldback current limiting (ICL = 1.1–1.6A, ISC = 150–350mA), and output pulldown (0.7–1.1mA) for controlled discharge during disable.

Key Specifications

Pinout & Package

TLV1117-25CDCY uses a 4-pin SOT-223 (DCY) package with exposed thermal pad on bottom; pin 1 is ADJ/GND, pin 2 is OUTPUT, pin 3 is INPUT, and pin 4 is OUTPUT (dual-output configuration for enhanced current handling and thermal path).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output LDO applications.

Compared with TLV1117-25IDCYR, the TLV1117-25CDCY offers tighter room-temperature accuracy but narrower temperature qualification; versus TPS7A4700RGWR, it trades noise performance for integration, simplicity, and cost - making TLV1117-25CDCY optimal for cost-sensitive industrial and consumer power rails where 60µV_RMS noise and built-in protections are sufficient.

Availability

TLV1117-25CDCY is available at Aetrix Electronics and suitable for industrial motor control, smart metering, HVAC systems, and home theater audio requiring stable component supply, long-lifecycle support, and traceable sourcing.

Supply support for TLV1117-25CDCY 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, embedded processing, and power management ICs, with decades of expertise in high-reliability linear regulators and industrial-grade power solutions.

The TLV1117 product line targets cost-optimized, robust power delivery for industrial automation, energy infrastructure, and consumer electronics - emphasizing integration, thermal resilience, and ease of use in space-constrained designs.

FAQ

What is the minimum input voltage required for TLV1117-25CDCY to maintain 2.5V regulation?

The TLV1117-25CDCY requires a minimum input voltage of 3.9V to sustain 2.5V output at full 800mA load, per Recommended Operating Conditions. At lighter loads, the dropout voltage decreases - e.g., 0.4V typical at 100mA - allowing operation as low as ~2.9V input while maintaining regulation. This behavior is confirmed in Section 5.3 and Figure 5-29 of the datasheet.

Does TLV1117-25CDCY require an external capacitor on the ADJ pin?

No - the TLV1117-25CDCY is a fixed-output variant, so the ADJ pin is internally connected to ground and does not require any external components. Pin 1 (ADJ/GND) must be directly tied to system ground with low-impedance routing. External capacitors are only required on INPUT (≥10µF) and OUTPUT (≥10µF tantalum or low-ESR ceramic) per Section 7.3.

How does the foldback current limit function in TLV1117-25CDCY during a short-circuit event?

In a short-circuit condition, the TLV1117-25CDCY limits output current to 150–350mA (ISC), significantly lower than its 1.1–1.6A brick-wall limit (ICL). As V_OUT collapses below 1.25V (50% of nominal 2.5V), the foldback mechanism reduces current proportionally to minimize power dissipation and prevent thermal runaway - detailed in Section 6.3.2 and Figure 6-4.

Can TLV1117-25CDCY be used without a heatsink in a 4-layer PCB?

Yes - with ≥1.5 cm² of 2-oz copper connected to the exposed thermal pad on the DCY package, the TLV1117-25CDCY sustains 800mA at 70°C ambient without external heatsink. Its R_θJA = 95.4°C/W assumes standard JEDEC test board; actual thermal performance improves with additional copper area and internal plane layers, as validated in TI's PCB Thermal Calculator.

What is the purpose of the output pulldown feature in TLV1117-25CDCY?

The output pulldown (0.7–1.1mA) actively discharges the V_OUT node when the device is disabled or input falls below UVLO threshold. This prevents floating outputs that could cause undefined logic states in downstream FPGAs or microcontrollers - a critical requirement in systems with battery backup or hot-swap capability, as specified in Section 5.6.