Texas Instruments TPS75618KTTT

Overview

TPS75618KTTT from Texas Instruments is a 5-A, 1.8-V fixed-output low-dropout (LDO) voltage regulator in a TO-263 (KTT) surface-mount package. It delivers up to 5 A with a typical dropout voltage of 250 mV at full load, quiescent current of 125 µA, ±3% output voltage tolerance over line/load/temperature, and integrated thermal shutdown. It serves as a primary post-regulator in high-current FPGA core supplies and DSP power rails.

For engineers reviewing the TPS75618KTTT datasheet, TPS75618KTTT pinout, TPS75618KTTT application, or TPS75618KTTT equivalent, key selection criteria include dropout performance at 5 A, fast transient response under 1.25 A/µs load steps, EN-controlled enable/disable sequencing, thermal derating in TO-263 packages, and compatibility with 47 µF minimum output capacitance.

Technical Context

The TPS75618KTTT uses a PMOS pass element enabling low dropout (250 mV @ 5 A) and load-independent quiescent current (125 µA). Its bandgap reference is trimmed to 1.22 V, supporting ±3% output accuracy across –40°C to +125°C junction temperature.

It integrates overcurrent limiting (~10 A peak), thermal shutdown (150°C trip), undervoltage lockout (UVLO: 2.2–2.75 V), and fast transient recovery (< 200 µs for 5-A step). The FB/NC pin is unconnected for fixed-output variants, simplifying layout versus adjustable versions.

Key Specifications

Pinout & Package

TPS75618KTTT is housed in a 5-pin TO-263 (KTT) thermally enhanced surface-mount package with exposed thermal pad. Pin 1 is EN, Pin 2 is IN, Pin 3 is GND, Pin 4 is OUTPUT, and Pin 5 is FB/NC (no connection for fixed-output version).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with TPS75718KTTR, TPS75618KTTT lacks power-good signaling but offers identical thermal performance and lower cost; compared with LP3879SD-1.8/NOPB, it adds EN functionality and achieves 50 mV lower dropout, enabling tighter input voltage margins.

Availability

TPS75618KTTT is available at Aetrix Electronics and suitable for FPGA core supplies, DSP power rails, medical imaging ASIC biasing, and industrial PLC power distribution requiring stable component supply and long-term production continuity.

Supply support for TPS75618KTTT 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 LDO design expertise and broad automotive/industrial qualification.

The TPS756xx family was engineered for high-current, low-noise post-regulation in FPGA, DSP, and ASIC applications where dropout voltage, transient response, and thermal reliability are critical.

FAQ

What is the minimum input voltage required for TPS75618KTTT to regulate 1.8 V at 5 A?

The minimum input voltage is calculated as VO + VDO(max). For TPS75618KTTT, VDO is 500 mV maximum at 5 A and 125°C, so VI(min) = 1.8 V + 0.5 V = 2.3 V. However, per datasheet recommended conditions, VI must be ≥2.8 V for reliable operation across temperature and load extremes. Always verify with worst-case VDO from Figure 11.

Can TPS75618KTTT be used without an output capacitor?

No. TPS75618KTTT requires a minimum 47 µF output capacitor with ≥200 mΩ ESR for loop stability. Omitting it causes oscillation or catastrophic failure. Ceramic capacitors alone are insufficient due to low ESR; solid tantalum or aluminum electrolytic types meeting the ESR–capacitance product guideline (≥9.4 µV·s) are recommended.

Does TPS75618KTTT have reverse current protection?

TPS75618KTTT does not include active reverse current protection. Its PMOS pass transistor has an intrinsic body diode that conducts from OUTPUT to IN when VIN falls below VOUT (e.g., during power-down). This can back-drive upstream supplies. External reverse-blocking circuitry (e.g., series Schottky diode) is required in systems where reverse current must be prevented.

How does the EN pin behave during power-up sequencing?

The EN pin must rise above 2 V to enable TPS75618KTTT. During start-up, if EN ramps slower than VIN, the device remains disabled until EN crosses the threshold, preventing uncontrolled output rise. Typical start-up time from EN assertion to regulated VOUT is <1 ms (see Figure 17), making it suitable for controlled multi-rail sequencing.

What thermal derating applies to TPS75618KTTT in a standard JEDEC 2S2P board without heatsink?

In a standard JEDEC High-K board (2S2P, 1 oz copper planes), TPS75618KTTT has R_θJA = 38.7°C/W. At 55°C ambient, maximum continuous power dissipation before reaching 125°C junction is (125 − 55)°C ÷ 38.7°C/W ≈ 1.81 W. For 1.8-V output at 5 A, this limits usable input voltage to ≤3.6 V (VI ≤ VO + PDmax/IO = 1.8 + 1.81/5 ≈ 3.6 V).