Texas Instruments LM3102TLX-1/NOPB

Overview

LM3102TLX-1/NOPB from Texas Instruments is a synchronous step-down DC-DC voltage regulator with integrated dual N-channel MOSFETs, 4.5 V to 42 V input range, 2.5-A continuous output current capability, 0.8 V ±1.5% internal reference, and thermally enhanced HTSSOP-20 package. It delivers regulated power in industrial control systems requiring high efficiency across wide input voltages.

For engineers reviewing the LM3102TLX-1/NOPB datasheet, LM3102TLX-1/NOPB pinout, LM3102TLX-1/NOPB application, or LM3102TLX-1/NOPB equivalent, key selection criteria include valley current limit (1.5 A for this variant), COT control architecture, programmable switching frequency up to 1 MHz, soft-start programmability, and thermal shutdown at 165°C.

Technical Context

The LM3102TLX-1/NOPB implements Constant ON-Time (COT) regulation using an internal 0.8-V reference and comparator-driven one-shot timer, eliminating need for external loop compensation. Its valley current limit is fixed at 1.5 A - distinct from the standard LM3102's 2.7 A - and is enforced during synchronous MOSFET off-time via re-circulating current sensing.

It integrates a self-biased start-up regulator (VCC = 6 V, 65 mA current limit), bootstrap gate drive for the high-side N-MOSFET, zero-coil-current detection for DCM operation, and overvoltage protection triggered at 0.92 V on the FB pin. Operating frequency varies inversely with VIN due to fixed ON-time scaling, enabling stable operation across 4.5–42 V input.

Key Specifications

Pinout & Package

LM3102TLX-1/NOPB is housed in a thermally enhanced HTSSOP-20 (PWP) package (6.50 mm × 4.40 mm) with exposed thermal pad (EP). The package supports high-power dissipation in compact industrial and automotive layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3102/NOPB, LM3102TLX-1/NOPB trades peak current capability (1.5 A vs. 2.7 A) for tighter current-limit consistency in cost-sensitive applications; versus TPS54240DGQ, it offers lower system-level component count and faster transient response but less control-loop tunability.

Availability

LM3102TLX-1/NOPB is available at Aetrix Electronics and suitable for industrial control, automotive body electronics, and embedded networking applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for LM3102TLX-1/NOPB 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 specializing in analog, embedded processing, and power management ICs, with decades of leadership in high-reliability DC-DC conversion solutions.

The LM3102 product line delivers highly integrated synchronous buck regulators targeting space-constrained, wide-input-voltage applications in industrial, automotive, and communications infrastructure where efficiency, thermal performance, and design simplicity are critical.

FAQ

What is the valley current limit specification for LM3102TLX-1/NOPB?

The LM3102TLX-1/NOPB has a valley current limit of 1.5 A, as explicitly specified in the Electrical Characteristics table of the SNVS515I datasheet. This value is distinct from the standard LM3102's 2.7-A limit and applies specifically to this variant. The current limit is enforced during the synchronous MOSFET off-time by monitoring re-circulating inductor current. During overload, the LM3102TLX-1/NOPB enters constant-current mode with average output current approximately equal to 1.5 A plus half the inductor ripple current.

Does LM3102TLX-1/NOPB require external loop compensation?

No, LM3102TLX-1/NOPB does not require external loop compensation. It uses a Constant ON-Time (COT) control architecture with an internal comparator and one-shot timer, which inherently provides stability without compensation networks. This simplifies design, reduces component count, and ensures ultra-fast transient response. The regulator remains stable with ceramic output capacitors having very low ESR - a key differentiator from traditional voltage-mode or current-mode controllers that depend on capacitor ESR for phase margin.

What package type and thermal characteristics apply to LM3102TLX-1/NOPB?

LM3102TLX-1/NOPB is packaged in the HTSSOP-20 (PWP) thermally enhanced package measuring 6.50 mm × 4.40 mm with an exposed thermal pad. Its junction-to-ambient thermal resistance (RθJA) is 30°C/W under standard JEDEC test conditions. The exposed pad must be soldered to a PCB thermal plane for optimal heat dissipation. At 100°C ambient, the device sustains 2.5-A output with ≥40 cm² of 2-oz copper; output current derates linearly above that temperature per the published thermal derating curve.

How is switching frequency programmed on LM3102TLX-1/NOPB?

Switching frequency on LM3102TLX-1/NOPB is programmed via an external resistor (RON) connected between the RON pin and AGND. The ON-time varies inversely with input voltage (VIN), resulting in nearly constant frequency across line variations. The maximum achievable frequency is governed by the minimum ON-time of 150 ns and is approximated by fSW(MAX) = VOUT / (VIN(MAX) × 150 ns). For example, with VIN = 42 V and VOUT = 3.3 V, RON must be selected to ensure ton ≥ 150 ns - typically achieved with RON ≈ 100 kΩ yielding ~1 MHz operation.

What protection features are integrated into LM3102TLX-1/NOPB?

LM3102TLX-1/NOPB integrates five key protection features: (1) Output overvoltage protection (OVP) triggered at 0.92 V on the FB pin, (2) Thermal shutdown at 165°C with 20°C hysteresis, (3) VCC undervoltage lockout (UVLO) at 3.75 V, (4) Gate drive UVLO at 3.3 V (BST–SW), and (5) Valley current limiting at 1.5 A. All protections are hardware-based and operate independently of external components. OVP immediately terminates ON-time and discharges the inductor via the synchronous FET; thermal shutdown grounds the SS pin and disables the main MOSFET until junction temperature falls to ~145°C.