Texas Instruments LM1572MTC-3.3/NOPB

Overview

LM1572MTC-3.3/NOPB from Texas Instruments (formerly National Semiconductor) is a fixed-output 3.3V, 1.5A, 500kHz synchronous step-down DC/DC regulator in TSSOP-16 package. It integrates a 150mΩ MOSFET switch, uses current-mode control for fast transient response, and delivers regulated power from 8.5V–16V input to low-voltage logic rails in LCD monitors and set-top boxes.

For engineers reviewing the LM1572MTC-3.3/NOPB datasheet, LM1572MTC-3.3/NOPB pinout, LM1572MTC-3.3/NOPB application, or LM1572MTC-3.3/NOPB equivalent, key selection factors include guaranteed 1.5A load capability, 26µA shutdown current, programmable soft-start, thermal/short-circuit protection, and fixed 3.3V output with ±3% feedback accuracy over temperature.

Technical Context

The LM1572MTC-3.3/NOPB implements peak-current-mode control with internal slope compensation, enabling stable operation across wide input (8.5–16V) and load conditions. Its 500kHz switching frequency supports compact external components-typically 4.7µH inductor and 22µF ceramic output capacitor-while maintaining >85% efficiency at full load.

It features cycle-by-cycle current limiting, undervoltage lockout (2.38V threshold), TTL-compatible shutdown (1.0V logic high), and fixed 3.3V output set via internal resistor divider with V_FB = 3.3V ±3% (3.22–3.44V). Feedback pin bias current is ≤1.5µA, minimizing divider error.

Key Specifications

Pinout & Package

TSSOP-16 (NS Package Number MTC16), thermally enhanced with exposed pad (not electrically connected), 5mm × 4.4mm footprint, 0.65mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS54331DR and MP2315GJ-Z, the LM1572MTC-3.3/NOPB uniquely combines fixed 3.3V output, programmable soft-start, frequency foldback, and integrated protection in TSSOP-16-making it optimal for cost-sensitive, thermally constrained consumer power rails where design simplicity and reliability are prioritized over raw current headroom or miniaturization.

Availability

LM1572MTC-3.3/NOPB is available at Aetrix Electronics and suitable for LCD monitors, set-top boxes, and cable modems requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for LM1572MTC-3.3/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 acquired National Semiconductor in 2011 and maintains its legacy analog power portfolio with full datasheet, simulation model, and application note support.

The LM1572 series was designed specifically for compact, high-efficiency 12V-to-3.3V/5V conversion in consumer video and broadband equipment, emphasizing thermal robustness, EMI control, and ease of implementation.

FAQ

What is the maximum input voltage rating for LM1572MTC-3.3/NOPB?

The absolute maximum input voltage for LM1572MTC-3.3/NOPB is 17V, but the recommended operating range is 8.5V to 16V per the datasheet's Operating Ratings. Exceeding 16V may trigger undervoltage lockout or reduce reliability; sustained operation above 16V risks damage even if within absolute max limits.

Does LM1572MTC-3.3/NOPB require an external feedback resistor network?

No. The LM1572MTC-3.3/NOPB is a fixed-output variant with internal resistor divider setting V_FB to 3.3V. The FB pin is not accessible for external adjustment-unlike the adjustable LM1572 versions-and no external resistors are needed, simplifying layout and reducing BOM cost.

What thermal derating applies to LM1572MTC-3.3/NOPB at 125°C ambient?

With θ_JA = 130°C/W and T_J(MAX) = 150°C, LM1572MTC-3.3/NOPB supports ~1.5A at 25°C ambient but must be derated to ~0.9A at 125°C ambient to maintain T_J ≤ 150°C. Adequate copper area and airflow are essential for full-load operation at high ambient temperatures.

Can LM1572MTC-3.3/NOPB be used with ceramic output capacitors only?

Yes. LM1572MTC-3.3/NOPB is optimized for low-ESR ceramic output capacitors (e.g., 22µF X5R/X7R). Its current-mode control and internal compensation ensure stability without electrolytic or tantalum capacitors, supporting compact, high-reliability designs in consumer electronics.

Is the shutdown pin of LM1572MTC-3.3/NOPB compatible with 3.3V logic levels?

Yes. The SD pin of LM1572MTC-3.3/NOPB is TTL-compatible with a 1.0V typical enable threshold and 1.28V max logic-high threshold. It interfaces directly with 3.3V GPIO outputs without level-shifting, enabling simple power sequencing in systems with multiple voltage rails.