Texas Instruments LM26001MXAX/NOPB

Overview

LM26001MXAX/NOPB from Texas Instruments is a 1.5-A synchronous step-down DC/DC converter with current-mode PWM control, 4.0–38-V input range, adjustable 150–500-kHz switching frequency, and high-efficiency sleep mode (≤40 µA I_q). It integrates an N-channel MOSFET switch, internal bootstrap diode, and power-good flag-designed for automotive telematics and battery-powered systems requiring low standby power.

For engineers reviewing the LM26001MXAX/NOPB datasheet, LM26001MXAX/NOPB pinout, LM26001MXAX/NOPB application, or LM26001MXAX/NOPB equivalent, key selection considerations include its HTSSOP-16 exposed-pad package, cycle-by-cycle current limiting, 1.5% reference accuracy, FPWM disable option, and thermal shutdown at 160°C-critical for robust operation in automotive and industrial environments.

Technical Context

The LM26001MXAX/NOPB employs peak-current-mode control with internal slope compensation, enabling stable regulation across wide line/load variations and simplified loop compensation via the COMP pin. Its adaptive sleep mode activates when FB rises ≥1% above nominal and COMP drops to ~0.6 V, reducing switching activity while maintaining output regulation within ±1% ripple.

Functional modes are managed by dedicated pins: FPWM forces continuous PWM operation (disabling sleep), SYNC enables external clock synchronization (±20% range), and EN provides analog-level shutdown with 120-mV hysteresis. The device includes integrated protection features-cycle-by-cycle current limit (1.85–3.2 A), UVLO (3.6–4.2 V startup), short-circuit foldback (71 kHz min), and thermal shutdown (160°C).

Key Specifications

Pinout & Package

LM26001MXAX/NOPB is housed in a thermally enhanced HTSSOP-16 package (5.00 mm × 4.40 mm) with exposed pad (EP) soldered to PCB ground for optimal thermal performance. Pin 1 is VIN (top-left corner, marked dot), and the EP must be electrically connected to GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM26001MXAX/NOPB, LM26002QMHX/NOPB offers higher current capacity in identical packaging, while TPS54302DDAR trades integration for lower sleep current and greater flexibility-making LM26001MXAX/NOPB optimal for cost-sensitive, space-constrained automotive applications requiring proven 1.5-A performance.

Availability

LM26001MXAX/NOPB is available at Aetrix Electronics and suitable for automotive telematics, navigation systems, and battery-powered applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant alternatives.

Supply support for LM26001MXAX/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 leader specializing in analog, embedded processing, and power management technologies-with decades of automotive-grade product validation and manufacturing excellence.

The LM26001MXAX/NOPB belongs to TI's high-voltage buck regulator product line, engineered specifically for automotive and industrial applications demanding wide input range, low quiescent current, and robust protection features in compact packages.

FAQ

What is the minimum input voltage required for continuous operation of the LM26001MXAX/NOPB?

The LM26001MXAX/NOPB requires a minimum 4.0-V input for continuous operation within specification. Although it can tolerate down to 3.0 V during transients (e.g., automotive cold-crank), sustained operation below 4.0 V increases power dissipation due to higher R_DS(on), potentially triggering thermal shutdown. Startup requires ≥3.9 V typical at the VIN pin.

How does the sleep mode of the LM26001MXAX/NOPB function, and what triggers exit from it?

Sleep mode in the LM26001MXAX/NOPB activates automatically when load current drops sufficiently to raise FB ≥1% above nominal and COMP falls to ~0.6 V. Switching halts, reducing I_q to <40 µA. Exit occurs when FB falls to the wake threshold (99% of nominal), causing immediate resumption of PWM regulation-ensuring output ripple remains within ±1%.

Can the LM26001MXAX/NOPB be synchronized to an external clock, and what is the acceptable frequency range?

Yes, the LM26001MXAX/NOPB supports synchronization via the SYNC pin. It accepts external TTL/CMOS clocks and locks to frequencies within ±20% of its nominal switching frequency (e.g., 330 kHz ±66 kHz). For non-synchronized operation, SYNC must be pulled low. The device also supports free-running operation from 150–500 kHz using the FREQ resistor.

What is the purpose of the VBIAS pin on the LM26001MXAX/NOPB, and how should it be configured?

The VBIAS pin on the LM26001MXAX/NOPB accepts an external ≥3-V supply to power internal circuitry, bypassing the internal VDD LDO. This improves efficiency-especially at light loads-and reduces self-heating. If unused, VBIAS must be tied to GND. When connected, it sources up to 0.7 mA bias current and enables lower I_q in sleep mode (~38 µA vs 75 µA).

Does the LM26001MXAX/NOPB include overvoltage or short-circuit protection, and how does it respond?

The LM26001MXAX/NOPB includes short-circuit foldback protection: if FB falls below 0.87 V, switching frequency reduces to as low as 71 kHz to limit average switch current. It does not provide output overvoltage protection-regulation relies on feedback loop integrity. Additional safeguards include cycle-by-cycle current limiting (1.85–3.2 A), thermal shutdown (160°C), and input UVLO (2.6–3.2 V shutdown, 3.6–4.2 V startup).