Texas Instruments LM26420Q0XMH/NOPB

Overview

LM26420Q0XMH/NOPB from Texas Instruments is a dual-channel synchronous buck DC/DC converter delivering 2 A per channel at 2.5 V and 1.2 V output, operating from 3 V to 5.5 V input, with 2.2 MHz switching frequency and integrated 75-mΩ PMOS / 50-mΩ NMOS power switches - used for core and I/O voltage regulation in FPGAs and ASICs.

For engineers reviewing the LM26420Q0XMH/NOPB datasheet, LM26420Q0XMH/NOPB pinout, LM26420Q0XMH/NOPB application, or LM26420Q0XMH/NOPB equivalent, key selection considerations include independent enable/power-good signaling, 180° phase interleaving for reduced input ripple, internal compensation, prebias start-up capability, and CISPR25 Class 5 EMI compliance.

Technical Context

The LM26420Q0XMH/NOPB implements current-mode PWM control with internal compensation, supporting fixed 2.2 MHz operation (X-version) and enabling stable regulation across 0.8 V–4.5 V output range. Its dual-channel architecture features independent feedback (FB1/FB2), enable (EN1/EN2), and open-drain power-good (PG1/PG2) pins.

Each channel integrates a 75-mΩ PMOS high-side switch and 50-mΩ NMOS low-side switch in BICMOS process, achieving up to 93% efficiency. Channels operate 180° out of phase to minimize input capacitor RMS current and reduce conducted EMI - validated per CISPR25 Class 5 standards.

Key Specifications

Pinout & Package

LM26420Q0XMH/NOPB is packaged in a thermally enhanced HTSSOP-20 (6.50 mm × 4.40 mm) with exposed die attach pad (DAP) connected to system ground for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS54290RGER and MP2491DS-LF-Z, the LM26420Q0XMH/NOPB uniquely delivers independent enable/power-good per channel, 180° phase interleaving, prebias start-up, and CISPR25 Class 5 compliance - making it the only option suitable for automotive-qualified USB devices and FPGA power systems requiring robust sequencing and EMI control.

Availability

LM26420Q0XMH/NOPB is available at Aetrix Electronics and suitable for FPGA power delivery, USB-powered storage devices, HDD electronics, and ASIC core/I/O regulation requiring stable component supply and long-term industrial availability.

Supply support for LM26420Q0XMH/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 ICs, with decades of expertise in high-efficiency DC/DC conversion.

The LM26420 product line was designed specifically for space-constrained, high-density power systems in computing, storage, and automotive infotainment - emphasizing low EMI, precise sequencing, and seamless integration with digital loads.

FAQ

What input voltage range does the LM26420Q0XMH/NOPB support?

The LM26420Q0XMH/NOPB supports an input voltage range of 3 V to 5.5 V. This range allows direct operation from standard USB 5 V sources, 3.3 V–5 V intermediate rails, or battery-backed systems. The device incorporates undervoltage lockout (UVLO) that activates at 2.63 V (rising) and releases at 2.3 V (falling), ensuring reliable startup and shutdown behavior across its specified input range. Operation outside this range may damage the LM26420Q0XMH/NOPB or cause malfunction.

Does the LM26420Q0XMH/NOPB support independent enable and power-good signaling per channel?

Yes, the LM26420Q0XMH/NOPB provides fully independent EN1/EN2 enable inputs and PG1/PG2 open-drain power-good outputs for each buck channel. Each EN pin has a precision 1.04 V threshold with 150 mV hysteresis, and each PG pin asserts low when its respective output is within ±7.5% of the programmed voltage. This enables flexible power sequencing, fault isolation, and system-level monitoring - critical for FPGA, ASIC, and multi-rail embedded designs where timing and rail health must be controlled separately.

What is the switching frequency of the LM26420Q0XMH/NOPB and why does it matter?

The LM26420Q0XMH/NOPB operates at a fixed 2.2 MHz switching frequency (X-version). This high frequency allows the use of small, low-profile inductors (typically 1–2.2 µH) and compact ceramic output capacitors (10–22 µF), significantly reducing solution footprint and enabling placement in tight spaces such as portable SSD enclosures or dense FPGA carrier boards. It also supports effective input ripple cancellation through 180° phase interleaving between channels - a key advantage over lower-frequency alternatives like the 550 kHz Y-version or competing 500 kHz regulators.

Can the LM26420Q0XMH/NOPB start up into a prebiased output?

Yes, the LM26420Q0XMH/NOPB supports start-up into prebiased output loads - a critical feature for hot-swap and system-level power management. During prebias start-up, the internal soft-start circuit ramps the feedback reference from the existing output voltage level (not from 0 V) at the same 600 µs rate, preventing reverse current flow and avoiding output overshoot or undershoot. This behavior is confirmed in the LM26420 datasheet (SNVS579L) Section 7.3.1 and enables safe integration in systems where downstream rails may already be powered when the LM26420Q0XMH/NOPB is enabled.

What package type and thermal characteristics apply to the LM26420Q0XMH/NOPB?

The LM26420Q0XMH/NOPB uses the HTSSOP-20 (PWP) package measuring 6.50 mm × 4.40 mm with an exposed die attach pad (DAP) that must be soldered to a thermal pad on the PCB. Its junction-to-ambient thermal resistance (RθJA) is 38.5°C/W under JEDEC JESD51-7 conditions. The DAP provides the primary thermal path; proper PCB copper area and via count beneath the pad are essential to maintain junction temperature below 125°C under full 2 A/channel load. Thermal shutdown activates at 165°C with automatic recovery at ~150°C.