Monolithic Power Systems Inc. MPQ3426DL-AEC1-LF-Z

Overview

MPQ3426DL-AEC1-LF-Z from Monolithic Power Systems is an AEC-Q100 Grade 1 qualified 6A, 45V current-mode boost converter with integrated 90mΩ MOSFET, configurable 300kHz–2MHz switching frequency, 3.2V–22V input bias range, and 35V max output voltage. It delivers fast transient response for automotive pre-boost applications under cold-crank conditions.

For engineers reviewing the MPQ3426DL-AEC1-LF-Z datasheet, MPQ3426DL-AEC1-LF-Z pinout, MPQ3426DL-AEC1-LF-Z application, or MPQ3426DL-AEC1-LF-Z equivalent, key selection criteria include UVLO hysteresis programmability via EN resistor divider, external compensation for ceramic-capacitor stability, soft-start capacitor control of inrush current, and thermal shutdown at 160°C.

Technical Context

The MPQ3426 employs peak-current-mode control with a transconductance error amplifier (160μA/V gain), internal 1.225V reference, and 6μA soft-start current source. Its FSET pin sets switching frequency linearly via external resistor (e.g., 84.5kΩ yields 540kHz), while COMP pin enables full loop compensation using R-C network for pole-zero placement.

It integrates a 6A/45V/90mΩ N-channel MOSFET switch with cycle-by-cycle current limiting, under-voltage lockout on VIN (2.75V–3.15V threshold), and independent EN UVLO hysteresis controlled by external resistors. The dual ground structure separates AGND (error amp reference) from PGND (switch return) to suppress noise coupling.

Key Specifications

Pinout & Package

MPQ3426DL-AEC1-LF-Z uses a QFN-14 (3mm × 4mm) package with wettable flanks optional (GRE variant); this variant has a 3mm × 4mm body, 0.5mm pitch, exposed thermal pad (EP), and 14 terminals arranged in two rows. Pin 1 is marked by a corner chamfer or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost converter applications.

Compared with MPQ3426DL-AEC1-LF-Z, MPQ3425-AEC1-Z trades current capability for lower cost and thermal footprint, while LM5122MQ/NOPB offers design flexibility and higher voltage tolerance at the expense of BOM count, layout complexity, and automotive qualification.

Availability

MPQ3426DL-AEC1-LF-Z is available at Aetrix Electronics and suitable for automotive cold-crank pre-boost, audio tuner bias supplies, and OLED display bias applications requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for MPQ3426DL-AEC1-LF-Z 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

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance power management ICs for automotive, industrial, and consumer markets, with global manufacturing and quality certifications.

The MPQ3426 belongs to MPS's AEC-Q100-qualified automotive boost converter product line, designed specifically for robust pre-boost, cold-crank support, and high-efficiency DC-DC conversion in safety-critical vehicle subsystems.

FAQ

What is the minimum input voltage required for startup?

The MPQ3426DL-AEC1-LF-Z starts up when VIN rises above 2.75V (typical) with 250mV hysteresis. For cold-crank operation, it reliably initiates regulation at 3.2V input, as confirmed in the Recommended Operating Conditions table. EN pin programming can adjust effective UVLO but does not lower the fundamental VIN threshold.

Can the MPQ3426 drive a 24V/1A load from a 12V input?

Yes - with VIN = 12V and VOUT = 24V, the device delivers 1A continuously using the typical application circuit (Figure 5). At 300kHz switching frequency and 15μH inductor, efficiency exceeds 92%, and thermal performance remains within limits when mounted on a 2-layer PCB with 2oz copper and thermal vias to the EP pad.

How is switching frequency set, and what resistor gives 600kHz?

Switching frequency is set by connecting a resistor from FSET (Pin 14) to AGND. Per Table 1, a 66.5kΩ resistor yields ~620kHz; for 600kHz, use 68kΩ (standard value). The relationship is f_SW(MHz) ≈ 0.86 / R_FSET(MΩ), with R_FSET in kΩ yielding f_SW in MHz.

Is the exposed pad (EP) electrically connected, and how should it be soldered?

Yes - the EP is internally connected to PGND and serves as the primary thermal and electrical ground path. It must be soldered to a solid copper pour with ≥6 thermal vias (0.3mm diameter) connecting to inner ground planes. Per JEDEC MO-229, coplanarity must be ≤0.10mm; insufficient solder paste or voiding causes thermal derating.

Does the MPQ3426 support discontinuous conduction mode (DCM)?

Yes - the MPQ3426 operates in DCM at light loads, automatically transitioning from CCM to DCM as load decreases. This is inherent to its peak-current-mode architecture and reduces light-load quiescent current to ~650μA, improving efficiency below 10% load without requiring external mode-control pins.

What is the maximum output capacitance supported with external compensation?

No hard upper limit exists, but stability depends on compensation network selection. With 4.7μF–22μF ceramic output capacitors, Table 2 provides validated R_COMP/C_COMP values. For >22μF, recalculate f_P1 = 1/(2π·R_LOAD·C_OUT) and adjust R_COMP to maintain phase margin >45°, verified via load-step testing.

How does the EN pin function during micro-power shutdown?

When EN voltage falls below 0.45V (typical), the device enters micro-power shutdown drawing <1μA. EN rising above 1.4V (typical) initiates startup; hysteresis is programmable via external resistor divider to prevent chatter during slow-rising VIN, as detailed in Application Information section "EN UVLO Hysteresis".