Monolithic Power Systems Inc. MPM3805AGQBE-AEC1-Z

Overview

MPM3805AGQBE-AEC1-Z from Monolithic Power Systems is an AEC-Q100 qualified, synchronous step-down DC/DC power module integrating MOSFETs and a 0.47µH inductor in a QFN-12 (2.5mm×3.0mm×0.9mm) package. It delivers up to 0.6A peak output current from a 2.6V–6V input, regulates output down to 0.6V, and features constant-on-time (COT) control with 100% duty cycle capability for automotive low-dropout operation.

For engineers reviewing the MPM3805AGQBE-AEC1-Z datasheet, MPM3805AGQBE-AEC1-Z pinout, MPM3805AGQBE-AEC1-Z application, or MPM3805AGQBE-AEC1-Z equivalent, key selection considerations include its integrated inductor simplifying layout, automotive-grade thermal range (−40°C to +125°C), EN/PG pins enabling precise power sequencing, hiccup-mode short-circuit protection, and minimal external component count (only two ceramic capacitors and two FB resistors required).

Technical Context

The MPM3805AGQBE-AEC1-Z employs a constant-on-time (COT) control architecture with input voltage feed-forward, delivering stable ~3.5MHz switching frequency across input and output conditions while enabling fast transient response without complex loop compensation. Its internal high-side and low-side MOSFETs feature RDSON_P ≤ 180mΩ and RDSON_N ≤ 140mΩ, paired with a monolithic 0.47µH inductor (RDCR = 130mΩ) to minimize conduction losses.

It operates in forced continuous conduction mode (FCCM), supports 100% duty cycle for dropout operation, and integrates comprehensive fault protection: cycle-by-cycle over-current limiting (typ. 2.1A P-FET limit), thermal shutdown at 150°C with 30°C hysteresis, and open-drain power-good (PG) with ±10% regulation window and 550kΩ internal pull-up.

Key Specifications

Pinout & Package

MPM3805AGQBE-AEC1-Z is housed in a thermally enhanced QFN-12 package measuring 2.5mm × 3.0mm × 0.9mm, with exposed thermal pad on underside for efficient heat dissipation in automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down module applications.

Compared with TPS82084SILR and LMZ31503RVQR, the MPM3805AGQBE-AEC1-Z uniquely balances AEC-Q100 qualification, ultra-compact footprint, integrated sensing (OUT_S), and COT-based transient performance-making it optimal for cost-sensitive, space-limited automotive subsystems demanding robustness and simplicity.

Availability

MPM3805AGQBE-AEC1-Z is available at Aetrix Electronics and suitable for automotive ECU power, rear camera modules, eCall telematics, and infotainment display subsystems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MPM3805AGQBE-AEC1-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 analog and power ICs, with design centers across Asia and North America and global manufacturing partnerships.

The MPM3805A product line delivers fully integrated, AEC-Q100 qualified DC/DC modules targeting automotive subsystems where reliability, small size, and simplified design are critical-especially in camera, telematics, and body electronics.

FAQ

What is the maximum allowable input voltage for MPM3805AGQBE-AEC1-Z?

The absolute maximum input voltage is 6.5V. Operation above 6V risks permanent damage. The recommended operating range is 2.6V to 6V, covering automotive battery variations including cold-crank (down to ~2.6V) and load-dump transients (clamped externally). Exceeding 6.5V violates absolute maximum ratings and voids AEC-Q100 qualification guarantees.

Does MPM3805AGQBE-AEC1-Z require an external compensation network?

No external compensation is required. The constant-on-time (COT) control architecture eliminates the need for loop compensation components. Stability is inherently ensured by the internal control scheme and proper placement of the recommended input/output capacitors (e.g., 10µF ceramic at VIN, 20µF at VOUT). This simplifies design and reduces risk of instability due to layout parasitics.

How does the OUT_S pin improve regulation accuracy?

The OUT_S pin provides remote sensing of the output voltage at the load, compensating for IR drop across PCB traces between the module's OUT pins and the actual load. When connected directly to the load's power input, it enables tighter load regulation (±1% typical vs ±3% without sensing), especially critical in high-current or long-trace automotive applications like camera sensor rails.

Can MPM3805AGQBE-AEC1-Z operate in dropout mode?

Yes-it supports 100% duty cycle operation, allowing VOUT to track VIN down to within the minimum dropout voltage (determined by RDSON_P × ILOAD). At 0.6A load and 180mΩ high-side RDS(ON), dropout is ~108mV, enabling stable regulation even when VIN falls to just above VOUT + 0.11V-essential for cold-crank survival in automotive systems.

What is the purpose of the NC pins (3 and 4) on the QFN-12 package?

Pins 3 and 4 are internally connected to the switch node (SW) and are not intended for external connection. They serve as thermal and electrical extensions of the internal high-side/low-side MOSFET junction and must remain unconnected and unrouted on the PCB. Soldering or routing to these pins may cause malfunction or reliability failure.

Is the power-good (PG) signal compatible with 3.3V logic systems?

Yes. PG is an open-drain output with internal 550kΩ pull-up to VIN. When VIN ≥ 3.3V, PG pulls high to VIN (≥3.3V), exceeding standard 3.3V logic high thresholds. For VIN < 3.3V (e.g., 2.6V cold-crank), PG still meets 3.3V system logic-low requirements when asserted low, and external pull-up to 3.3V can be added if needed for interfacing.

How does hiccup-mode short-circuit protection behave during sustained fault conditions?

Upon detecting over-current, the device disables switching, discharges the soft-start capacitor, waits ~10ms, then attempts soft-start again. If the short persists, it repeats this cycle indefinitely-limiting average power dissipation to safe levels (<100mW) and preventing thermal damage. Recovery is automatic once the fault clears, with no reset signal required.