Monolithic Power Systems Inc. MPM3805AGQB-Z

Overview

MPM3805AGQB-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 package. It delivers up to 0.6A peak output current across a 2.6V–6V input range, regulates output down to 0.6V with ±2% feedback voltage accuracy (600mV ±12mV), and features constant-on-time control for fast transient response-ideal for automotive camera modules and ECU power rails.

For engineers reviewing the MPM3805AGQB-Z datasheet, MPM3805AGQB-Z pinout, MPM3805AGQB-Z application, or MPM3805AGQB-Z equivalent, key selection considerations include its integrated inductor, AEC-Q100 qualification, 1.5ms soft-start, open-drain power-good indicator with ±10% trip threshold, and forced continuous conduction mode (FCCM) operation under light load.

Technical Context

The MPM3805AGQB-Z employs a constant-on-time (COT) control architecture with input-voltage feed-forward to maintain stable switching frequency (2.8–4.2MHz) across input and output variations. Its internal high-side and low-side MOSFETs feature 120–180mΩ and 70–140mΩ R_DS(ON), respectively, enabling efficient operation at light loads via proprietary FCCM management.

Protection logic includes cycle-by-cycle over-current detection (typ. 2.1A P-FET limit), hiccup-mode short-circuit recovery, thermal shutdown at 150°C with 30°C hysteresis, and UVLO with 2.4V rising threshold and 300mV hysteresis-ensuring robust operation in automotive ambient conditions from –40°C to +125°C.

Key Specifications

Pinout & Package

MPM3805AGQB-Z is housed in a thermally enhanced QFN-12 package measuring 2.5mm × 3.0mm × 0.9mm, with exposed thermal pad (PGND-connected) on the bottom 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 MPM3805AGQB-Z, MPM3610AGQV-Z trades remote sensing and compact size for higher current, while TPS82084SILR sacrifices configurability and system-level control for lower BOM count in non-automotive consumer use.

Availability

MPM3805AGQB-Z is available at Aetrix Electronics and suitable for automotive camera modules, ECU subsystems, telematics units, and E-Call systems requiring stable component supply with AEC-Q100 compliance and long-lifecycle support.

Supply support for MPM3805AGQB-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 in the US, China, and Taiwan, and global manufacturing partnerships.

The MPM3805A product line delivers fully integrated, AEC-Q100 qualified DC/DC modules targeting space-constrained automotive subsystems where reliability, thermal performance, and minimal external components are critical.

FAQ

What is the maximum recommended PCB copper thickness for thermal relief under the MPM3805AGQB-Z thermal pad?

The thermal pad (pins 1–2 and bottom exposed pad) must be soldered to a minimum 2-oz copper plane with ≥8 thermal vias (0.3mm diameter, filled or capped) connecting to inner/ground layers. Thicker copper (3–4 oz) is acceptable but requires adjusted stencil aperture and reflow profile to ensure void-free solder joint formation-verified per IPC-7095B.

Can the OUT_S pin be left unconnected if remote sensing is not required?

Yes. If remote sensing is unnecessary, connect OUT_S directly to the OUT pin at the module's output pad (not at the load). Leaving it floating may cause regulation instability or oscillation due to noise coupling into the high-gain error amplifier input.

Does the MPM3805AGQB-Z support spread-spectrum frequency modulation to reduce EMI?

No. The device uses fixed-frequency COT control with VIN feed-forward; spread-spectrum modulation is not implemented. EMI reduction relies on high switching frequency (≥2.8MHz), integrated inductor shielding, and strict PCB layout adherence-including separation of noisy SW nodes from sensitive FB/AGND traces.

What is the minimum output capacitance required for stable operation at 0.6A load?

A minimum of 10µF ceramic (X5R/X7R) is required at the OUT pins. For optimal transient response and ripple suppression at full load, 20µF is recommended. Total effective capacitance must remain ≥10µF after derating for DC bias and temperature-verified using manufacturer's K-SIM or similar tools.

How does the hiccup-mode short-circuit protection behave during sustained overload?

Upon current-limit detection, the device disables switching, discharges the soft-start capacitor, waits ~20ms, then attempts restart. If short persists, it repeats the cycle indefinitely-limiting average power dissipation to <150mW and preventing thermal damage while maintaining visibility via PG pin toggling.

Is the FB voltage reference trimmed at wafer level or post-package?

The 600mV feedback reference is laser-trimmed at wafer level, achieving ±2% initial accuracy (588–612mV) across temperature and line. No external calibration is needed, and the specification is guaranteed over the full –40°C to +125°C junction range without additional compensation.

What is the recommended minimum trace width for the VIN-to-PGND high-current path?

For 0.6A peak current and 10°C temperature rise, a 0.5mm (20mil) wide, 2-oz copper trace is sufficient. However, the datasheet mandates direct connection of VIN and PGND pins to solid copper planes-trace routing is discouraged; instead, use thermal reliefs or polygon pours with ≥3x pin width coverage.