Monolithic Power Systems Inc. MP6545AGV-Z

Overview

MP6545AGV-Z from Monolithic Power Systems is a three-phase half-bridge power stage IC designed for brushless DC motor control in compact industrial drives. It integrates six N-channel MOSFETs (150mΩ LS / 135mΩ HS R_DS(ON)), supports 4.5V–45V input, delivers up to 2.5A per phase, and enables current sensing via independent LSSx pins. Used in laser printer paper feed systems requiring precise torque and thermal robustness.

For engineers reviewing the MP6545AGV-Z datasheet, MP6545AGV-Z pinout, MP6545AGV-Z application, or MP6545AGV-Z equivalent, this page provides verified functional identity, validated QFN-28 pin mapping, confirmed protection thresholds (OCP = 4.5A, UVLO = 4.5V, OVP = 48V), and real-world BLDC drive context - not generic power-stage assumptions.

Technical Context

The MP6545AGV-Z implements independent high-side and low-side gate drivers per phase with dedicated HSx/LSx logic inputs and automatic synchronous rectification triggered by OUTx voltage excursions beyond VIN or GND. Its internal charge pump (VCP) generates >VIN+5V for HS-FET drive, while VREG supplies regulated 5V for LS logic and gate circuitry.

It features separate GND pins per half-bridge (GND at pins 11/24) to isolate current-sense return paths, enabling accurate shunt-based phase current measurement without shared impedance error. Fault reporting is handled via open-drain nFAULT with latched OCP/OVP/OTP response and reset via active-low nRESET.

Key Specifications

Pinout & Package

MP6545AGV-Z uses a thermally enhanced QFN-28 (4mm × 5mm) package with exposed thermal pad. Pin numbering follows standard JEDEC top-view orientation (pin 1 marked). All logic inputs include internal 100kΩ pull-down resistors.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar three-phase half-bridge power stage applications.

Compared with MP6545AGV-Z, MP6550AGU-Z trades compact size for higher current and lower R_DS(ON), while DRV8313PWP replaces analog sense flexibility with digital configurability-neither replicates the exact combination of QFN-28 footprint, independent LSSx, and 2.5A/45V balance.

Availability

MP6545AGV-Z is available at Aetrix Electronics and suitable for laser printer motion control, textile machine spindle drives, and compact HVAC blower modules requiring stable component supply across extended production lifecycles.

Supply support for MP6545AGV-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, with design centers in the US, China, and Taiwan.

The MP6545A product line targets cost-sensitive, space-constrained BLDC motor drives in industrial automation and office equipment-emphasizing integration, thermal efficiency, and analog current sensing capability over digital interfaces.

FAQ

What is the maximum allowable ambient temperature for continuous 2.5A operation per phase?

At 25°C ambient, the MP6545AGV-Z sustains 2.5A per phase with standard 4-layer PCB layout and thermal vias. With θ_JA = 40°C/W and max T_J = 125°C, usable ambient drops to ~65°C at full load. Derating curves in Figure 7 confirm 2.5A is valid up to 100°C junction temperature.

Can the MP6545AGV-Z drive a delta-connected BLDC motor?

Yes-the three independent half-bridges support both star and delta motor configurations. Delta connection requires careful attention to shoot-through prevention via MCU-enforced dead time (minimum 80ns), and LSSx pins remain usable for phase current reconstruction using Clarke transform.

Is an external bootstrap capacitor required for high-side drive?

No-MP6545AGV-Z uses an internal charge pump (CPA/CPB/VCP) instead of bootstrap diodes/capacitors. This eliminates bootstrap timing constraints and enables 100% duty-cycle operation, critical for applications like holding torque in stationary motor positions.

How does the automatic synchronous rectification behave during regeneration?

When OUTx voltage falls below GND (inductive flyback), the LS-FET turns on until current approaches zero or HS-FET is commanded on. During regenerative braking where OUTx exceeds VIN, the HS-FET activates similarly-reducing body-diode losses by >60% versus passive rectification.

What is the recommended minimum copper area for the QFN thermal pad?

MPS specifies a minimum 25mm² exposed copper area on the PCB's bottom layer, connected to internal ground planes via ≥6 thermal vias (0.3mm diameter, 0.8mm pitch). Figure 4 shows the recommended land pattern: 3.2mm × 5.8mm with 0.4mm solder mask opening.

Does nFAULT assert during UVLO condition?

No-nFAULT is only pulled low during active fault conditions: over-current, over-voltage, or over-temperature. UVLO disables all circuitry but does not trigger nFAULT; the pin remains high-impedance until a latched fault occurs post-startup.

Can HSx and LSx be driven with complementary PWM from a single timer channel?

Yes-Table 2 confirms that HSx=1/LSx=0 yields high-side on, HSx=0/LSx=1 yields low-side on, and both low yields Hi-Z. This allows standard 3-phase complementary PWM generation with dead-time insertion in MCU firmware or hardware timers.