Monolithic Power Systems Inc. MP6922DS-LF-Z

Overview

MP6922DS-LF-Z from Monolithic Power Systems is a dual fast turn-off intelligent synchronous rectification controller for LLC resonant converters, driving two N-channel MOSFETs with 70mV V_DS regulation, 20ns total turn-off delay, and reverse current protection. It operates from 8V–24V V_DD, supports CCM/CrCM/DCM modes up to 300kHz, and enables <600µA quiescent current in light-load latch-off mode-used in high-efficiency AC-DC adapters and LCD TV power supplies.

For engineers reviewing the MP6922DS-LF-Z datasheet, MP6922DS-LF-Z pinout, MP6922DS-LF-Z application, or MP6922DS-LF-Z equivalent, key selection criteria include dual-channel fast turn-off timing (≤35ns total delay), SOIC14 package thermal resistance (θ_JA = 86°C/W), RCP pin-based reverse current latch (100µs duration), and V_DD UVLO hysteresis (1V) for stable startup in wide-input AC-DC systems.

Technical Context

The MP6922 implements adaptive gate control using real-time V_DS sensing on both channels to regulate forward voltage drop to ~70mV and initiate turn-off before negative swing. Its blanking logic enforces ≥1µs minimum on-time and modifies turn-off threshold to +100mV during turn-on to suppress ringing-induced false triggers.

Reverse Current Protection (RCP) operates via an internal 5V reference and external resistor divider on the RCP pin; when sensed voltage exceeds 3V, both gate drivers latch off for 100µs. Light-load entry is determined by monitoring MOSFET conduction time (<2.2µs per cycle) with 120µs delay before latching, reducing quiescent current to 600µA.

Key Specifications

Pinout & Package

MP6922DS-LF-Z is supplied in SOIC14 package with exposed pad not present; thermal resistance θ_JA = 86°C/W and θ_JC = 38°C/W. Pin 1 is VS1; pin 14 is PGND. The package complies with JEDEC MS-012 variation AB and supports standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel synchronous rectification controller applications.

Compared with MP6922DS-LF-Z, MP6921DS-LF-Z sacrifices channel count and protection features for lower cost, while UCC24612DR trades integrated RCP and light-load efficiency for extended voltage range-making MP6922 the optimal balance for mainstream LLC adapters and TVs requiring both performance and compliance.

Availability

MP6922DS-LF-Z is available at Aetrix Electronics and suitable for AC-DC adapters, LCD TV power supplies, and telecom SMPS requiring stable component supply, RoHS-compliant packaging, and long-term industrial lifecycle support.

Supply support for MP6922DS-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 analog and power ICs, with over 20 years of expertise in DC-DC conversion, motor drivers, and power management.

The MP6922 belongs to MPS's intelligent synchronous rectification controller product line, designed specifically to replace Schottky diodes in high-frequency resonant converters while meeting global energy efficiency mandates like Energy Star and DOE Level VI.

FAQ

What is the maximum drain voltage rating supported by MP6922DS-LF-Z on VD1 and VD2 pins?

The MP6922DS-LF-Z supports up to +180V on both VD1 and VD2 pins under absolute maximum conditions, verified per datasheet Section "Absolute Maximum Ratings". This allows direct interfacing with high-voltage secondary-side MOSFETs in LLC converters with 265VAC input and center-tapped outputs, without external voltage clamping.

How does the RCP function interact with the gate driver during normal operation?

The RCP function monitors voltage on the RCP pin via an external resistor divider; when it exceeds 3V, both VG1 and VG2 outputs are latched low for exactly 100µs. During this period, the internal driver remains inactive and ignores EN, VD, or VS signals-ensuring complete isolation of synchronous FETs during reverse current events in CCM mode.

Can MP6922DS-LF-Z operate in CrCM mode without external timing components?

Yes. MP6922DS-LF-Z natively supports CrCM operation using its internal zero-current detection based on V_DS slope analysis. No external timing capacitors or resistors are required-the IC automatically adapts blanking and turn-off thresholds to maintain stable regulation across CrCM, DCM, and CCM modes.

What is the purpose of the LL pin, and how is its timing calculated?

The LL pin sets light-load latch-off timing using an external resistor: T_LL = 2.2µs × (R_LL / 100kΩ). For example, a 100kΩ resistor yields 2.2µs pulse width; increasing to 200kΩ extends it to 4.4µs. This adjusts sensitivity to light-load conditions, allowing fine-tuning of efficiency vs. transient response trade-offs.

Is the SOIC14 package thermally superior to SOIC8E for high-current applications?

No-SOIC8E has lower θ_JA (50°C/W) than SOIC14 (86°C/W) due to its exposed thermal pad. However, SOIC14 offers higher continuous power dissipation (1.5W vs. 2.5W for SOIC8E) because its larger body and dual PGND pins improve heat spreading in PCB layouts without thermal vias, making it preferable for sustained 30A+ loads.

Does MP6922DS-LF-Z require external bootstrap capacitors for gate drive?

No. MP6922DS-LF-Z uses direct low-side gate drive architecture with integrated high-current pull-down (3A) and regulated pull-up (14V max), eliminating need for bootstrap circuits. Gate drive is referenced to VS1/VS2, enabling simple PCB layout and compatibility with standard logic- and standard-level N-channel MOSFETs.

How does the 70mV V_DS regulation impact MOSFET selection?

The 70mV regulation target means the IC dynamically adjusts gate voltage to maintain that forward drop-so MOSFETs must have sufficiently low r_DS(on) to achieve it at rated current. For 15A output, r_DS(on) ≤ 4.7mΩ is recommended; higher values cause the IC to saturate gate drive, increasing switching loss and reducing efficiency.