Monolithic Power Systems Inc. MP18851-A4CGY-P

Overview

MP18851-A4CGY-P from Monolithic Power Systems is an isolated, dual-input, independent dual-channel gate driver IC with 4A peak source/sink current per channel, 50ns typical propagation delay, and >100kV/µs common-mode transient immunity (CMTI). It drives high-side and low-side power switches in isolated half-bridge topologies using proprietary capacitive isolation, supporting up to 30V secondary-side supply and operating across –40°C to +125°C for offline AC/DC and isolated DC/DC converters.

For engineers reviewing the MP18851-A4CGY-P datasheet, MP18851-A4CGY-P pinout, MP18851-A4CGY-P application, or MP18851-A4CGY-P equivalent, this device delivers verified functional isolation between secondary-side drivers (1500V_DC in SOIC-16 WB), configurable UVLO thresholds (3V option), TTL/CMOS-compatible inputs, and dual independent enable/disable control-critical for robust high-voltage power stage design and safety-compliant system integration.

Technical Context

The MP18851-A4CGY-P implements two fully independent gate driver channels separated by MPS's capacitive isolation barrier, enabling separate ground references (VSSA/VSSB) and independent VDDA/VDDB supplies up to 30V. Its input logic accepts 2.8–5.5V VDDI with internal pull-down on INA/INB and dual enable/disabled control (EN/DIS pins).

It supports flexible output configurations: half-bridge HS/LS mode or dual independent drivers, with propagation delay matching ≤6ns and pulse-width distortion ≤6ns. The SOIC-16 WB package provides 5kV_RMS isolation (UL 1577) and 6000V_PK reinforced insulation (VDE 0884-17), certified to GB 4943.1-2011.

Key Specifications

Pinout & Package

MP18851-A4CGY-P is packaged in SOIC-16 WB (wide-body), providing 5kV_RMS isolation and 8mm minimum creepage/clearance. Pin functions are validated per MPS datasheet Rev. 1.0 (2022).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel isolated gate driver applications.

Compared with Si823Hx and UCC5390SCD, MP18851-A4CGY-P uniquely provides both EN and DIS pins for hardware-redundant shutdown, 3V UVLO option for tighter gate-drive margin control, and full independence of secondary-side supplies-enabling safer, more flexible, and thermally optimized designs in high-reliability isolated power systems.

Availability

MP18851-A4CGY-P is available at Aetrix Electronics and suitable for industrial isolated DC/DC converters, EV onboard chargers, and renewable energy inverters requiring stable component supply, long-term lifecycle support, and certified reinforced isolation.

Supply support for MP18851-A4CGY-P 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 over 20 years of expertise in DC/DC conversion, motor drivers, and isolated gate drivers.

The MP18851 product line delivers high-CMTI, dual-channel isolated gate drivers targeting high-density, high-efficiency power supplies and inverters where safety certification, thermal robustness, and timing precision are critical.

FAQ

What is the UVLO threshold for MP18851-A4CGY-P?

The "A4C" suffix denotes the 3V UVLO option: VDDA/VDDB UVLO threshold is 2.7V (min), 3.2V (typ), and 3.7V (max) when falling, with 200–400mV hysteresis. This ensures gate drive only activates when secondary supply exceeds safe margin for 12V logic-level MOSFETs, preventing weak turn-on and conduction loss.

Can MP18851-A4CGY-P drive SiC MOSFETs?

Yes. Its 4A peak source/sink current, 50ns propagation delay, >100kV/µs CMTI, and 30V output supply support fast-switching SiC MOSFETs. The SOIC-16 WB package's 5kV_RMS isolation and 6000V_PK VDE rating meet requirements for 750V–1200V SiC-based OBCs and solar inverters.

How does the EN and DIS pin functionality differ?

EN is active-high with internal pull-up; DIS is active-high with internal pull-down. Both independently disable outputs: pulling EN low or DIS high shuts down both channels. This dual-control architecture enables fail-safe shutdown via either controller GPIO or external fault signal, satisfying ASIL-B functional safety requirements.

What package does MP18851-A4CGY-P use, and why does it matter?

MP18851-A4CGY-P uses SOIC-16 WB (wide-body), offering 5kV_RMS isolation (UL 1577), 6000V_PK reinforced insulation (VDE 0884-17), and >8mm creepage/clearance. This package meets reinforced insulation requirements for industrial and EV applications where basic insulation (e.g., SOIC-16 NB) is insufficient.

Does MP18851-A4CGY-P require external bootstrap diodes or capacitors?

No. MP18851-A4CGY-P is a galvanically isolated driver with independent VDDA/VSSA and VDDB/VSSB supplies - it does not rely on bootstrap circuits. Each channel is powered directly from its own isolated secondary-side rail, eliminating bootstrap diode/capacitor dependencies and associated reliability concerns in high-duty-cycle applications.

What certifications apply to MP18851-A4CGY-P?

MP18851-A4CGY-P (SOIC-16 WB) is UL 1577 recognized (E322138), DIN EN IEC 60747-17 (VDE 0884-17):2021-10 certified (40055265), and CQC certified per GB 4943.1-2011. It provides reinforced insulation with 630V_RMS working voltage and 6000V_PK transient rating - validated for end-equipment safety compliance.

How is thermal performance characterized for this part?

Thermal derating curves for safety-limiting current and power are published per package (SOIC-16 WB). At 25°C ambient, max safety power is 2215mW; at 100°C, it derates to ~1300mW. These curves - based on θ_JA = 56°C/W - enable accurate junction temperature estimation and PCB copper area planning for continuous 125°C operation.