Monolithic Power Systems Inc. MP2364DF-LF-Z

Overview

MP2364DF-LF-Z from Monolithic Power Systems is a dual-channel synchronous step-down DC/DC converter IC with integrated 0.18Ω high-side and 10Ω low-side MOSFETs per channel, delivering 1.5A continuous output current per channel across 4.75V–23V input range, fixed 1.4MHz switching frequency, and 0.92V internal reference for adjustable outputs from 0.92V to 16V - used in DSL modems and set-top boxes for dual-rail I/O and core supply generation.

For engineers reviewing the MP2364DF-LF-Z datasheet, MP2364DF-LF-Z pinout, MP2364DF-LF-Z application, or MP2364DF-LF-Z equivalent, key selection considerations include per-channel soft-start control (SSA/SSB), independent enable/UVLO (ENA/ENB), thermal shutdown at 160°C, cycle-by-cycle overcurrent protection, and compatibility with low-ESR ceramic output capacitors in TSSOP20F package with exposed pad.

Technical Context

The MP2364DF-LF-Z implements current-mode control per channel with transconductance error amplifiers (GEA = 630–1230 µA/V) and slope-compensated peak-current sensing, enabling fast transient response and stable operation with ceramic output capacitors. Its 1.4MHz oscillator sets switching timing, while short-circuit foldback reduces frequency to 210kHz under fault conditions.

Each channel features independent feedback (FBA/FBB), compensation (COMPA/COMPB), and soft-start (SSA/SSB) pins, supporting configurable dual-output or single-output (2×1.5A) operation. The internal bootstrap circuitry (BSA/BSB) enables high-side gate drive, and the 9kΩ soft-start pin output resistance allows precise RC ramp time control (Ramp Time = 2.2 × 9kΩ × C).

Key Specifications

Pinout & Package

TSSOP20F package with exposed thermal pad (θ_JA = 40°C/W, θ_JC = 6°C/W); 0.65mm pitch, 4.4mm × 6.5mm footprint; RoHS-compliant, lead-free (LF), tape-and-reel (Z).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-channel buck regulator applications.

Compared with RTQ2134B-QT and TPS54290PWP, the MP2364DF-LF-Z delivers best-in-class integration for sub-23V dual-rail applications - combining 1.5A capability, 1.4MHz fixed frequency, and full protection in a single TSSOP20F package without external power switches or complex compensation tuning.

Availability

MP2364DF-LF-Z is available at Aetrix Electronics and suitable for DSL modems, set-top boxes, distributed I/O systems, and industrial embedded controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2364DF-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 design centers in the US, China, and Taiwan, and global distribution through authorized partners.

The MP2364 belongs to MPS's high-efficiency DC/DC converter product line, engineered for space-constrained consumer and industrial applications requiring dual independent buck regulation with minimal external components and robust fault protection.

FAQ

What is the maximum allowable input voltage for MP2364DF-LF-Z?

The absolute maximum input voltage at INA and INB pins is 25V. Continuous operation above 23V violates the Recommended Operating Conditions and risks permanent damage. The device is rated for 4.75V–23V input range, with 23V being the upper limit for reliable long-term operation under all temperature and load conditions.

Can MP2364DF-LF-Z operate with only one channel enabled?

Yes - ENA and ENB are independent; grounding ENB while applying >2.62V to ENA enables Channel A only. The disabled channel draws <1µA, and its SWB, FBB, COMPB, SSB, BSB pins remain high-impedance. This configuration supports single-output operation with 1.5A capability and preserves all protections on the active channel.

Is an external Schottky diode required for proper operation?

Yes - the MP2364DF-LF-Z uses asynchronous rectification; an external Schottky diode (e.g., B230A) is mandatory between SWx and PGB/PGA to conduct inductor current when the low-side MOSFET is off. Omitting it causes catastrophic failure due to reverse voltage stress on the internal 10Ω low-side switch.

How does the soft-start function work, and what capacitor value achieves a 5ms ramp time?

SSA and SSB pins have 9kΩ internal output resistance; ramp time = 2.2 × 9kΩ × C. For 5ms, solve C = 5ms / (2.2 × 9kΩ) ≈ 253nF - use 220nF or 270nF standard value. The soft-start voltage ramps linearly, delaying FB regulation until target output is reached, preventing inrush current into bulk capacitance.

What thermal derating applies when using the TSSOP20F package without a thermal pad connection?

Without soldering the exposed pad to a thermal plane, θ_JA degrades from 40°C/W to ≥80°C/W. At 1.5A per channel and 12V input, power dissipation is ~0.6W; junction temperature rise would exceed 120°C above ambient - derate output current to ≤0.9A per channel or add ≥2cm² copper pour under the pad to maintain T_J <125°C.

Does MP2364DF-LF-Z support synchronization to an external clock?

No - the MP2364DF-LF-Z uses an internal 1.4MHz oscillator with no external sync input pin. Frequency is fixed and non-adjustable; attempting to override it via external signal is not supported and may cause instability or damage. For synchronizable alternatives, consider MPS MP2451 or TI TPS54290.

What is the minimum output voltage achievable with the internal 0.92V reference?

The minimum regulated output is 0.92V - the feedback reference voltage itself. The device cannot regulate below this value because the error amplifier compares FB to 0.92V; setting R1 = 0 in the divider yields V_OUT = 0.92V × (1 + R1/R2) = 0.92V. Lower voltages require external reference or different IC.