Monolithic Power Systems Inc. MP7722DF-LF-P

Overview

MP7722DF-LF-P from Monolithic Power Systems is a stereo Class D audio amplifier IC delivering 2 × 20W into 4Ω loads at 24V, featuring integrated 180mΩ MOSFETs, single-supply operation (9.5–24V), THD+N of 0.06% at 1W/8Ω, and thermally enhanced TSSOP-20EP packaging. It serves as the core power stage in compact stereo audio systems requiring high efficiency (>93% at 20W) and low-noise performance (190µV typical).

For engineers reviewing the MP7722DF-LF-P datasheet, MP7722DF-LF-P pinout, MP7722DF-LF-P application, or MP7722DF-LF-P equivalent, key selection criteria include its single-ended output architecture, bootstrap-driven high-side gate control, integrated pop elimination, thermal shutdown at 150°C, and dual-channel enable logic requiring EN1/EN2 tied together.

Technical Context

The MP7722DF-LF-P implements MPS's proprietary Analog Adaptive Modulation™ topology operating at up to 1MHz idle switching frequency, enabling low distortion and fast transient response without external clocking. Its dual-channel architecture uses independent timing capacitors (CINT1/CINT2) and feedback resistors to set channel-specific gain and quiescent frequency.

Each channel integrates matched 180mΩ N-channel MOSFETs in half-bridge configuration with bootstrap gate drive (BS1/BS2 pins), supporting single-ended speaker connection via external LC filters. Internal protection includes cycle-by-cycle short-circuit detection (5.0A limit), thermal shutdown with 30°C hysteresis, and active pop suppression during startup/shutdown.

Key Specifications

Pinout & Package

MP7722DF-LF-P is housed in a thermally enhanced 20-pin TSSOP package with exposed pad (TSSOP20F-EP), optimized for PCB heat dissipation via soldered thermal pad connected to PGND. The package supports θJA = 40°C/W on 1"² 1 oz copper.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stereo Class D audio amplifier applications.

Compared with TAS5722LRTJR and TPA3116D2PWPR, MP7722DF-LF-P offers optimal balance of analog input simplicity, compact TSSOP-20EP footprint, and proven pop-free startup-making it ideal for cost-sensitive, space-constrained consumer audio where analog sources dominate.

Availability

MP7722DF-LF-P is available at Aetrix Electronics and suitable for surround sound DVD systems, flat panel monitors, and televisions requiring stable component supply, consistent parametric performance across production lots, and long-term lifecycle support.

Supply support for MP7722DF-LF-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 analog and mixed-signal ICs for power management and audio applications, headquartered in California with global design centers.

The MP7722 belongs to MPS's second-generation Class D audio amplifier product line, engineered specifically for compact, high-efficiency stereo audio systems in consumer electronics where thermal constraints and board space limit traditional linear or discrete switcher solutions.

FAQ

What is the minimum recommended LC filter configuration for MP7722DF-LF-P?

The datasheet specifies a typical LC filter of 10µH inductor and 0.47µF capacitor per channel. This combination yields a characteristic frequency (~730kHz) that effectively attenuates switching harmonics while preserving full 20kHz audio bandwidth. Inductor selection must prioritize soft saturation behavior and sufficient RMS current rating for 20W into 4Ω (≥3.2A).

How does the MP7722DF-LF-P handle power supply pumping in single-ended configurations?

MP7722DF-LF-P mitigates supply pumping through mandatory use of a large bulk electrolytic capacitor (≥2200µF) on the VDD rail, which absorbs charge injected during switch transitions. Layout best practices-including tight VDD/PGND loops and localized 1µF X7R bypasses at VDD1/VDD2-further suppress voltage overshoot. Operating above 20V requires additional capacitance margin.

Can EN1 and EN2 be driven independently?

No-EN1 and EN2 must be tied together and driven simultaneously. The datasheet explicitly states "EN1 must be connected to EN2" and "drive EN1 high to enable MP7722." Independent control would disrupt internal bias sequencing and may cause channel imbalance or undefined startup behavior.

What is the purpose of the NC pins (1, 5, 11, 16) and how should they be handled on the PCB?

Pins 1, 5, 11, and 16 are No Connect-internally unconnected die pads. They must remain electrically floating: no traces, vias, or solder mask openings. Leaving them unconnected avoids parasitic coupling; grounding or routing them risks introducing noise or compromising thermal performance of the exposed pad.

Does MP7722DF-LF-P support 8Ω loads at full rated power?

At 24V, MP7722DF-LF-P delivers 10W per channel into 8Ω (vs. 20W into 4Ω), as confirmed by the "Operating Specifications" table. Efficiency rises to 95% at 1W/8Ω, but maximum continuous output is limited by current capability and thermal design-not voltage swing alone.

How is thermal performance affected by the exposed pad connection?

The exposed pad is electrically connected to PGND and is the primary thermal path. Soldering it to a ≥1"² copper pour with ≥4 thermal vias (0.3mm diameter) to inner ground planes reduces θJA from 40°C/W to ≤28°C/W, enabling full 20W/channel operation without forced air or heatsink in ambient ≤60°C.

What causes the 500ms delay between EN assertion and audio output?

The 500ms delay is intentional firmware-controlled ramp-up time for internal bias generation, reference stabilization, and output capacitor pre-charging. This sequence ensures all internal nodes reach correct DC operating points before enabling the power stage-eliminating turn-on pop and preventing output stage latch-up.