Monolithic Power Systems Inc. MP7722DF-LF

Overview

MP7722DF-LF from Monolithic Power Systems is a stereo Class D audio amplifier IC delivering 2 × 20W into 4Ω loads at 24V, integrating dual 180mΩ MOSFET output stages, analog adaptive modulation (AAM) topology, and on-chip startup/shutdown pop elimination. It operates from a single 9.5–24V supply and targets compact high-efficiency audio systems requiring low THD+N (0.06% at 1W/8Ω) and high efficiency (93% at 20W).

For engineers reviewing the MP7722DF-LF datasheet, MP7722DF-LF pinout, MP7722DF-LF application, or MP7722DF-LF equivalent, key selection criteria include its TSSOP-20EP package with exposed thermal pad, dual-channel single-ended output architecture, integrated bootstrap circuitry for high-side drive, and thermal/short-circuit protection enabling robust operation in space-constrained consumer audio designs.

Technical Context

The MP7722DF-LF implements MPS's proprietary Analog Adaptive Modulation™ (AAM) topology - a variable-frequency PWM scheme that dynamically adjusts switching frequency to maintain low distortion (<0.16% THD+N at 1W/4Ω) and fast transient response across audio bandwidth (20Hz–20kHz). Its dual independent channels each feature dedicated VDD1/VDD2, PGND1/PGND2, BS1/BS2, and SW1/SW2 pins to minimize crosstalk and enable optimized LC filter layout.

Each channel uses two internal 180mΩ N-channel MOSFETs in half-bridge configuration with bootstrap gate drive (requiring external 1µF BS-to-SW capacitors), supporting single-ended speaker connection via external LC filters. The IC includes integrated reference generation (REF1/REF2 set to VDD/2), active pop suppression during enable/disable transitions, and thermal shutdown at 150°C with 30°C hysteresis.

Key Specifications

Pinout & Package

MP7722DF-LF is housed in a thermally enhanced 20-pin TSSOP package with exposed pad (TSSOP20F), designed for surface-mount assembly and direct thermal coupling to PCB copper. The exposed pad must be soldered to PGND for optimal thermal performance (θJC = 6°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5711PAP and TPA3116D2, MP7722DF-LF uniquely combines analog input compatibility, integrated pop elimination, and compact TSSOP-20EP packaging - making it optimal for space-constrained consumer displays and DVD players where analog signal chain simplicity is critical.

Availability

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

Supply support for MP7722DF-LF 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 core expertise in DC/DC conversion, motor drivers, and Class D audio amplifiers since 1997.

The MP7722 belongs to MPS's second-generation fully integrated Class D audio amplifier product line, engineered specifically for high-efficiency, low-EMI stereo amplification in consumer electronics where board space, thermal budget, and acoustic fidelity are tightly constrained.

FAQ

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

The datasheet specifies 10µH inductors and 0.47µF film capacitors as typical values. Inductor Q must be maintained between 0.7 and 2.0 using gapped ferrite or MPP cores; capacitor ESR should be minimized using polypropylene or polyester types. Layout requires tight coupling between SW pin and LC node to suppress ringing.

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

At 24V operation, supply pumping is mitigated by using ≥2200µF bulk electrolytic capacitance on VDD plus local 1µF X7R ceramics at VDD1/VDD2. The IC's internal current limiting prevents latch-up, but sustained pumping may trigger overvoltage protection - hence the recommendation for oversized bulk capacitance and optional split-capacitor speaker biasing per Figure 2.

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 risk undefined startup behavior or pop generation.

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

Pins 1, 5, 11, and 16 are No Connect - internally unconnected silicon. They may be left floating or tied to AGND/PGND per PCB thermal or mechanical requirements, but must never be used for signal routing or decoupling. Their presence accommodates pin-compatible variants in the same package family.

Does MP7722DF-LF support 8Ω loads at full 20W output?

No - maximum output into 8Ω is 10W (per datasheet Operating Specifications table). At 24V, 20W is only achievable into 4Ω. Driving 8Ω at 20W would require >34V supply, exceeding the 26V absolute maximum rating and risking permanent damage.

Is the exposed thermal pad electrically connected to any internal node?

Yes - the exposed pad is internally connected to PGND1 and PGND2. It must be soldered to a dedicated PGND copper area with multiple thermal vias to inner ground planes. Failure to connect it results in θJA degradation from 40°C/W to >65°C/W and potential thermal shutdown under load.