Monolithic Power Systems Inc. MP7748SGF-Z

Overview

MP7748SGF-Z from Monolithic Power Systems is a dual-channel Class D audio amplifier IC capable of 2 × 30W stereo single-ended output into 4Ω loads or 60W mono bridge-tied-load (BTL) output into 8Ω, operating from a single 9.5V–36V supply with integrated 200mΩ MOSFETs and programmable undervoltage protection. It delivers THD+N of 0.02% at 1W/8Ω and >90% efficiency at 10% THD in BTL mode, targeting high-fidelity audio subsystems in flat-panel displays and home entertainment systems.

For engineers reviewing the MP7748SGF-Z datasheet, MP7748SGF-Z pinout, MP7748SGF-Z application, or MP7748SGF-Z equivalent, key selection criteria include its dual-mode output architecture (SE/BTL), integrated pop-elimination timing control, thermal/short-circuit protection thresholds, and TSSOP28-EP package thermal performance under continuous 30W/channel load conditions.

Technical Context

The MP7748SGF-Z implements MPS' proprietary Analog Adaptive Modulation™ (AAMTM) topology with variable switching frequency up to 1MHz, enabling fast transient response and excellent linearity without external compensation. Its dual independent channels feature separate EN, UVP, TIMER, REF, and AGND/PGND domains to support asymmetric configuration and channel-specific shutdown sequencing.

Each channel integrates matched 200mΩ N-channel power MOSFETs in half-bridge topology, driven by bootstrap circuits (BST1/BST2 to SW1/SW2), with internal overtemperature shutdown at 150°C (30°C hysteresis) and short-circuit current limiting at 5.5A peak per FET. Startup pop elimination is implemented via controlled slew-rate charging of output coupling capacitors using externally set timer capacitors (e.g., 2.2μF on TIMER1/TIMER2).

Key Specifications

Pinout & Package

The MP7748SGF-Z is housed in a thermally enhanced TSSOP28-Exposed Pad package. The exposed pad must be soldered to a PCB ground plane for optimal thermal dissipation (θJC = 6°C/W). Pin numbering follows standard TSSOP layout with dual-channel symmetry and dedicated analog/power ground separation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5825P and MAX98357A, the MP7748SGF-Z uniquely combines high-power dual-mode output (SE/BTL), hardware-programmable UVP, and integrated MOSFETs in a thermally optimized package - making it the sole option for self-contained 30W+ stereo or 60W mono Class D designs without external controllers or power stages.

Availability

MP7748SGF-Z is available at Aetrix Electronics and suitable for flat panel televisions, home theater soundbars, and portable docking stations requiring stable component supply and long-term production continuity.

Supply support for MP7748SGF-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 two decades of leadership in DC/DC converters, motor drivers, and Class D audio solutions.

The MP7748SGF-Z belongs to MPS' high-efficiency Class D audio amplifier product line, engineered specifically for space-constrained consumer electronics where thermal performance, pop-free operation, and single-supply simplicity are mandatory design requirements.

FAQ

What is the maximum safe operating voltage for MP7748SGF-Z?

The absolute maximum supply voltage is 40V, but the recommended operating range is 9.5V to 36V. Exceeding 36V risks permanent damage to internal MOSFETs and gate drivers, as confirmed by Absolute Maximum Ratings table (page 3). Operation above 36V voids warranty and triggers immediate thermal shutdown even at room temperature.

Can MP7748SGF-Z drive 2Ω speakers in stereo SE mode?

No. The datasheet specifies 30W output only into 4Ω loads in SE mode. Driving 2Ω loads exceeds the 5.5A short-circuit current limit per channel and violates SOA limits - sustained operation causes thermal shutdown or MOSFET failure. For lower impedances, use BTL mode into 4Ω (not 2Ω) with appropriate LC filter redesign.

How is startup pop eliminated without external circuitry?

MP7748SGF-Z integrates a controlled-current source that charges output coupling capacitors (COUT) during startup. The slew rate is set by external TIMER1/TIMER2 capacitors (e.g., 2.2μF), limiting inrush to ~20mA/350ms. This prevents large DC transients at the speaker terminals, verified in Typical Performance Curves (page 7–14).

What is the purpose of separate AGND1/AGND2 and PGND1/PGND2 pins?

AGND1/AGND2 provide low-noise reference for analog inputs (IN1/IN2) and references (REF1/REF2); PGND1/PGND2 carry high di/dt switching currents from SW1/SW2. Separating these grounds minimizes coupling of switching noise into the audio signal path - a requirement validated in Application Information section (page 17–19) and EVB layout guidelines.

Does MP7748SGF-Z support I²S or other digital audio interfaces?

No. MP7748SGF-Z accepts only analog differential inputs (IN1/IN2 referenced to REF1/REF2). It lacks digital interface circuitry, decoders, or sample-rate converters. Audio must be provided as line-level analog signals - confirmed by Block Diagram (page 14) and Input Coupling Capacitor section (page 18).

What LC filter component values are recommended for 60W BTL into 8Ω?

For 60W BTL at 30V, MPS recommends 10μH inductors and 220μF film capacitors per channel (Figure 4, page 18). The characteristic filter frequency should be ~25kHz (Q ≈ 0.85) to pass full 20Hz–20kHz bandwidth while attenuating 600kHz+ switching artifacts - values validated in Table 3 and Typical Performance Curves (pages 11–14).

Is the exposed thermal pad electrically isolated?

Yes. The exposed pad is internally connected to PGND (pin 28), not to any signal or power net. It must be soldered to a solid PCB ground plane with ≥4 thermal vias (0.3mm diameter) to achieve θJC = 6°C/W. Leaving it floating degrades thermal performance by >40%, risking premature thermal shutdown at <25W output.