Monolithic Power Systems Inc. MP7748SGF-P

Overview

MP7748SGF-P from Monolithic Power Systems is a fully integrated 2×20W stereo single-ended or 50W mono bridge-tied-load (BTL) Class D audio amplifier IC. It integrates dual 250mΩ N-channel power MOSFETs per channel, programmable undervoltage protection (UVP), startup/shutdown pop elimination, and thermal/short-circuit protection. It delivers 20W per channel into 4Ω at 24V with 0.02% THD+N (1W, 8Ω SE) and operates from 9.5V to 36V for flat-panel TV and multimedia computer audio subsystems.

For engineers reviewing the MP7748SGF-P datasheet, MP7748SGF-P pinout, MP7748SGF-P application, or MP7748SGF-P equivalent, key selection criteria include output configuration flexibility (SE/BTL), UVP threshold programmability via UVP1/UVP2 pins, integrated bootstrap circuitry (BST1/BST2), thermal shutdown trip point (150°C), and AAM™ modulation architecture enabling high fidelity at >91% efficiency.

Technical Context

The MP7748SGF-P implements Monolithic Power Systems' proprietary Analog Adaptive Modulation™ (AAM™) topology - a variable-frequency, self-oscillating Class D architecture delivering fast transient response, low distortion, and single-supply operation. Its dual-channel design supports independent enable (EN1/EN2) and UVP (UVP1/UVP2) control, allowing asymmetric channel management in stereo systems.

Each channel features internal reference generation (REF1/REF2 = VDD/2), dedicated timer inputs (TIMER1/TIMER2) for pop-elimination slew-rate tuning, and dual power domains (VDD1/VDD2, PGND1/PGND2) with separate bootstrap (BST1/BST2) and switch-node (SW1/SW2) terminals. The IC uses internal high-side gate drive with external bootstrap capacitors and integrates overcurrent protection triggering at 4.5A per MOSFET leg.

Key Specifications

Pinout & Package

TSSOP28-EP package with exposed thermal pad (connected to GND plane); 28-pin surface-mount footprint optimized for thermal dissipation in space-constrained audio PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5756M and TPA3116D2, MP7748SGF-P offers unique analog-programmable UVP and dual independent timer-based pop suppression - critical for plug-and-play consumer devices where firmware complexity and startup artifacts must be avoided.

Availability

MP7748SGF-P is available at Aetrix Electronics and suitable for flat panel television audio, portable docking station subsystems, and multimedia computer speaker drivers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP7748SGF-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 power ICs, with core expertise in DC/DC conversion, LED drivers, and Class D audio amplifiers.

The MP7748 product line targets cost-sensitive, space-constrained consumer audio applications requiring high efficiency, low noise, and zero-firmware implementation - emphasizing analog configurability over digital control.

FAQ

What is the maximum recommended PCB copper area for the exposed thermal pad?

The exposed pad must be connected to a solid GND plane covering ≥120 mm² (e.g., 10 mm × 12 mm) using ≥4 thermal vias (0.3 mm diameter, filled or plated) to an inner-layer GND plane. This achieves the specified θJC = 6°C/W and prevents junction temperature exceeding 125°C at full 20W/channel output.

Can MP7748SGF-P operate in mono BTL mode with only one channel enabled?

No - BTL mode requires both channels driven differentially (SW1 and SW2) into a single load. Enabling only EN1 or EN2 forces single-ended operation. For true BTL, both EN1 and EN2 must be high, with IN1 and IN2 driven with inverted signals and REF1/REF2 tied together.

How does the programmable UVP function interact with the EN pin?

UVP and EN operate independently: UVP triggers automatic shutdown when VDD falls below the programmed threshold (e.g., 9.5V), while EN provides manual on/off control. If both are active, UVP takes priority - the amplifier remains disabled even if EN is high until VDD rises above the UVP hysteresis level (e.g., 9.5V + 0.3V).

What LC filter component values are validated for 24V/4Ω SE operation?

Per MPS Application Note AN107, the validated SE filter uses 10 µH shielded toroidal inductors (e.g., Pulse PA4342.103NLT) and 220 µF low-ESR electrolytic capacitors (e.g., Panasonic EEU-FR1E221L). This yields f₀ ≈ 3.4 kHz and Q ≈ 0.85 - meeting flat response up to 20 kHz with <0.1 dB ripple.

Is the 2.2µF TIMER capacitor mandatory for pop elimination?

The 2.2µF value is recommended to achieve ~20mA/350ms startup slew rate, but values from 312nF to 4.7µF are supported. Lower capacitance increases slew rate (risking pop), higher capacitance slows startup (increasing mute time). Designers may optimize based on measured acoustic response in final enclosure.

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

No - MP7748SGF-P is analog-input only. It accepts differential line-level signals at IN1/IN2 referenced to REF1/REF2. Digital audio interfaces require external DAC or converter; this IC focuses on analog amplification with minimal external components.

What is the minimum recommended input coupling capacitor value for 20Hz–20kHz bandwidth?

For 8Ω load and 20Hz lower cutoff, CIN ≥ 1/(2π × 20Hz × 8Ω) ≈ 1000 µF. However, typical designs use 2.2 µF–10 µF because the amplifier's input impedance is set by RIN (e.g., 10 kΩ), making effective corner frequency f = 1/(2π × RIN × CIN). With RIN = 10 kΩ and CIN = 2.2 µF, f ≈ 7.2 Hz - safely below audio band.