Monolithic Power Systems Inc. MP1720DQ-3-LF-Z

Overview

MP1720DQ-3-LF-Z from Monolithic Power Systems is a mono Class-D audio amplifier delivering 2.7W into 4Ω at 5V with 10% THD+N, featuring pin-selectable 1MHz/1.3MHz switching frequency, integrated 250mΩ MOSFETs, and full-bridge BTL output architecture. It operates across 2.5V–5.5V supply, achieves 90% efficiency, and eliminates startup/shutdown pop via 15ms controlled turn-on.

For engineers reviewing the MP1720DQ-3-LF-Z datasheet, MP1720DQ-3-LF-Z pinout, MP1720DQ-3-LF-Z application, or MP1720DQ-3-LF-Z equivalent, key selection criteria include its 3dB fixed gain, QFN10 (3mm × 3mm) package with exposed thermal pad, FCC-compliant EMI performance without output LC filter, and differential input support for noise-critical portable audio designs.

Technical Context

The MP1720DQ-3-LF-Z implements a fully differential Class-D modulator with internal sawtooth oscillator and comparator-based PWM generation, enabling BTL output drive without external LC filtering. Its clock input supports three modes: GND (1.0MHz), floating (1.3MHz), or external TTL synchronization (500kHz–1.4MHz).

It integrates thermal shutdown (>125°C trip, >112°C recovery), short-circuit protection, and low-quiescent-current operation (4mA @ 3.3V, 0.1μA in shutdown). Input bias voltage is fixed at 950–1035mV for the -3 variant, supporting both differential and single-ended configurations with defined common-mode input limits.

Key Specifications

Pinout & Package

MP1720DQ-3-LF-Z is housed in a thermally enhanced 10-pin QFN package (3mm × 3mm, 0.5mm pitch) with an exposed thermal pad (Pin 10) that must be soldered to PCB ground for thermal management and electrical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5086EVM and MAX9718ETA+, MP1720DQ-3-LF-Z uniquely balances filterless FCC compliance, differential input noise immunity, and pin-selectable switching frequency - making it optimal for space-constrained, battery-powered portable audio where layout simplicity and acoustic reliability are prioritized over raw power headroom.

Availability

MP1720DQ-3-LF-Z is available at Aetrix Electronics and suitable for smartphone audio subsystems, wireless headset driver circuits, and portable media player designs requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.

Supply support for MP1720DQ-3-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 manufacturing partnerships.

The MP1720 product line targets portable audio applications demanding high efficiency, low EMI, and minimal external components - specifically engineered for smartphones, wearables, and IoT voice interfaces where thermal, size, and acoustic integrity are critical.

FAQ

What is the exact gain setting for MP1720DQ-3-LF-Z?

The MP1720DQ-3-LF-Z has a fixed voltage gain of 3dB (1.3–1.5 V/V), confirmed in the Electrical Characteristics table under "Voltage Gain AV" for MP1720-3. This corresponds to a nominal 1.4× amplification ratio and is factory-trimmed - no external resistor configuration is required or supported.

Can MP1720DQ-3-LF-Z drive an 8Ω speaker?

Yes - it delivers 1.56W into 8Ω at 5V and 10% THD+N, per the Operation Characteristics table. Output power scales inversely with load impedance, so 8Ω operation is valid but yields ~56% less power than 4Ω. Thermal derating must be observed: maximum continuous dissipation in QFN10 is 2.5W at +25°C ambient.

Is the thermal pad (Pin 10) electrically connected to ground?

Yes - the exposed thermal pad (Pin 10, labeled PVIN/Thermal Pad) must be soldered to a PCB copper pour tied directly to PGND. This serves dual purposes: providing the power ground return path for the H-bridge and conducting heat away from the die. Floating or isolated pad connections will cause thermal shutdown and output instability.

Does MP1720DQ-3-LF-Z require input coupling capacitors?

Only if the source is single-ended or its DC bias falls outside 0.2–1.9V. The MP1720DQ-3-LF-Z supports DC-coupled differential inputs within that common-mode range - eliminating C_IN. For SE sources, a 1μF–10μF X7R ceramic capacitor is recommended to form a high-pass filter with the 15kΩ input impedance, preventing low-frequency saturation.

How does the CLK pin affect EMI performance?

Setting CLK=GND (1.0MHz) or CLK=FLOAT (1.3MHz) shifts fundamental switching harmonics away from sensitive RF bands (e.g., GSM, Bluetooth). External clock synchronization further spreads spectral energy, enabling system-level EMI tuning - verified to pass FCC radiated emissions with 24-inch unshielded cable and zero output filter.

What happens during thermal shutdown?

When junction temperature exceeds +125°C, the MP1720DQ-3-LF-Z disables all output MOSFETs and enters latched-off state for ≥50μs. Normal operation resumes only after die temperature drops below +112°C. This hysteresis prevents oscillation near trip point and protects against sustained overload or poor heatsinking.

Is MP1720DQ-3-LF-Z compatible with lithium-polymer battery voltage profiles?

Yes - its 2.5V–5.5V operating range covers full Li-Po discharge curve (4.2V down to 2.7V). At 2.5V, it still delivers 0.64W into 4Ω (10% THD+N), and quiescent current remains stable at 3.5mA, ensuring usable audio output even at end-of-charge without brownout reset or gain shift.