Monolithic Power Systems Inc. MP1720DH-9-LF-Z

Overview

MP1720DH-9-LF-Z from Monolithic Power Systems is a mono Class-D audio amplifier delivering 2.7W into 4Ω at 10% THD+N with 5V supply, featuring pin-selectable 1MHz/1.3MHz switching frequency, 9dB fixed gain, and integrated 250mΩ MOSFETs. It operates in MSOP-10EP package with thermal pad, supports differential or single-ended input, and eliminates startup/shutdown pop via 15ms controlled turn-on sequence - deployed in space-constrained portable audio systems requiring low-EMI operation without output LC filters.

For engineers reviewing the MP1720DH-9-LF-Z datasheet, MP1720DH-9-LF-Z pinout, MP1720DH-9-LF-Z application, or MP1720DH-9-LF-Z equivalent, key selection criteria include its 9dB gain configuration, 53μV typical output noise at 3.3V, 90% peak efficiency, FCC-compliant radiated emissions performance with 24-inch unshielded cable, and thermal shutdown protection at +125°C junction temperature.

Technical Context

The MP1720DH-9-LF-Z implements a fully differential BTL (bridge-tied load) Class-D architecture with internal sawtooth-based PWM modulation and comparator-driven gate control. Its oscillator supports three modes: CLK=GND (1.0MHz), CLK=FLOAT (1.3MHz), or external TTL synchronization (0.5–1.4MHz), enabling EMI spectral spreading away from sensitive bands.

It integrates dual 250mΩ power MOSFETs per half-bridge, full thermal and short-circuit protection with auto-recovery, and bias voltage generation for differential inputs (820–900mV common-mode range). Startup pop suppression is achieved via controlled 15ms bias ramp-up, while shutdown draws only 0.1μA.

Key Specifications

Pinout & Package

MP1720DH-9-LF-Z uses the MSOP-10EP (exposed pad) package: 3mm × 4.9mm body, 0.5mm pitch, thermal pad soldered to PCB ground for enhanced thermal dissipation (θJA = 105°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5086RTJR and TPA2013D1YZFT, MP1720DH-9-LF-Z delivers superior EMI performance without filters, lower noise (53μV vs. ≥70μV), and tighter thermal management via exposed pad - making it optimal for space- and noise-sensitive portable designs where fixed 9dB gain is acceptable.

Availability

MP1720DH-9-LF-Z is available at Aetrix Electronics and suitable for smartphone audio subsystems, wireless headset driver stages, portable media player output amplifiers, and IoT voice assistant speaker modules requiring stable component supply, RoHS-compliant packaging, and production-ready lead times.

Supply support for MP1720DH-9-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 series belongs to MPS's Class-D audio amplifier product line, engineered specifically for ultra-low-EMI, high-efficiency mono audio output in battery-powered portable electronics - prioritizing integration, thermal resilience, and regulatory compliance over programmability.

FAQ

What is the recommended input configuration for MP1720DH-9-LF-Z in noisy environments?

For noisy environments such as smartphones with RF transceivers or PMIC switching noise, the MP1720DH-9-LF-Z should be used with fully differential input. Its common-mode rejection ratio exceeds 66dB, and the internal bias (820–900mV for the -9 variant) allows direct connection to DC-biased codecs without coupling capacitors - reducing component count and preserving low-frequency response.

Does MP1720DH-9-LF-Z require an output LC filter to meet EMC standards?

No. The MP1720DH-9-LF-Z passes FCC radiated emissions standards with up to 24 inches of unshielded twisted-pair speaker cable and no external LC filter, thanks to its proprietary low-EMI modulation scheme and optimized edge rates. This eliminates two inductors and two capacitors from the BOM and saves ≥12 mm² PCB area.

How does the 9dB gain option affect system-level signal chain design?

The 9dB fixed gain (2.7–3.0 V/V) matches typical line-out or DAC output levels (0.8–1.2V_RMS) directly, eliminating need for external gain-setting resistors or op-amp buffers. This simplifies layout, reduces component cost, and avoids additional noise sources - ideal for cost-sensitive, high-volume portable audio designs.

What thermal considerations apply when using MP1720DH-9-LF-Z in a sealed enclosure?

The MSOP-10EP package requires the exposed thermal pad to be soldered to a minimum 100 mm² copper pour connected to DGND/PGND. In sealed enclosures, derating is necessary: at 2.7W output, ambient temperature must stay below +60°C to maintain junction temperature ≤125°C (θJA = 105°C/W). Forced airflow or thermal vias improve margin.

Can MP1720DH-9-LF-Z synchronize to an external clock, and what is the valid frequency range?

Yes. When CLK is driven with a TTL-compatible square wave, MP1720DH-9-LF-Z synchronizes its switching frequency to the external source across 0.5–1.4MHz. This allows precise EMI placement - for example, shifting harmonics away from GSM or Wi-Fi bands - while maintaining regulation stability and THD+N performance.

What protection features are built into MP1720DH-9-LF-Z, and how do they recover?

MP1720DH-9-LF-Z includes thermal shutdown (trip at +125°C, resume at +112°C) and cycle-by-cycle short-circuit protection. After fault detection, the device disables all MOSFETs for ≥50μs before attempting automatic recovery. No latch-up occurs, and normal operation resumes without external reset if fault condition clears.

Is MP1720DH-9-LF-Z compatible with single-ended input sources?

Yes, but with limitations. Single-ended input requires AC coupling capacitors and biases one input at mid-supply via resistor divider. For MP1720DH-9-LF-Z, this reduces maximum input swing and achievable output power - especially at low gains. Differential input is strongly preferred for full 2.7W capability and optimal noise immunity.