Monolithic Power Systems Inc. MP1720DH-6-LF-P

Overview

MP1720DH-6-LF-P 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, 6dB fixed gain, and integrated 250mΩ MOSFETs. It operates in fully differential mode, eliminates startup/shutdown pop via 15ms controlled ramp, and targets compact portable audio systems requiring high efficiency (90%) and low EMI without output LC filtering.

For engineers reviewing the MP1720DH-6-LF-P datasheet, MP1720DH-6-LF-P pinout, MP1720DH-6-LF-P application, or MP1720DH-6-LF-P equivalent, key selection criteria include its MSOP-EP package thermal performance (θJA = 105°C/W), shutdown current of 0.1μA, 53μV typical output noise at 3.3V, and FCC-radiated emissions compliance with 24-inch unshielded cable-critical for battery-powered handheld audio designs.

Technical Context

The MP1720DH-6-LF-P implements a BTL (bridge-tied load) Class-D architecture with fully differential inputs and outputs, using internal sawtooth-based PWM modulation and comparator-driven gate control to generate complementary high-side/low-side drive signals. Its oscillator supports three modes: internal 1.0MHz (CLK=GND), internal 1.3MHz (CLK=FLOAT), or external TTL synchronization (500kHz–1.4MHz).

It integrates protection logic for thermal shutdown (>125°C junction) and short-circuit detection via MOSFET current sensing, with automatic recovery after ≥50μs fault hold-off. Pop suppression is achieved by controlled bias voltage ramping during enable/disable transitions, eliminating audible transients without external circuitry.

Key Specifications

Pinout & Package

MP1720DH-6-LF-P uses a 10-pin MSOP-EP (exposed thermal pad) package, optimized for thermal dissipation in space-constrained portable applications. The exposed pad must be soldered to PCB ground for effective heat transfer 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 TPA2012D2RTJR and MAX9718ETA+T, MP1720DH-6-LF-P delivers higher output power (2.7W), superior efficiency (90%), and true differential input for noise immunity-making it optimal for EMI-sensitive, battery-limited portable audio where filter-free compliance and low noise are mandatory.

Availability

MP1720DH-6-LF-P is available at Aetrix Electronics and suitable for smartphone audio subsystems, wireless headset drivers, portable media player output stages, and IoT voice assistant speakers requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for MP1720DH-6-LF-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 over two decades of expertise in DC/DC conversion, motor control, and audio power management.

The MP1720 product line targets ultra-compact, battery-efficient portable audio applications, emphasizing EMI reduction, pop-free operation, and minimal external component count to accelerate time-to-market for consumer electronics.

FAQ

What is the maximum recommended PCB copper area for the MSOP-EP thermal pad?

The exposed thermal pad on MP1720DH-6-LF-P must be soldered to a minimum 25mm² solid copper pour connected to system ground. For continuous 2.7W output at TA = +85°C, a 4-layer board with internal ground planes and thermal vias (≥8 × 0.3mm diameter) beneath the pad is required to maintain TJ ≤ 125°C per θJA = 105°C/W specification.

Can MP1720DH-6-LF-P drive an 8Ω speaker, and what is the expected output power?

Yes, MP1720DH-6-LF-P can drive an 8Ω speaker: at 5V supply and 10% THD+N, it delivers 1.56W (typical); at 3.3V supply and 10% THD+N, output is 0.71W. Power scales with V²/R, so 8Ω operation reduces peak power by ~44% versus 4Ω but improves thermal margin and reduces current demand.

Is input coupling capacitor mandatory when using a differential audio source?

No - if the differential source provides common-mode voltage within 0.2V–1.9V (e.g., 0.94V bias for MP1720-6), input coupling capacitors may be omitted. However, omitting them passes DC offset and low-frequency noise to the speaker; use only when source bias is tightly controlled and low-frequency content is not required.

How does the CLK pin affect EMI performance in a dense PCB layout?

Setting CLK to FLOAT (1.3MHz) or synchronizing to an external clock shifts spectral energy away from sensitive bands like 2.4GHz Wi-Fi or 700MHz cellular receive. This avoids harmonic alignment with RF front-end filters and reduces near-field coupling - verified by MPS radiated emission tests with 24-inch cable and no filter.

What failure modes trigger thermal shutdown, and how quickly does recovery occur?

Thermal shutdown activates when junction temperature exceeds +125°C, disabling all MOSFETs. Recovery begins only after TJ falls below +112°C, with a minimum 50μs fault hold-off period before re-enabling. This hysteresis prevents oscillation during marginal thermal conditions and protects against sustained overload.

Does the 6dB gain option support single-ended input, and what design adjustments are needed?

Yes, MP1720DH-6-LF-P supports single-ended input by AC-coupling the signal to INP and biasing INN to VBIAS (940mV typ). A 15kΩ resistor from INN to ground sets bias; input coupling capacitor value must be selected per f_IN = 1/(2π·15kΩ·C_IN) to avoid bass attenuation below target frequency.

What is the absolute maximum voltage rating for the INP and INN pins?

The absolute maximum voltage for INP and INN is −0.5V to (VIN + 0.3V). Exceeding −0.5V risks damaging input ESD structures. With VIN = 5.5V, max allowable input is +5.8V; with VIN = 2.5V, max is +2.8V. Differential input swing must stay within ±1.9V to avoid clipping or distortion.