Monolithic Power Systems Inc. MP1740EC-LF-P

Overview

MP1740EC-LF-P from Monolithic Power Systems is a mono Class-D audio amplifier delivering 3W into 4Ω at 5V with 91% efficiency, fully differential input architecture, integrated 300mΩ H-bridge MOSFETs (VCC=3.6V), and 9-ball WLCSP package. It operates from 2.5V to 5.5V, achieves 0.1% THD+N at 1.8W/4Ω, and targets space-constrained mobile audio output stages.

For engineers reviewing the MP1740EC-LF-P datasheet, MP1740EC-LF-P pinout, MP1740EC-LF-P application, or MP1740EC-LF-P equivalent, key selection criteria include BTL output drive capability, GSM power supply ripple rejection (–62 dB at 217 Hz), 1 ms pop-free startup, 37 μVRMS A-weighted output noise, and thermal shutdown protection for battery-powered handheld systems.

Technical Context

The MP1740EC-LF-P implements a fixed-frequency (250 kHz typical) PWM-based Class-D modulation scheme with internal triangular waveform generation and comparator-driven gate logic. Its fully differential input eliminates need for coupling capacitors when common-mode voltage is maintained between 0.5V and VCC–0.8V.

It integrates dual power domains (AVCC/AGND and PVCC/PGND), independent analog and power ground paths, and internal short-circuit and thermal protection. The device uses a single-ended enable signal (EN) with 1.6V high-threshold and 0.4V low-threshold to control startup/shutdown sequencing without external timing components.

Key Specifications

Pinout & Package

MP1740EC-LF-P uses a 9-ball Wafer-Level Chip-Scale Package (WLCSP) with 0.5 mm pitch and 1.6 mm × 1.5 mm footprint. Ball layout follows JEDEC MO-211 DD variant with coplanarity ≤ 0.05 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TAS5707RTAT and MAX9718EWE+T, MP1740EC-LF-P offers superior GSM noise immunity (–62 dB vs. –45 dB), smallest footprint (1.6 mm × 1.5 mm), and lowest shutdown current (0.5 μA), making it optimal for ultra-compact, battery-sensitive mobile audio endpoints.

Availability

MP1740EC-LF-P is available at Aetrix Electronics and suitable for wireless handsets, smart wearables, portable medical devices, and IoT voice terminals requiring stable component supply across production lifecycles.

Supply support for MP1740EC-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 for power management, motor control, and audio applications.

The MP1740 belongs to MPS's Class-D audio amplifier product line, designed specifically for space-constrained, battery-powered mobile devices requiring high efficiency, low noise, and robust RF immunity without external passive complexity.

FAQ

What is the minimum recommended input coupling capacitor value when using single-ended source?

When using a single-ended input outside the common-mode voltage range (0.5V to VCC–0.8V), a 2.2 μF ceramic capacitor is recommended per input leg. This sets the high-pass corner frequency below 20 Hz for full-bandwidth audio, avoids phase shift in voice band, and maintains ≥10% tolerance to prevent CMRR degradation due to capacitance mismatch.

Can MP1740EC-LF-P drive an 8Ω speaker at full rated power?

No. At 8Ω, maximum output power is 1.65W (1% THD+N, 5.5V supply). The device is optimized for 4Ω loads; driving 8Ω reduces thermal stress but sacrifices loudness. For 8Ω applications, output power drops ~45% versus 4Ω, and efficiency remains above 85% up to 1.7W P_OUT.

How does the MP1740EC-LF-P achieve GSM power supply rejection?

It combines analog input-stage PSRR enhancement (–70 dB baseline), dedicated AVCC/AGND isolation, and internal compensation that rejects 217 Hz ripple from shared Li-ion battery rails. Measured KSVR is –62 dB at 217 Hz with 400 mV_PP ripple, verified under real GSM burst conditions per datasheet test setup.

Is external gain-setting resistor matching critical for performance?

Yes. Input resistors (RI) must be matched to ±1% or better. Mismatch >2% degrades CMRR and PSRR by >10 dB, increases THD+N, and introduces common-mode feedthrough. MPS recommends 1% thin-film resistors placed adjacent to INP/INN pins to minimize parasitic imbalance.

What thermal derating applies above +25°C ambient?

With θ_JA = 114°C/W, maximum continuous power dissipation decreases linearly: at +60°C ambient, P_D(MAX) = (140°C – 60°C)/114°C/W = 0.70W. Above this, thermal shutdown activates. Board-level copper area and airflow significantly improve actual θ_JA; refer to MPS AN-107 for layout guidelines.

Does MP1740EC-LF-P support I²S or digital audio interface?

No. MP1740EC-LF-P is an analog-input Class-D amplifier only. It accepts fully differential or single-ended analog audio signals. Digital audio interfaces (I²S, PCM, PDM) require external DAC or codec; the device has no digital control pins or serial interface.

What is the purpose of separate AVCC and PVCC pins?

AVCC powers the analog front-end (input buffer, error amplifier, oscillator), while PVCC supplies the H-bridge gate drivers and power switches. Separating them prevents high-di/dt switching noise from modulating the analog reference, preserving PSRR and THD+N performance in noisy shared-rail systems.