Monolithic Power Systems Inc. MP1740EC-LF-Z

Overview

MP1740EC-LF-Z 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 (at 3.6V), and WLCSP-9 package. It operates from 2.5V to 5.5V, achieves 0.1% THD+N at 1.8W/4Ω, and targets space-constrained mobile audio systems requiring low pop/noise and GSM supply rejection.

For engineers reviewing the MP1740EC-LF-Z datasheet, MP1740EC-LF-Z pinout, MP1740EC-LF-Z application, or MP1740EC-LF-Z equivalent, key selection criteria include its 250kHz switching frequency, 37μVRMS A-weighted output noise, 1ms startup time, integrated short-circuit and thermal protection, and differential-input CMRR-enhanced noise immunity in RF-sensitive handset designs.

Technical Context

The MP1740EC-LF-Z implements a fixed-frequency PWM-based Class-D modulation scheme with internal 250kHz oscillator, enabling predictable EMI filtering and stable operation across 2.5–5.5V supply range. Its fully differential input stage supports common-mode input from 0.5V to VCC–0.8V and eliminates need for coupling capacitors when biased within spec.

It integrates dual power MOSFETs per half-bridge leg (R_DS(on) = 300mΩ at 3.6V), analog and power ground separation (AGND/PGND), and independent AVCC/PVCC rails to suppress supply coupling. Startup logic ensures 1ms pop-free enable with internal de-pop circuitry and UVLO thresholds at 2.48V (rising) and 2.1V (falling).

Key Specifications

Pinout & Package

The MP1740EC-LF-Z uses a 9-ball Wafer-Level Chip Scale Package (WLCSP) with 0.5mm pitch, 1.6mm × 1.5mm footprint, and 0.34mm max height. Ball layout follows JEDEC MO-211 DD variant with coplanarity ≤0.05mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPA2013D1RTJR and MAX9718EWC+T, the MP1740EC-LF-Z uniquely combines differential input (eliminating coupling caps), 91% efficiency, and WLCSP-9 size-making it optimal for ultra-thin RF-exposed mobile audio where PCB area, noise immunity, and battery life are co-constrained.

Availability

MP1740EC-LF-Z is available at Aetrix Electronics and suitable for smartphone audio amplification, wireless headset driver circuits, and portable media player output stages requiring stable component supply, consistent parametric performance, and RoHS-compliant packaging.

Supply support for MP1740EC-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 distribution through authorized partners.

The MP1740 belongs to MPS's Class-D audio amplifier product line, engineered specifically for space- and efficiency-critical mobile endpoints-delivering high-fidelity audio with minimal external components and robust RF resilience.

FAQ

What is the recommended input coupling capacitor value for single-ended source interfacing?

For single-ended sources, use 2.2μF X5R/X7R ceramic capacitors with ±10% tolerance. This sets corner frequency below 50Hz when paired with 150kΩ input resistors, ensuring full-bandwidth audio response while blocking DC offset. Place capacitors as close as possible to INP/INN balls to minimize noise pickup on high-impedance nodes.

Does MP1740EC-LF-Z require external bootstrap capacitors for the H-bridge?

No. The MP1740EC-LF-Z integrates all necessary charge-pump and level-shift circuitry for its internal MOSFET gates. No external bootstrap or flying capacitors are needed-only AVCC and PVCC decoupling (1μF + 10μF ceramics) per datasheet Figure 2 layout guidelines.

How does the device handle GSM burst noise on the PVCC rail?

The MP1740EC-LF-Z achieves –62dB supply ripple rejection (KSVR) at 217Hz via separate AVCC/PVCC domains and optimized internal regulation. This suppresses amplitude modulation of audio output caused by GSM transmit bursts, eliminating audible "buzz" without requiring additional LC filtering on the power rail.

Can the gain be adjusted beyond the default 2V/V configuration?

Yes. Gain is set by external resistor ratio per GAIN = (R1/Ri) × (R3/R2). Using 150kΩ input resistors yields 2V/V; increasing Ri to 300kΩ reduces gain to 1V/V for improved noise margin, while decreasing Ri to 75kΩ raises gain to 4V/V-provided input signal swing remains within common-mode limits and THD+N stays within spec.

What is the thermal derating behavior above +25°C ambient?

With θ_JA = 114°C/W, maximum continuous power drops linearly: at +60°C ambient, P_OUT must be limited to ~0.7W to keep junction temperature ≤125°C. Thermal shutdown activates at 140°C, but sustained operation above 125°C degrades long-term reliability-use copper pour and thermal vias under PGND/AGND balls to improve heat dissipation.

Is the WLCSP-9 package compatible with standard SMT reflow profiles?

Yes. The MP1740EC-LF-Z WLCSP-9 conforms to J-STD-020D moisture sensitivity level 1 and supports standard lead-free reflow profiles (peak 260°C, <60 sec above 217°C). Ensure solder paste volume matches 0.25mm ball height and use stencil aperture 0.35mm × 0.35mm for reliable void-free joints.

Does the device support I²S or digital input interfaces?

No. The MP1740EC-LF-Z is an analog-input Class-D amplifier only. It accepts fully differential or single-ended analog audio signals on INP/INN. Digital audio interfaces (I²S, PDM) require external DAC or codec; this device functions strictly as a power output stage.