Monolithic Power Systems Inc. MP3801DH-LF-Z

Overview

MP3801DH-LF-Z from Monolithic Power Systems is a high-voltage DC-to-AC converter IC designed to drive electroluminescent (EL) lamps up to 5 in², delivering a regulated ±95V (190VPP) AC output waveform. It operates from 2.5V–5.5V DC input, supports adjustable lamp drive frequency (200–274 Hz) and boost switching frequency (50–200 kHz), and features 10nA shutdown current. Used in mobile phone keypad backlighting and handheld GPS displays.

For engineers reviewing the MP3801DH-LF-Z datasheet, MP3801DH-LF-Z pinout, MP3801DH-LF-Z application, or MP3801DH-LF-Z equivalent, key selection criteria include EL lamp voltage compliance, dual-oscillator configurability, MSOP-8 thermal resistance (θJA = 150°C/W), and compatibility with single-cell Li-ion or multi-cell alkaline/NiMH power sources.

Technical Context

The MP3801 integrates two independent functional stages: a boost converter that regulates up to +95V at CS pin, and an H-bridge driver that alternates ±95V across VA and VB terminals to generate AC lamp drive. Each stage uses a dedicated internal oscillator with external resistor control (RSW_OSC for boost frequency, REL_OSC for EL frequency).

It supports split-supply operation and enables/disables via VEN logic referenced to VDD. The device implements N-channel MOSFET switching (RDS(ON) = 9Ω typ.) and requires only one external inductor and minimal passive components-no transformer or high-voltage capacitors beyond the 100V NPO ceramic at CS.

Key Specifications

Pinout & Package

MP3801DH-LF-Z is housed in an 8-pin MSOP package with exposed thermal pad connected to GND (Pin 4). The package supports surface-mount assembly and provides θJA = 150°C/W on 1"² 1 oz copper PCB.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar EL lamp driver applications.

Compared with MP3801DH-LF-Z, MP3802DH-LF-Z offers lower conduction loss and wider lamp frequency tuning, while MAX14521EASA+ trades integration for flexibility in high-voltage switching topology-making MP3801 appropriate only for legacy repair or cost-sensitive replacement where its 190VPP/240Hz profile matches existing EL panel specs.

Availability

MP3801DH-LF-Z is available at Aetrix Electronics and suitable for mobile phone keypad backlighting, handheld GPS display illumination, and remote control button illumination requiring stable component supply and long-lifecycle support for legacy portable electronics.

Supply support for MP3801DH-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.

The MP3801 belongs to MPS's high-voltage display driver product line, engineered specifically for efficient, compact EL lamp excitation in battery-powered portable devices-prioritizing low quiescent current, dual-frequency control, and minimal external component count.

FAQ

What does "NOT RECOMMENDED FOR NEW DESIGNS" mean for MP3801DH-LF-Z?

This designation indicates Monolithic Power Systems has superseded the MP3801 with the MP3802, which offers improved RDS(ON), wider frequency range, and enhanced efficiency. MP3801 remains fully functional and supported for existing designs but is not approved for inclusion in newly initiated projects per MPS's product roadmap guidance.

Can MP3801DH-LF-Z drive EL lamps larger than 5 square inches?

No. The datasheet specifies a maximum lamp area of 5 in² under recommended operating conditions. Larger lamps increase capacitive load, causing excessive current demand, reduced output voltage regulation, and potential thermal overload-especially at higher fEL settings or elevated ambient temperatures.

Why does MP3801 require separate resistors for RSW_OSC and REL_OSC?

Independent resistor control allows simultaneous optimization of boost converter efficiency (via fSW) and EL lamp visual performance (via fEL). For example, high fSW minimizes inductor size but increases switching loss, while low fEL improves brightness but may cause visible flicker-decoupling these enables precise system-level tuning.

Is the exposed pad on the MSOP-8 package electrically connected?

Yes-the exposed thermal pad is internally connected to GND (Pin 4). It must be soldered to a PCB copper pour tied to the system ground plane to ensure proper thermal dissipation (θJC = 65°C/W) and electrical stability; floating or unconnected pads cause overheating and premature failure.

What is the role of the 100V NPO capacitor at the CS pin?

This capacitor serves as the output energy storage element for the boost stage. It smooths the pulsed LX waveform into a regulated +95V DC rail at CS, supplying stable voltage to the H-bridge. NPO dielectric ensures minimal capacitance drift over temperature and voltage-critical for maintaining consistent EL lamp brightness.

Does MP3801DH-LF-Z support PWM dimming of EL lamps?

No. The IC does not implement PWM-based brightness control. Brightness is adjusted indirectly via lamp drive frequency (fEL) using the REL_OSC resistor-higher fEL increases perceived luminance but also power consumption and audible noise. True dimming requires external enable/disable cycling, which is not recommended due to lamp stress.