Monolithic Power Systems Inc. MP4601EF-LF-Z

Overview

MP4601EF-LF-Z from Monolithic Power Systems is a current-mode buck-boost white LED driver IC designed for large-size LCD TV backlighting, supporting up to 100 LEDs in series with output voltage up to VINH+63V (VINH ≤ 236V), internal 0.5Ω MOSFET switch, ±5% 200mV reference voltage, and over 1:1000 dimming ratio via combined analog/PWM control.

For engineers reviewing the MP4601EF-LF-Z datasheet, MP4601EF-LF-Z pinout, MP4601EF-LF-Z application, or MP4601EF-LF-Z equivalent, key selection criteria include high-voltage string compatibility (up to 350V), dual-dimming capability, programmable cycle-by-cycle overcurrent protection, thermal shutdown, and fault reporting via open-drain FAULT pin referenced to INGND.

Technical Context

The MP4601EF-LF-Z implements peak current-mode control with programmable slope compensation to ensure stability at duty cycles >50%. It leverages patented power leverage technology-regulating only a small portion of the LED string voltage while interfacing with a fixed high-voltage bus (VINH) and low-voltage supply (VINL = 4.5–75V).

Its architecture integrates an internal 0.5Ω MOSFET switch, error amplifier with COMP pin for loop compensation, and dedicated pins for OVP (programmable threshold), OCP (resistor-set current limit), and DGD (external dimming switch gate drive). Fault detection includes LED open (auto-recovery), LED short (latch-off with FAULT assertion), and thermal shutdown with 20°C hysteresis.

Key Specifications

Pinout & Package

MP4601EF-LF-Z is packaged in TSSOP16-EP (exposed pad) with thermal performance θ_JA = 45°C/W and θ_JC = 10°C/W, optimized for high-power LED driver thermal management in space-constrained TV backlight modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar white LED driver applications.

Compared with MP4601EF-LF-Z, MP4603EF-LF-Z offers measurable improvements in efficiency, thermal resistance, and standby current while maintaining full pin and functional compatibility-making it the direct upgrade path. LM3409HVMM/NOPB provides a discrete alternative but increases design complexity and reduces power density due to external FET requirements.

Availability

MP4601EF-LF-Z is available at Aetrix Electronics and suitable for large-screen TV backlighting, commercial signage, medical imaging displays, and broadcast monitor lighting requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for MP4601EF-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 core expertise in DC/DC conversion, LED drivers, and motor control solutions.

The MP4601 belongs to MPS's high-voltage LED driver product line, engineered specifically for energy-efficient, compact backlighting in large-format LCD panels where high string voltage, precise dimming, and thermal robustness are critical.

FAQ

What is the maximum LED string voltage supported by MP4601EF-LF-Z?

The MP4601EF-LF-Z supports LED string voltages up to VINH + 63V, where VINH is the external high-voltage bus. With VINH up to 236V, the total string voltage can reach 350V-sufficient for 100+ white LEDs in series. This is enabled by its patented power leverage architecture, which regulates only a fraction of the total string voltage.

How does the FAULT pin behave during LED short conditions?

During LED short detection-defined as FB voltage exceeding 600mV or remaining above 300mV for 480µs-the FAULT pin is actively pulled low to INGND (R_DS(on) ≈ 100Ω). It remains latched low until the EN pin is cycled. During normal operation, FAULT is high-impedance and must be externally pulled up to monitor status.

Can MP4601EF-LF-Z operate without an external high-voltage bus (VINH)?

No. The MP4601EF-LF-Z requires both VINL (4.5–75V low-voltage input) and VINH (external high-voltage bus) to function. Its power leverage architecture depends on VINH to supply most of the LED string power; VINL powers only the IC control circuitry and gate driver. Omitting VINH prevents proper regulation and may damage the device.

What is the purpose of the SLOPE pin, and how is it configured?

The SLOPE pin provides programmable ramp compensation for the peak current-mode control loop. A resistor RSLOPE from SLOPE to VSS sets the compensation slope (0.3–0.47 V/µs). This prevents sub-harmonic oscillation when duty cycle exceeds 50%, ensuring stable operation across wide input/output voltage ranges typical in TV backlight applications.

Is MP4601EF-LF-Z pin-compatible with MP4603EF-LF-Z?

Yes-MP4603EF-LF-Z is a direct pin- and function-compatible successor. All pins, package dimensions, electrical characteristics, and application circuits match. MPS explicitly recommends MP4603EF-LF-Z for new designs due to improved efficiency (99.7% vs. 99.5%), lower quiescent current (650µA vs. 850µA), and better thermal resistance.

How is LED current set, and what tolerance does the FB reference provide?

LED current is set by an external sense resistor R_FB between FB and VSS, using I_LED = 0.200V / R_FB. The FB reference voltage is specified at 200mV ±5% (190–210mV) over temperature and process, ensuring LED current accuracy within ±5% without calibration-critical for consistent panel brightness and color uniformity.

Does MP4601EF-LF-Z support analog dimming only, or can it combine with PWM?

It supports both analog and PWM dimming-and their combination. Analog dimming uses 0.7–1.5V on the DIM pin to scale LED current linearly from 0% to 100%. PWM dimming applies a 100Hz–50kHz square wave. Combining them (e.g., PWM with amplitude modulated between 0.7V–1.5V) achieves >1:1000 dimming ratio, essential for high-end TV local dimming.