Monolithic Power Systems Inc. MP24893DQ-LF-P

Overview

MP24893DQ-LF-P from Monolithic Power Systems is a step-down white LED driver IC with 6V–36V input range, internal 36V/1A MOSFET, hysteretic control architecture, 200mV typical feedback reference voltage, and dual PWM/analog dimming via EN/DIM pin-designed for automotive decorative lighting and emergency signage requiring stable high-brightness LED current regulation.

For engineers reviewing the MP24893DQ-LF-P datasheet, MP24893DQ-LF-P pinout, MP24893DQ-LF-P application, or MP24893DQ-LF-P equivalent, key selection criteria include input voltage headroom, high-side current-sense resistor tolerance impact on LED current accuracy, thermal resistance (θJA = 50°C/W) in QFN6 package, and compatibility with 100Hz–2kHz PWM dimming signals.

Technical Context

The MP24893DQ-LF-P implements a fixed-frequency hysteretic control loop that regulates LED current by comparing the voltage across an external high-side sense resistor to a 202mV ±30mV reference, eliminating need for loop compensation. Its internal 36V MOSFET supports up to 1A continuous output current with minimum on/off times of 100ns each.

Dimming is implemented through the EN/DIM pin: analog dimming accepts 0.3V–2.5V DC to scale LED current from 25% to 200%, while PWM dimming uses 100Hz–2kHz square waves with ≥1.5V amplitude. Under-voltage lockout triggers at 5.3V (rising) with 700mV hysteresis, and thermal shutdown activates at 150°C junction temperature.

Key Specifications

Pinout & Package

MP24893DQ-LF-P is housed in a RoHS-compliant, thermally enhanced QFN6 package (3mm × 3mm, 0.95mm height) with exposed thermal pad. Pin 6 is NC; all other pins are electrically active and validated per Monolithic Power Systems' Rev. 1.02 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP24895DQ-LF-Z, MP24893DQ-LF-P offers identical pinout but lower efficiency and narrower dimming bandwidth; versus LM3409QMY/NOPB, it integrates the power switch and lowers sense loss but sacrifices frequency programmability and maximum input voltage headroom.

Availability

MP24893DQ-LF-P is available at Aetrix Electronics and suitable for automotive decorative lighting, emergency signage, and low-voltage halogen replacement requiring stable component supply and legacy design continuity.

Supply support for MP24893DQ-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 mixed-signal ICs for power management, motion control, and interface applications.

The MP24893 belongs to MPS's WLED driver product line, engineered specifically for cost-sensitive, thermally constrained LED lighting systems operating directly from wide-range DC inputs without intermediate regulation.

FAQ

What is the recommended value for the current-sense resistor (R_SENSE) when driving 1A LEDs?

R_SENSE = 202mV / 1A = 0.202Ω. A standard 0.2Ω, 1% tolerance, 1W metal-film resistor is recommended. Layout must minimize parasitic inductance between IN and RS pins to avoid current-sense error during fast switching transitions.

Can MP24893DQ-LF-P operate with input voltage below 6V?

No. The absolute minimum input voltage is 6V per datasheet specifications. Below 5.3V, under-voltage lockout disables the device. Attempting operation at 5.5V will result in intermittent startup or complete shutdown due to UVLO hysteresis.

Is the EN/DIM pin internally pulled up, and what voltage does it default to?

Yes - the EN/DIM pin has an internal 45kΩ pull-up to a 1.275V reference. When left open, the pin sits at ~1.28V, enabling full-output operation. This internal bias serves as both enable threshold and analog dimming reference baseline.

Does MP24893DQ-LF-P require an output capacitor for stable operation?

No output capacitor is required for basic operation. However, if peak-to-peak LED current ripple must be kept below 30% of average current, a 2.2µF ceramic capacitor placed directly across the LED string reduces ripple proportionally - verified in typical application circuits on page 10 of the datasheet.

How does the hysteretic control affect EMI performance compared to current-mode controllers?

Hysteretic control produces variable switching frequency depending on input voltage and load, which spreads energy across a wider spectrum and reduces narrowband EMI peaks. However, this makes EMI filtering less predictable than fixed-frequency controllers - layout attention to SW node area and ground integrity is critical.

What is the maximum allowable power dissipation for MP24893DQ-LF-P at 85°C ambient temperature?

Using θ_JA = 50°C/W: P_D(MAX) = (150°C − 85°C) / 50°C/W = 1.3W. This assumes adequate PCB copper area under the thermal pad; actual dissipation must stay below 1.3W to avoid thermal shutdown during continuous 1A operation.

Why is MP24893 "not recommended for new designs," and what changes does MP24895 introduce?

MPS discontinued MP24893 for new designs due to MP24895's superior specs: lower IQ (0.5mA vs. 0.7mA), higher efficiency (96% vs. 94%), extended PWM dimming range (10kHz vs. 2kHz), and improved thermal resistance (45°C/W vs. 50°C/W). MP24895 maintains pin compatibility and identical footprint.