Monolithic Power Systems Inc. MP24833GN-Z

Overview

MP24833GN-Z from Monolithic Power Systems is a 55V, 3A white LED driver IC supporting buck, boost, and buck-boost topologies with current-mode control, 200kHz fixed switching frequency, 0.198V feedback reference, and integrated 0.19Ω MOSFET - used in LCD backlight panels for notebook computers requiring precise analog/PWM dimming and open-string protection.

For engineers reviewing the MP24833GN-Z datasheet, MP24833GN-Z pinout, MP24833GN-Z application, or MP24833GN-Z equivalent, this page delivers verified topology flexibility (buck/boost/buck-boost), dual dimming interface (EN/DIM pin), OVP/short-circuit/thermal protections, SOIC8E package thermal metrics (θJA = 50°C/W), and real-world design constraints including minimum on-time (100ns) and UVLO hysteresis (200mV).

Technical Context

The MP24833GN-Z implements peak current-mode control with slope compensation to ensure stability across wide duty cycles in buck-boost operation. Its error amplifier integrates the difference between FB voltage and 0.198V reference, directly modulating peak inductor current via PWM comparator output.

It features a dedicated INGND pin enabling true ground-referenced dimming control independent of power ground, and uses BST-SW bootstrap circuitry to drive the internal high-side MOSFET. Fault handling includes foldback frequency reduction during short-circuit events and automatic recovery after OVP threshold hysteresis (60mV).

Key Specifications

Pinout & Package

MP24833GN-Z is housed in an SOIC-8 exposed pad (SOIC8E) package with θ_JA = 50°C/W and θ_JC = 10°C/W, requiring PCB copper pour under the exposed VSS pad for thermal management.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MPQ24833GD-A, MP24833GN-Z trades automotive qualification for lower unit cost and standard industrial qualification; compared with LT3466-1, it delivers double the output current, eliminates two external components (bootstrap diode + sense resistor bypass), and adds robust fault recovery not present in the older architecture.

Availability

MP24833GN-Z is available at Aetrix Electronics and suitable for LCD backlight panels, notebook computer illumination, and automotive interior lighting requiring stable component supply, consistent parametric performance across production lots, and long-term lifecycle support.

Supply support for MP24833GN-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 manufacturing partnerships.

The MP24833 belongs to MPS's white LED driver product line, engineered specifically for high-efficiency, multi-topology LED current regulation in space- and thermal-constrained applications such as portable displays and automotive cabins.

FAQ

What topologies does the MP24833GN-Z support, and how is mode selection implemented?

The MP24833GN-Z supports buck, boost, and buck-boost topologies through external component configuration - no internal mode pins or registers. Buck uses inductor between VIN and SW, diode from SW to VOUT; boost places inductor between VIN and SW, diode from VOUT to SW; buck-boost uses inductor between SW and VOUT, diode from VIN to VOUT. The IC automatically adapts control loop behavior based on feedback and OVP pin voltages.

Can the MP24833GN-Z drive LED strings without a minimum number of LEDs, and how is this achieved?

Yes - the MP24833GN-Z requires no minimum number of LEDs due to its current-mode architecture and OVP pin functionality. Unlike voltage-mode drivers that rely on minimum output voltage for regulation, it regulates based solely on FB voltage (0.198V), allowing operation even with a single LED or zero LEDs (open-circuit detection triggers shutdown before overvoltage occurs).

How does the EN/DIM pin implement both analog and PWM dimming simultaneously?

The EN/DIM pin accepts combined analog-PWM signals: applying a 100Hz–2kHz square wave with amplitude between 0.67V and 1.36V (referenced to INGND) linearly scales average LED current from 0% to 100%, while preserving PWM's high contrast ratio. This avoids separate control lines and enables MCU-driven dimming with minimal GPIO usage and no external logic.

What is the purpose of the INGND pin, and why can't it be tied to VSS?

INGND provides an isolated reference for the EN/DIM signal, enabling true differential dimming control in configurations where the LED string is referenced to a voltage other than system ground - e.g., in buck-boost with negative output or floating LED cathodes. Tying INGND to VSS disables proper dimming threshold referencing and causes incorrect turn-on/off behavior, especially under varying load conditions.

Does the MP24833GN-Z require an external Schottky diode, and what are the key selection criteria?

Yes - an external Schottky diode is mandatory for all topologies. Key criteria include reverse voltage rating ≥1.2× maximum output voltage (e.g., ≥48V for 24V LED string), average forward current ≥1.2× LED current (e.g., ≥1.2A for 1A load), and low forward voltage (≤0.5V) to minimize conduction loss. B360 (40V/3A) is validated in MPS reference designs for buck applications up to 1A.

How does the MP24833GN-Z handle thermal overload, and is there hysteresis in recovery?

Thermal shutdown activates at 150°C junction temperature, disabling the internal MOSFET until die temperature falls below ~135°C (15°C hysteresis). Recovery is automatic and does not require cycling EN/DIM; the device resumes normal operation once thermal margin is restored, with soft-start re-engaging to prevent current overshoot.

What is the minimum recommended output capacitance, and why is low ESR critical?

MPS specifies ≥2.2µF ceramic (X5R/X7R) for output capacitance. Low ESR is critical because the MP24833GN-Z's current-mode loop relies on output capacitor impedance to shape phase margin; high-ESR electrolytics introduce instability poles and cause oscillation or poor transient response, whereas X7R ceramics maintain <50mΩ ESR across temperature and frequency.