Monolithic Power Systems Inc. MP24895GJ-Z

Overview

MP24895GJ-Z from Monolithic Power Systems is a step-down white-LED driver IC with internal 36V MOSFET, designed for continuous-current operation across 6V–36V input and delivering up to 1A LED current. It employs hysteretic control for fast transient response, uses high-side current sensing with 100mV feedback reference, and supports simultaneous PWM and analog dimming on the EN/DIM pin-enabling automotive interior lighting, emergency signage, and low-voltage halogen replacement systems.

For engineers reviewing the MP24895GJ-Z datasheet, MP24895GJ-Z pinout, MP24895GJ-Z application, or MP24895GJ-Z equivalent, key selection criteria include its 1000:1 PWM dimming resolution, thermal shutdown at 150°C, UVLO threshold of 5.3V (typ), 0.2Ω R_DS(on), and TSOT23-5 package compatibility with space-constrained LED lighting PCBs.

Technical Context

The MP24895GJ-Z implements a fixed-frequency hysteretic control architecture that regulates LED current by comparing the voltage across an external high-side sense resistor (RS) to a 100mV ±6mV reference. Its internal 1.275V bandgap reference feeds both the EN/DIM pull-up and current-sense comparator, enabling dual-mode dimming without external bias circuitry.

Operation requires no external compensation: the hysteretic loop inherently stabilizes via inductor current ripple, achieving sub-100ns minimum on/off times (100ns/80ns) and eliminating phase-margin concerns. The IC integrates under-voltage lockout (4.7V–5.9V hysteresis), thermal shutdown (150°C with 15°C hysteresis), and 0.2Ω MOSFET with 1.1W power dissipation limit in TSOT23-5.

Key Specifications

Pinout & Package

MP24895GJ-Z is housed in a TSOT23-5 package (2.9mm × 1.6mm × 0.9mm), optimized for compact LED driver layouts. The exposed pad is not electrically connected; thermal performance relies on PCB copper area under Pin 2 (GND).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP24895GJ-Z, MPQ24895GJ-A adds automotive qualification but shares identical pinout and electrical specs, while LT3474EDD requires external FET and compensation - increasing design effort but enabling higher current and frequency tuning.

Availability

MP24895GJ-Z is available at Aetrix Electronics and suitable for automotive interior lighting, emergency signage, and low-voltage halogen replacement requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MP24895GJ-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 MP24895 belongs to MPS's LED driver product line, engineered specifically for cost-sensitive, space-constrained constant-current LED applications operating directly from wide-input industrial and automotive supplies.

FAQ

What is the recommended value for the current-sense resistor (R_SET) to achieve 700mA LED current?

Per the datasheet equation R_SET = 100mV / I_LED, a 700mA target requires R_SET = 0.143Ω. Standard 1% E96 value 0.143Ω (or nearest 0.140Ω/0.147Ω) yields ±1.5% current accuracy. Use 1206 or larger case size for 0.5W power rating to handle 50mW dissipation at full load.

Can MP24895GJ-Z drive more than one LED string in parallel?

No - the MP24895GJ-Z is a single-string constant-current driver. Parallel LED strings require individual current regulation per string to prevent thermal runaway; using one MP24895GJ-Z for multiple strings causes mismatched current distribution and potential overcurrent in lower-V_F strings.

Does the EN/DIM pin require external pull-up or pull-down resistors for reliable PWM dimming?

No external pull-up is needed - the IC internally pulls EN/DIM to 1.275V. For PWM dimming, drive the pin directly with a logic-level square wave (min 1.5V amplitude); adding a series NPN transistor (e.g., MMBT3904) isolates the PWM source from the internal reference and prevents duty-cycle distortion.

What is the maximum achievable switching frequency with MP24895GJ-Z?

The MP24895GJ-Z does not have a user-adjustable switching frequency - it operates in hysteretic mode with variable frequency dependent on input voltage, output current, and inductor value. Typical operating frequency ranges from 200kHz to 600kHz under standard conditions (VIN=18V, I_LED=1A, L=47µH).

Is an output capacitor required for stable LED current regulation?

An output capacitor is not required for basic operation, as the inductor provides inherent current filtering. However, if peak-to-peak LED current ripple must be <40% of average current (e.g., for flicker-sensitive applications), add a 2.2µF ceramic capacitor across the LED string terminals.

How does the TSOT23-5 package's thermal performance compare to the QFN-6 variant?

The TSOT23-5 has θ_JA = 110°C/W and max 1.1W power dissipation, limiting continuous 1A operation to ambient temperatures ≤65°C with minimal copper pour. The QFN-6 offers θ_JA = 50°C/W and 2.5W rating - enabling full 1A operation up to 85°C ambient with standard 2-layer PCB layout.