Monolithic Power Systems Inc. MP3383GS-Z

Overview

MP3383GS-Z from Monolithic Power Systems is a 4-string step-up WLED controller with peak-current-mode control, driving up to 400mA per string at up to 80V output voltage. It regulates LED current via external ISET resistor, supports direct PWM and analog dimming (via ADIM), and integrates four matched current sources achieving 1.8% inter-string matching accuracy for large LCD backlighting systems.

For engineers reviewing the MP3383GS-Z datasheet, MP3383GS-Z pinout, MP3383GS-Z application, or MP3383GS-Z equivalent, key selection criteria include its 6–33V input range, configurable 450–550kHz switching frequency, cascading capability for multi-IC LED arrays, OVP/OTP/LED open-short protection, and SOIC-16 package compatibility with thermal pad grounding.

Technical Context

The MP3383GS-Z implements fixed-frequency peak-current-mode control using an external ROSC resistor to set fSW between 450–550kHz. Its internal 12V LDO (VCC) powers the gate driver when VIN > 13V and features 500mV UVLO hysteresis.

Four independent current-sink channels regulate LED strings with 1.8% matching accuracy and 250mV regulation voltage at 100mA. Protection logic monitors VLEDx, OVP, ISENSE, and die temperature to disable faulty strings or latch off under overvoltage, overtemperature, or short-circuit conditions.

Key Specifications

Pinout & Package

MP3383GS-Z is housed in a 16-pin SOIC package with exposed thermal pad (EP), requiring EP connection to GND for thermal management and noise reduction. Pin numbering follows standard SOIC-16 layout (pin 1 = LED1, pin 16 = GND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar WLED controller applications.

Compared with MP3383GS-Z, MPQ3383-AEC1 adds automotive reliability at higher cost and thermal derating, while RT8589GSP trades configurability and voltage headroom for integration simplicity and fixed-frequency EMI control.

Availability

MP3383GS-Z is available at Aetrix Electronics and suitable for desktop LCD flat-panel displays, All-in-One PCs, and 2D/3D LCD TVs requiring stable component supply, long-term production continuity, and RoHS-compliant packaging.

Supply support for MP3383GS-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 power management ICs, with over two decades of expertise in DC-DC conversion, LED drivers, and motor control solutions.

The MP3383 product line targets large-format LCD backlighting, delivering high-efficiency, multi-string WLED control with integrated protection and dimming flexibility for consumer and industrial displays.

FAQ

What is the minimum input voltage required for MP3383GS-Z to start switching?

The MP3383GS-Z requires VIN ≥ 6V to operate, but startup depends on VCC reaching its UVLO threshold (4.5–5.5V). Since VCC derives from VIN, stable operation begins once VIN exceeds ~6.5V under typical load. Below 6V, the device remains disabled with 1μA shutdown current.

How does the MP3383GS-Z handle an open LED string during operation?

When one LED string opens, the corresponding LEDx pin voltage drops below 100mV, triggering open-string detection. The IC marks that string as inactive, continues boosting VOUT until OVP threshold is reached, then regulates output using remaining strings. If all strings open, the IC shuts down the converter entirely.

Can MP3383GS-Z drive more than four LED strings?

Yes - multiple MP3383GS-Z ICs can be cascaded using shared VIN and synchronized ISENSE connections. Each IC controls four strings, enabling scalable backlight architectures (e.g., 8, 12, or 16 strings) with consistent current matching across all channels.

What is the purpose of the ADIM pin's internal RC filter?

The ADIM pin integrates a 10MΩ resistor and 100pF capacitor to convert incoming PWM signals into a stable DC voltage proportional to duty cycle. This enables analog dimming without external filtering components, provided the PWM frequency exceeds 20kHz to avoid visible ripple in LED current.

Does MP3383GS-Z require external compensation components on the COMP pin?

Yes - the COMP pin requires external compensation (typically a series RC network from COMP to GND) to stabilize the boost converter's feedback loop. Component values depend on selected inductor, output capacitance, and desired phase margin; MPS Application Note AN043 provides design guidelines and example networks.

What happens if the EN pin is left floating?

The EN pin must not be left floating. An unconnected EN pin may cause erratic enable/disable behavior due to noise coupling. The datasheet specifies weak internal pull-down, but reliable operation requires explicit logic-level control: >1.2V to enable, <0.4V to disable, with proper decoupling near the pin.

Is the exposed pad (EP) on MP3383GS-Z electrically connected internally?

No - the exposed pad is a thermal pad only, with no internal electrical connection. It must be soldered to a GND copper pour for thermal dissipation and EMI reduction, but it is not tied to any internal node beyond mechanical mounting and thermal conduction.