Monolithic Power Systems Inc. MP4700GS-Z

Overview

MP4700GS-Z from Monolithic Power Systems is a high-efficiency, boundary conduction mode (BCM), low-side buck white LED driver IC that regulates constant LED current via external MOSFET control. It operates from 8V–18V input, features 302mV CS reference voltage, 160kHz max switching frequency, and PWM dimming support for precise brightness control in TV backlighting and industrial lighting systems.

For engineers reviewing the MP4700GS-Z datasheet, MP4700GS-Z pinout, MP4700GS-Z application, or MP4700GS-Z equivalent, this device delivers zero-current turn-on, hiccup short-circuit protection, bus-input UVLO, thermal shutdown, and low 1mA quiescent current-key selection criteria for high-reliability LED driver designs requiring stable current regulation and EMI-optimized operation.

Technical Context

The MP4700GS-Z implements peak-current-controlled BCM operation using valley-voltage detection at the DRV pin to enable soft-switching of the external MOSFET, eliminating freewheeling diode reverse recovery loss and minimizing inductor size. Its internal LDO supplies VCC at 8.4V (VIN < 12V) or switch-controlled current source mode (VIN > 12V), maintaining regulated logic and gate drive power across input range.

Current regulation relies on sensing MOSFET peak current through an external resistor at the CS pin, with a tightly specified 285–315mV reference at +25°C. Protection includes dual UVLO (VCC and bus input), 150°C thermal shutdown with 30°C hysteresis, and 2.8ms hiccup-mode response to output short conditions.

Key Specifications

Pinout & Package

MP4700GS-Z is housed in an SOIC8 package (5.0mm × 6.2mm, 1.27mm pitch) with exposed pad for thermal enhancement. Pin 1 marked with notch or dot; standard JEDEC SOIC footprint with recommended land pattern per MPS documentation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar constant-current LED driver applications.

Compared with MP4700GS-Z, MPQ4425HG-AEC1 trades external MOSFET flexibility and 280V bus compatibility for automotive qualification and integration, while LM3409HV offers broader topology support at the cost of added external components for UVLO and current sensing calibration.

Availability

MP4700GS-Z is available at Aetrix Electronics and suitable for TV backlighting, industrial LED lighting, automotive interior lighting, and DC/DC LED driver modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for MP4700GS-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 MP4700 product line is designed specifically for high-efficiency, high-voltage LED driver applications requiring boundary conduction mode operation, integrated protection, and simplified system-level design in TV, industrial, and automotive lighting.

FAQ

What is the recommended inductor value for MP4700GS-Z in a 280V bus, 210V LED application?

For a 280V bus and 210V LED string with 250mA current, the minimum inductance is 1.1mH to keep switching frequency ≤150kHz under worst-case conditions. An off-the-shelf 1.3mH/0.6A shielded inductor meets peak current (500mA) and RMS (0.27A) requirements while ensuring stable BCM operation.

Can MP4700GS-Z operate without PWM dimming control?

Yes. Leaving the PWM pin open or applying a logic-high voltage (≥1.5V) disables PWM dimming and enables continuous LED current regulation. The IC remains fully functional for constant-brightness applications such as industrial task lighting or signage.

How does the INUV pin interface with a 280V DC bus?

The INUV pin senses bus voltage via a resistor divider (e.g., 150kΩ + 91kΩ) to scale 280V down to ~1.2V at the pin. This sets UVLO activation at ~280V × (91k / (150k + 91k)) ≈ 107V - well above typical LED string voltage, ensuring reliable start-up before load engagement.

What is the purpose of the TST pin, and how should it be connected?

The TST pin is a factory test function and must be connected directly to GND in all production designs. Leaving it floating or connecting to other nodes may cause undefined behavior or failure to start, as confirmed in the MP4700 Rev. 1.0 datasheet Section 4 "PIN FUNCTIONS".

Does MP4700GS-Z require an external bootstrap capacitor?

No. MP4700GS-Z uses a direct low-side gate drive architecture with internal VCC regulation and no high-side driver stage, eliminating the need for a bootstrap capacitor. The DRV pin drives the MOSFET source-connected gate directly from the VCC rail.

How is LED current accuracy affected by temperature?

The CS reference voltage varies from 270mV to 330mV over –40°C to +85°C, resulting in ±10% LED current drift. For tighter regulation, use a precision sense resistor with low TCR and consider closed-loop feedback in critical applications.

What layout practices prevent noise coupling into the CS pin?

Place the current sense resistor within 2mm of the CS and GND pins; route CS and GND traces as a tight, shielded pair; avoid routing near switching nodes (DRV, VIN, or inductor); and use separate analog ground pour isolated from power ground per MPS layout guidelines.