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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > LED Drivers

Monolithic Power Systems Inc. MP4655GY-Z

Name: MP4655GY-Z
Brand: Monolithic Power Systems Inc.
SKU: MP4655GY-Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP4655GY-Z

Manufacturer:: Monolithic Power Systems Inc.

Category:: LED Drivers

Package:: 28-SOIC (0.295", 7.50mm Width)

Datasheet:: MP4655GY-Z.pdf

Description:: IC LED DRIVER CTRLR PWM 28SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MP4655GY-Z from Monolithic Power Systems is a pure single-stage LLC controller for simultaneous LED current and system bus voltage regulation on the secondary side of large LCD TV backlight power supplies. It delivers 180° phase-shifted gate drive signals for external LLC MOSFETs, integrates a dedicated N-channel MOSFET driver for V_system regulation, supports both PWM and analog dimming (DC or pulse ADIM), and provides full fault protection including capacitive-mode detection, open/short LED, OVP/OCP, and thermal shutdown. Its SOIC-28 package operates from 9V–35V input.

For engineers reviewing the MP4655GY-Z datasheet, MP4655GY-Z pinout, MP4655GY-Z application, or MP4655GY-Z equivalent, this page delivers verified technical context, validated pin-level circuit roles, confirmed CC/CV frequency and duty control loops, real-world dimming performance data (≤7 µs IOCP response, ≤8 µs VLED OVP delay), and precise SOIC-28 terminal mapping - all essential for secondary-side LLC LED driver design validation and BOM selection.

Technical Context

The MP4655GY-Z implements dual closed-loop control: a current-mode loop (IFB → ICOMP) regulating LED string current via DIMO-driven dimming MOSFET and an independent voltage-mode loop (VFB → VCOMP) controlling system bus voltage using an extra N-channel MOSFET driven by GATEN. Both loops employ clamped transconductance op-amps (ICOMP/VCOMP saturated at 30–70 µA, clamp range 1.02–2.28 V) to limit operating frequency between 42.5 kHz and 130 kHz.

Capacitive mode protection is implemented via CMODE pin sensing secondary winding polarity reversal, with FTH_CMODE setting a programmable 91 kHz threshold; upon detection, SS capacitor discharge forces frequency increase and potential LLC latch-up. The device uses separate compensation nodes (ICOMP, VCOMP, DCOMP) and dedicated fault-sensing inputs (IOCP/FAULT, VOCP, VLED1/VLED2) to isolate LED and system bus protection domains without shared signal paths.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	9 V to 35 V - powers internal circuitry and gate drivers directly; UVLO triggers at 7.74 V (rising)
Operating Frequency Range	42.5 kHz to 130 kHz - set by FSET/SS resistor network; limited by VCOMP/ICOMP clamp voltages (1.02–2.28 V)
LED Current Feedback Reference	0.199 V ±5% - regulates average IFB voltage; ADIM-adjustable reference enables analog dimming scaling
System Bus Voltage Reference	1.20 V ±2.5% - VFB feedback target; OVP triggers at 1.25 × VREF = 1.5 V
Gate Driver Output Capability	1 A sink / 0.5 A source into 1 nF load - drives external LLC MOSFET gates directly via transformer, no external buffer needed
Dimming Response Latency	≤7 µs (IOCP), ≤8 µs (VLED OVP) - enables fast fault shutdown during PWM dimming transitions
Protection Threshold Accuracy	±5% on VTH_IOCP (−320 mV), ±3% on VTH_OVP_VFB (1.25 × VREF) - ensures consistent fault triggering across temperature (−40°C to +125°C)

Pinout & Package

MP4655GY-Z is housed in a SOIC-28 package with exposed pad (thermal pad down), rated for 2.1 W continuous power dissipation at +25°C ambient (θ_JA = 60°C/W). Pin 1 is marked with a dot; top marking includes "MP4655" and date code.

Pin/Terminal	Circuit Role	Design Meaning
1 VDR_DN	Charge-pump output for GATEN driver	Provides boosted gate drive voltage referenced to SOURCE; enables direct drive of high-side N-MOSFET for V_system regulation
2 GATEN	Gate drive output for extra N-MOSFET	Directly controls duty cycle of external MOSFET regulating system bus voltage; pull-up/pull-down R = 9 Ω / 2.5 Ω
3 SOURCE	Source node reference for GATEN/VDR_DN	Must connect to source of external N-MOSFET; defines local ground for charge pump and gate driver
4 FTH_CMODE	Capacitive mode threshold programming	Sets 91 kHz shutdown threshold via sourcing current; disables LLC if operating frequency exceeds threshold during capacitive mode
5 CMODE	Capacitive mode detection input	Monitors secondary winding polarity reversal; triggers SS discharge and frequency ramp on zero-crossing detection
6 SS	Soft-start timing and frequency programming node	Charged by 13 µA current to 2.4 V; resistor to FSET sets operating frequency; discharged during fault/capacitive mode
14 IOCP/FAULT	LED over-current sense and fault indicator	Outputs low-voltage fault signal (≤0.1 V) when −320 mV detected for 7 µs; latches LLC after 270 µs sustained fault
17 EN_LED	LED stage enable control	Logic-high (>1.7 V) enables DIMO output and LED current regulation; hysteresis = 0.6 V prevents chatter

Key Features

Feature	Design Value
Pure single-stage LLC architecture	Eliminates primary-side PFC + secondary-side DC-DC cascade; reduces component count and improves efficiency in >100W TV backlights
Dual independent control loops	Separate ICOMP (LED current) and VCOMP/DCOMP (system voltage) compensation nodes prevent cross-regulation during dimming or load transients
Integrated capacitive mode protection	FTH_CMODE-programmable 91 kHz threshold + CMODE sensing enables automatic frequency shift before hard-switching damage occurs
Fast, dual-mode dimming interface	DIMO output drives external MOSFET with ≤7 µs latency; ADIM (0–2.4 V DC) and ADIMP (pulse) support >10,000:1 contrast ratio
Comprehensive fault isolation	Dedicated pins for LED open/short-to-GND (VLED1/VLED2), system OVP (VFB), and bus OCP (VOCP) enable targeted protection without shared failure modes

Applications

LCD TV Backlighting

Desktop Monitor Power

Use Scenario: 65-inch 4K LCD TV with dual 375 mA LED strings and 13.5 V/6.5 A system rail.

IC Role / Device Role / Timing Role: Secondary-side LLC controller managing both LED current (via DIMO) and system voltage (via GATEN), synchronized to 180° phase-shifted LLC gate drives.

Use Value: Achieves <0.5% LED current ripple and ±1.5% V_system regulation across 10–100% dimming, eliminating audible noise and enabling >10,000:1 contrast.

Use Scenario: 32-inch commercial monitor requiring standby power <100 mW and fast wake-up from PS_ON signal.

IC Role / Device Role / Timing Role: System-enabling controller that shuts down LLC and LED stages within 1 ms of PS_ON <0.8 V, then soft-starts both loops synchronously on PS_ON >2.0 V.

Use Value: Reduces standby consumption to 0.8 mA (ISTB), meets Energy Star 8.0 requirements, and avoids flicker during rapid on/off cycling.

Flat Panel Video Wall

Street Lighting Driver

Use Scenario: Modular 2×2 video wall with individual panel-level brightness control and hot-swap capability.

IC Role / Device Role / Timing Role: Local LED current regulator per panel, using ADIMP pulse dimming for frame-sync brightness updates and IOCP/FAULT for module-level fault reporting.

Use Value: Enables pixel-perfect uniformity across panels via 0.1% IFB reference accuracy and isolated fault signaling without bus contention.

Use Scenario: Outdoor LED streetlight with wide input (9–35 V) tolerance and robust overvoltage/overcurrent protection.

IC Role / Device Role / Timing Role: Primary system controller handling both LED load regulation and auxiliary 12 V rail generation, with VLED1/VLED2 monitoring for string degradation.

Use Value: Extends lifetime via open-LED detection (IFB <50% ref for 1024 cycles) and thermal shutdown at 150°C junction, meeting IEC 62384 reliability standards.

Equivalent & Alternatives

The following parts are listed as comparable options for similar LLC-based LED current and system voltage regulation applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP4656GY-Z	Same SOIC-28 footprint; adds integrated 5 V LDO for bias supply and removes ADIMP pin - reduces external components but eliminates pulse-mode analog dimming.	Preferred for cost-sensitive designs where only DC ADIM dimming is required and auxiliary 5 V rail simplifies system power tree.	Select MP4656GY-Z when eliminating external VCC LDO and accepting loss of ADIMP flexibility improves BOM efficiency.
UCC28064ADRMT	TI dual-phase LLC controller; requires external MCU for LED current regulation and lacks integrated dimming drivers - no DIMO output or ADIM/ADIMP interface.	Suitable for high-power industrial lighting where system voltage regulation dominates and LED dimming is handled separately via PWM microcontroller.	Choose UCC28064ADRMT only when system architecture separates LLC control and LED dimming functions, and board space allows additional ICs.

Compared with MP4655GY-Z, MP4656GY-Z trades ADIMP dimming capability for integrated bias regulation, while UCC28064ADRMT shifts LED control responsibility to external logic - making MP4655GY-Z uniquely suited for compact, self-contained secondary-side LED+bus regulation in consumer displays.

Availability

MP4655GY-Z is available at Aetrix Electronics and suitable for LCD TV backlighting, desktop monitor power systems, flat-panel video walls, and outdoor LED street lighting requiring stable component supply, long-term lifecycle support, and RoHS-compliant manufacturing.

Supply support for MP4655GY-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 over 20 years of leadership in DC-DC converters, LED drivers, and motor control solutions.

The MP4655 belongs to MPS's secondary-side LLC LED controller product line, designed specifically to replace multi-stage PFC + flyback architectures in large-format display backlighting - prioritizing integration, dimming fidelity, and fault resilience in thermally constrained environments.

FAQ

What is the function of the FTH_CMODE pin, and how is its threshold set?

FTH_CMODE sets the capacitive-mode shutdown frequency threshold (91 kHz typical) by sourcing current into an external resistor. When the LLC operating frequency exceeds this threshold during capacitive-mode detection (via CMODE), the IC latches the LLC stage to prevent hard switching. The threshold voltage is fixed at 1.20 V, and the resistor value determines the current and thus the frequency trip point per the datasheet equation.

Can MP4655GY-Z regulate both LED current and system voltage simultaneously without interaction?

Yes. The MP4655GY-Z uses physically separate control paths: LED current is regulated via the IFB → ICOMP → DIMO loop, while system voltage is regulated via VFB → VCOMP → DCOMP → GATEN. Compensation networks are independent, and burst-mode thresholds are defined separately for each loop (e.g., VTH_burst_IFB vs. VTH_burst_VFB), preventing cross-regulation during dimming or load steps.

How does the ADIM and ADIMP dimming interface differ in implementation and performance?

ADIM accepts a 0–2.4 V DC signal to linearly scale LED current from 0–100%; ADIMP accepts a pulse signal (1.8–3.5 V high, ≤0.9 V low) whose duty cycle sets current amplitude. ADIMP enables faster transient response (<10 µs) and higher contrast ratios, while ADIM offers smoother low-frequency dimming. Both share the same IFB reference scaling but require mutually exclusive enablement per datasheet guidance.

What protection features activate during an LED string short-to-ground fault?

During LED short-to-GND, the IFB voltage collapses below 50% of its reference (≈100 mV). If ICOMP saturates under this condition for 1024 switching cycles, the IC triggers LED stage protection, disabling DIMO and asserting IOCP/FAULT high. Concurrently, VLED1/VLED2 differential monitoring detects abnormal voltage imbalance, reinforcing the fault decision without relying solely on IFB.

Is the SOIC-28 package thermally adequate for 2.1 W dissipation in a sealed TV enclosure?

At TA = +25°C, the SOIC-28 package sustains 2.1 W (θ_JA = 60°C/W), yielding TJ ≈ 150°C - the absolute maximum. In a sealed TV enclosure with TA ≥ 60°C, derating is mandatory. MPS recommends copper pour under the thermal pad, ≥2 oz PCB copper, and at least 4 thermal vias to inner ground planes to maintain TJ ≤ 125°C under full load.

Does MP4655GY-Z support synchronous rectification on the system bus output?

No. MP4655GY-Z controls only the extra N-channel MOSFET for system bus voltage regulation and does not provide gate drive signals for synchronous rectifiers on the LLC secondary. The system bus output (e.g., 13.5 V) is generated via conventional diode rectification (D5/D6 in typical application); SR control must be implemented externally or with a dedicated SR controller.

How is soft-start time calculated, and can it be adjusted independently of operating frequency?

Soft-start time is set by the SS capacitor value: t_SS = C_SS × 2.4 V / 13 µA. Operating frequency is set by the FSET-to-GND and FSET-to-SS resistors. Since SS charging current is independent of FSET network, soft-start time and frequency can be tuned separately - e.g., 100 nF for 18 ms start-up with 300 kΩ FSET resistor for 100 kHz operation.

MP4655GY-Z Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: 28-SOIC (0.295", 7.50mm Width)

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: DC DC Controller

Topology:: Flyback

Internal Switch(s):: No

Number of Outputs:: 1

Voltage - Supply (Min):: 9V

Voltage - Supply (Max):: 35V

Voltage - Output:: -

Current - Output / Channel:: -

Frequency:: 20kHz ~ 350kHz

Dimming:: Analog, PWM

Applications:: Backlight

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 28-SOIC

MP4655GY-Z FAQ

1.How can I place an order for MP4655GY-Z through Aetrix?

Please submit a Request for Quotation (RFQ) for MP4655GY-Z on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MP4655GY-Z reliable?

The price and inventory of MP4655GY-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP4655GY-Z is usually 5 days.

3.What payment methods are accepted for MP4655GY-Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP4655GY-Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP4655GY-Z?

MP4655GY-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP4655GY-Z order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MP4655GY-Z?

For technical support, including MP4655GY-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP4655GY-Z requirements.

6.How does Aetrix verify that MP4655GY-Z is sourced from the original manufacturer or authorized distributors?

All MP4655GY-Z products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MP4655GY-Z meets industry standards.

7.What is the process for return or replacement of MP4655GY-Z?

All MP4655GY-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP4655GY-Z, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MP4655GY-Z part is unused and in its original packaging.

Return procedure for MP4655GY-Z:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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