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

Monolithic Power Systems Inc. MP3389EF-LF-Z

Name: MP3389EF-LF-Z
Brand: Monolithic Power Systems Inc.
SKU: MP3389EF-LF-Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP3389EF-LF-Z

Manufacturer:: Monolithic Power Systems Inc.

Category:: LED Drivers

Package:: 28-TSSOP (0.173", 4.40mm Width) Exposed Pad

Datasheet:: MP3389EF-LF-Z.pdf

Description:: IC LED DRV CTRL PWM 60MA 28TSSOP

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Product details

Overview

MP3389EF-LF-Z from Monolithic Power Systems is a 12-string, step-up white LED driver IC designed for large LCD panel backlighting. It integrates a fixed-frequency current-mode boost controller and 12 matched current sinks (±2.5% matching), supports 5V–28V input, delivers up to 60mA per string, and features programmable switching frequency (100–500kHz) and dual-mode PWM/DC dimming for precise brightness control in TV and monitor backlight systems.

For engineers reviewing the MP3389EF-LF-Z datasheet, MP3389EF-LF-Z pinout, MP3389EF-LF-Z application, or MP3389EF-LF-Z equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific use cases, and confirmed alternative parts with documented functional differences.

Technical Context

The MP3389EF-LF-Z implements a peak-current-mode, fixed-frequency boost converter with external MOSFET gate drive (GATE pin) and internal 5V LDO (VCC). Its 12 open-drain LEDX outputs each regulate current via an internal 1.22V reference at ISET, achieving 2.5% inter-string matching through dedicated current sources-not external sensing.

Dimming is implemented either by external PWM on DBRT (with BOSC tied to GND via 100kΩ) or DC voltage (0.2–1.2V) applied to DBRT, which internally generates a DPWM signal whose frequency is set by CBOSC (1.2–2kHz typical). Protection includes OVP (1.23V threshold at OVP pin), short/open LED detection via LEDX voltage monitoring, and thermal shutdown at 130°C.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	5V to 28V - powers both IC logic and external boost stage; supports wide-range DC supplies common in LCD power architectures.
LED String Count	12 strings - enables direct drive of high-resolution, edge-lit or full-array local dimming backlight topologies without external multiplexing.
Max Current per String	60mA - sufficient for driving 14+ series-connected WLEDs at typical forward voltages (3.0–3.6V), supporting >42V total string voltage.
Current Matching Accuracy	±2.5% - ensures uniform luminance across all 12 strings without per-string calibration, critical for color consistency in premium displays.
Switching Frequency Range	100kHz to 500kHz - set by ROSC resistor; higher frequencies allow smaller inductors/capacitors but increase switching loss; optimized for EMI and efficiency trade-off.
Dimming Control Modes	PWM (external 100Hz–20kHz) or DC-input (0.2–1.2V) - enables compatibility with legacy microcontroller GPIO or analog DAC dimming sources without added logic.
Regulation Reference Voltage	1.22V at ISET - defines LED current as I_LED = 1220μA / R_SET; low reference minimizes ISET resistor power loss and improves accuracy vs. temperature.
OVP Threshold	1.23V at OVP pin - triggers shutdown when output overvoltage exceeds programmed limit (e.g., due to open LED string); sets protection point via resistor divider.

Pinout & Package

MP3389EF-LF-Z is housed in a RoHS-compliant, lead-free 28-pin TSSOP package (4.4mm × 9.7mm, 0.65mm pitch), optimized for thermal performance (θ_JA = 32°C/W) in space-constrained display power modules.

Pin/Terminal	Circuit Role	Design Meaning
1, 28	NC	No-connect pins - must remain unconnected; no internal function or bonding.
2	VIN	Main power input - supplies both IC core and external boost switch; requires local ceramic bypassing for stability.
3	VCC	Internal 5V LDO output - powers gate driver and control logic; bypass to GND with ≥1μF ceramic capacitor.
4	COMP	Loop compensation node - connects RC network to GND to stabilize boost regulation feedback loop against load/transient variations.
5	EN	Enable control - active-high logic input; must be driven (not floating); initiates soft-start sequence upon assertion.
6	DBRT	Brightness control - accepts external PWM or 0.2–1.2V DC for linear dimming; polarity is positive (higher voltage = brighter).
7	GND	Analog ground reference - serves as return path for internal circuitry; separate from PGND to minimize noise coupling.
8	OSC	Oscillator frequency set - connects ROSC resistor to GND; sets f_SW = 67.85kΩ / R_OSC (kΩ) for 100–500kHz range.
9	ISET	LED current programming - regulates 1.22V across external R_SET; defines I_LED = 1220μA / R_SET per string.
10	BOSC	Dimming oscillator timing - connects CBOSC to GND to set internal DPWM frequency (1.2–2kHz); or ties to GND via 100kΩ for external PWM mode.
11–22	LED12–LED1	LED string cathode drivers - 12 open-drain outputs; sink regulated current from LED strings; tolerate up to 50V reverse voltage.
23	OVP	Over-voltage protection sense - monitors output via resistor divider; trips shutdown when voltage reaches 1.23V threshold.
24	ISENSE	Inductor current sense - inputs voltage across external R_SENSE for peak-current-mode control and cycle-by-cycle current limiting.
25	PGND	Power ground - high-current return path for boost inductor and external MOSFET; must be routed separately from AGND.
26	GATE	External N-MOSFET gate driver - high-current push-pull output (4Ω source / 2Ω sink) capable of driving >1A peak gate charge.
27	VFAULT	Fault disconnection control - drives external PMOS to isolate input from output during fault conditions (OVP, OTP, UVLO).

Key Features

Feature	Design Value
12-channel current matching	±2.5% matching between strings - eliminates need for per-string current trimming, reducing BOM cost and calibration time in mass production.
Low 550mV LED current-sink dropout	Reduces conduction loss in high-current strings - improves system efficiency by up to 3% vs. competitors with 800+mV dropout at 60mA.
Dual dimming architecture	Supports both external PWM and DC-input modes - allows reuse of existing MCU PWM peripherals or simple DAC-based dimming without firmware changes.
Integrated open/short LED protection	Automatically detects and disables faulty strings while maintaining operation of remaining strings - prevents complete backlight failure and enables graceful degradation.
Programmable OVP with 1.23V threshold	Enables precise overvoltage trip point setting (e.g., 1.2× nominal V_OUT) - avoids nuisance tripping while ensuring robust protection against open-circuit faults.
Thermal shutdown at 130°C	Prevents permanent damage during sustained overload or poor heatsinking - latches off until thermal recovery and EN reassertion.

Applications

LCD TV Backlight

Desktop Monitor Backlight

Use Scenario: Driving 12 parallel LED strings in a 55-inch 4K LCD TV with local dimming zones.

IC Role / Device Role / Timing Role: Primary step-up LED driver with integrated current regulation and fault management for high-brightness, high-uniformity backlight.

Use Value: Enables consistent luminance across 12 independently controlled zones using single-chip solution, eliminating need for discrete current regulators or external protection ICs.

Use Scenario: Powering dual-edge-lit 27-inch QHD monitor with 24 total LEDs arranged in 12 strings of 2 LEDs each.

IC Role / Device Role / Timing Role: Constant-current LED driver with programmable dimming frequency and tight current matching for flicker-free, color-accurate display operation.

Use Value: Delivers ±2.5% current matching to prevent visible brightness banding across screen, while DC-input dimming simplifies interface with monitor's microcontroller.

Flat Panel Video Display

Commercial Digital Signage

Use Scenario: Backlighting a 43-inch public information display operating 24/7 in ambient temperatures up to 70°C.

IC Role / Device Role / Timing Role: High-reliability LED driver with thermal shutdown, UVLO hysteresis, and robust OVP for continuous-duty industrial applications.

Use Value: Maintains stable LED current despite input voltage sag and temperature drift, extending LED lifetime and reducing field failure rates.

Use Scenario: Driving high-luminance backlight in outdoor-facing digital signage with variable input (12–24V DC) and EMC-sensitive environment.

IC Role / Device Role / Timing Role: Step-up controller with programmable 100–500kHz switching frequency to shift noise spectrum away from critical RF bands.

Use Value: Allows EMI filter optimization via frequency tuning, meeting CISPR-32 Class B emissions limits without oversized magnetics or shielding.

Equivalent & Alternatives

The following parts are listed as comparable options for similar 12-channel WLED driver applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
ISL97686IRZ-T7A	8-string driver with integrated MOSFETs; no external boost switch required; 3.3V–5.5V input only.	Suitable for low-voltage, compact designs where board space is constrained and input is regulated 5V.	Select when external MOSFET layout complexity must be eliminated and input voltage is stable ≤5.5V.
LM3409QMY/NOPB	Single-channel buck-boost LED controller; requires external current sense and MOSFETs; no multi-string current matching.	Used in custom multi-phase designs with independent string control and higher flexibility in topology choice.	Select when application demands per-string dimming granularity or non-standard topologies (e.g., SEPIC, flyback) beyond fixed boost.

Compared with ISL97686IRZ-T7A, MP3389EF-LF-Z supports wider input (5–28V) and higher string count (12 vs. 8) but requires external MOSFET; compared with LM3409QMY/NOPB, it delivers factory-matched current regulation across all strings-reducing system-level calibration effort and improving luminance uniformity out-of-box.

Availability

MP3389EF-LF-Z is available at Aetrix Electronics and suitable for LCD TV backlighting, desktop monitor power systems, flat-panel video displays, and commercial digital signage requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP3389EF-LF-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 expertise in DC/DC conversion, LED drivers, motor control, and battery management.

The MP3389 belongs to MPS's high-efficiency backlight driver product line, engineered specifically for large-format LCD panels requiring precise multi-string current regulation, robust fault protection, and flexible dimming in cost-sensitive consumer and commercial displays.

FAQ

What is the minimum recommended input voltage for reliable startup?

The MP3389EF-LF-Z has an input UVLO rising threshold of 3.4V to 4.3V with 200mV hysteresis. For guaranteed startup under all conditions, VIN must exceed 4.3V before enabling EN. Below this, the internal VCC regulator cannot establish stable 5V bias for gate drive and control logic, causing erratic behavior or failure to initiate soft-start.

Can MP3389EF-LF-Z drive LED strings with different forward voltages?

Yes - the device automatically selects the highest active LEDX pin voltage as the feedback reference, ensuring sufficient bus voltage for all strings. If one string has significantly higher V_F, the boost output rises to accommodate it, while remaining strings operate within their current-regulated range without overvoltage stress.

How does open-string protection behave when multiple strings fail?

When an LED string opens, its LEDX pin voltage drops below 180mV; the MP3389 marks it off and disables current regulation for that channel. Remaining strings continue operating at full current. If all 12 strings open, the device shuts down the boost converter and asserts VFAULT to disconnect input power.

What is the maximum allowable ripple on the ISET pin?

The ISET pin must be held within ±10mV of its 1.22V reference to maintain LED current accuracy. Excessive noise or ripple - caused by poor PCB layout or shared return paths - directly modulates I_LED. A 100nF ceramic capacitor from ISET to AGND is recommended to suppress high-frequency coupling.

Does MP3389EF-LF-Z support analog dimming?

No - it does not support true analog (linear) dimming. Dimming is exclusively PWM-based: either externally applied PWM to DBRT or DC voltage (0.2–1.2V) converted internally to DPWM. The DC input provides linear duty-cycle mapping but still results in pulsed LED current, preserving efficiency and avoiding color shift.

What thermal derating applies above 25°C ambient?

With θ_JA = 32°C/W in TSSOP28, junction temperature rise is ΔT_J = P_D × 32. At 125°C max TJ and 25°C TA, max allowed power dissipation is 3.125W. Above 25°C, allowable PD decreases linearly: e.g., at 70°C TA, max PD = (125–70)/32 ≈ 1.72W - requiring careful layout and airflow in high-temp environments.

Is the VFAULT pin actively driven or open-drain?

VFAULT is a push-pull output capable of sourcing and sinking current. During normal startup, it ramps up to slowly turn on an external PMOS for inrush control. During fault conditions (OVP, OTP, UVLO), it pulls low to turn off the PMOS and isolate VIN from VOUT - providing active, bidirectional control of input disconnection.

MP3389EF-LF-Z Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: 28-TSSOP (0.173", 4.40mm Width) Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: DC DC Controller

Topology:: Step-Up (Boost)

Internal Switch(s):: No

Number of Outputs:: 12

Voltage - Supply (Min):: 5V

Voltage - Supply (Max):: 28V

Voltage - Output:: -

Current - Output / Channel:: 60mA

Frequency:: -

Dimming:: PWM

Applications:: Backlight

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 28-TSSOP-EP

MP3389EF-LF-Z FAQ

1.How can I place an order for MP3389EF-LF-Z through Aetrix?

Please submit a Request for Quotation (RFQ) for MP3389EF-LF-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 MP3389EF-LF-Z reliable?

The price and inventory of MP3389EF-LF-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP3389EF-LF-Z is usually 5 days.

3.What payment methods are accepted for MP3389EF-LF-Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP3389EF-LF-Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP3389EF-LF-Z?

MP3389EF-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP3389EF-LF-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 MP3389EF-LF-Z?

For technical support, including MP3389EF-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP3389EF-LF-Z requirements.

6.How does Aetrix verify that MP3389EF-LF-Z is sourced from the original manufacturer or authorized distributors?

All MP3389EF-LF-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 MP3389EF-LF-Z meets industry standards.

7.What is the process for return or replacement of MP3389EF-LF-Z?

All MP3389EF-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP3389EF-LF-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 MP3389EF-LF-Z part is unused and in its original packaging.

Return procedure for MP3389EF-LF-Z:

1.Submit a request within 90 days.

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

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