Monolithic Power Systems Inc. MP3021DQ-LF-Z

Overview

MP3021DQ-LF-Z from Monolithic Power Systems is a 1×/1.5×/2× auto-adjust charge pump white LED backlight driver IC supporting up to four 30 mA WLEDs in common-anode configuration. It integrates single-wire MPC™ serial control, thermal shutdown, under-voltage protection, and soft-start. Designed for compact portable displays, it operates from 2.7 V to 5.5 V input and delivers >90% efficiency at 4.2 V with 30 mA per LED.

For engineers reviewing the MP3021DQ-LF-Z datasheet, MP3021DQ-LF-Z pinout, MP3021DQ-LF-Z application, or MP3021DQ-LF-Z equivalent, key selection criteria include its 5-bit + LC-bit brightness control (32 levels + fine low-current mode), ±3% LED current matching at 20 mA, QFN16 (3 mm × 3 mm) package with exposed thermal pad, and MPC™ protocol timing compliance (1.5–3.5 µs data pulse width).

Technical Context

The MP3021DQ-LF-Z implements a fully integrated switched-capacitor charge pump with automatic gain selection (1×, 1.5×, or 2×) based on input voltage and LED forward voltage, enabling high-efficiency operation across 2.7–5.5 V battery ranges. Its internal 1.2 MHz oscillator drives charge pump switching without external inductors.

Control is executed via a unidirectional single-wire MPC™ interface: data pulses encode enable/disable, LED selection (1–4 LEDs), HC/LC mode, and 5-bit brightness level. The ISET pin sets full-scale current using a precision 1.25 V reference and 100× current gain, supporting 2–30 mA per LED with resistor-programmable scaling.

Key Specifications

Pinout & Package

MP3021DQ-LF-Z is housed in a thermally enhanced 3 mm × 3 mm QFN-16 package with exposed thermal pad (connected to Pin 5/VSS). The package supports reflow soldering per JEDEC MO-220 VEED-4 and features 0.5 mm pitch leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP3021DQ-LF-Z, MP1519DJ-LF-Z offers measurable gains in efficiency and standby current while maintaining backward compatibility, whereas RT9397BZSP trades protocol simplicity and dimming precision for standardized I²C integration at lower peak current capability.

Availability

MP3021DQ-LF-Z is available at Aetrix Electronics and suitable for cellular phones, PDA phones, and portable media players requiring stable component supply and legacy design support.

Supply support for MP3021DQ-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 core expertise in DC/DC conversion, LED drivers, and motor control.

The MP3021 belongs to MPS's WLED backlight driver product line, engineered specifically for space-constrained portable electronics requiring high-efficiency, low-EMI, and minimal external component count.

FAQ

What is the function of the CP pin, and why must it not be driven externally?

The CP pin is the internal charge pump switching node, directly connected to flying capacitors C1 and C2. Driving it externally risks damaging internal switches or causing uncontrolled charge redistribution. Its voltage swings between VIN and ~2×VIN depending on mode; the datasheet explicitly prohibits external forcing to avoid latch-up or efficiency collapse.

How does the HC/LC bit affect brightness control resolution and minimum current?

The HC/LC bit selects between high-current (HC) and low-current (LC) scaling modes. In LC mode, the 5-bit brightness code maps to 0.09–3.00 mA (step ≈ 0.09 mA), enabling precise sub-mA dimming. In HC mode, the same code maps to 0.94–30.00 mA (step ≈ 0.94 mA), optimizing dynamic range for full-brightness operation.

Can MP3021DQ-LF-Z drive LEDs in common-cathode configuration?

No. MP3021DQ-LF-Z is designed exclusively for common-anode WLED topologies: its LED0–LED3 pins are constant-current sinks that connect to LED cathodes, requiring the anodes to be tied to the battery rail. Common-cathode configurations would require sourcing current, which this device does not support.

What is the maximum total output current, and how is it distributed across channels?

The MP3021DQ-LF-Z supports up to 30 mA per channel across four independent outputs (LED0–LED3), yielding a maximum total output current of 120 mA. Current is strictly regulated per channel; no shared current-sense or cross-regulation occurs - each output maintains its programmed value regardless of adjacent channel loading.

Why does the datasheet state "NOT RECOMMENDED FOR NEW DESIGNS"?

This designation reflects Monolithic Power Systems' official recommendation to adopt the MP1519 - a direct successor with enhanced specs (higher efficiency, lower shutdown current, wider VIN) and identical pinout/package. MP3021DQ-LF-Z remains fully supported for existing designs but is not promoted for new schematics due to the superior performance and longevity roadmap of the MP1519 family.

What external components are mandatory, and what values are recommended?

Mandatory components are: (1) Two 1 µF X5R/X7R ceramic flying capacitors (C1, C2) connected to C1A/C1B/C2A/C2B; (2) One 1 µF input bypass capacitor from VIN to VSS; (3) One pull-down resistor (100 kΩ) on the DATA line; (4) One ISET resistor (e.g., 4.17 kΩ for 30 mA full scale). All capacitors must be placed within 2 mm of their respective pins.