Monolithic Power Systems Inc. EV1528DQ-00A

Overview

EV1528DQ-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MP1528DQ white LED driver IC, designed to drive up to nine series-connected WLEDs from a single-cell Li-ion battery (2.7–5.5 V), delivering precise 20 mA LED current with analog/PWM brightness control via the BRT pin and overvoltage protection via the BIAS pin.

For engineers reviewing the EV1528DQ-00A datasheet, EV1528DQ-00A pinout, EV1528DQ-00A application, or EV1528DQ-00A equivalent, this board enables rapid validation of WLED backlighting performance in compact portable displays, including brightness linearity, efficiency across input voltage range (3.0 V to 4.2 V), and open-circuit fault response under real-world load conditions.

Technical Context

The EV1528DQ-00A implements the MP1528DQ - a current-mode, variable-frequency boost converter optimized for WLED driving - with external current sensing (R1 = 20 Ω sets nominal 20 mA), BIAS-based overvoltage shutdown (triggered above ~19 V), and dual-mode dimming: analog control (0.3–1.2 V on BRT) and PWM (100–400 Hz, logic-level swing).

Board-level design integrates all critical passives: 4.7 µF/10 V input capacitor (C1), 1 µF/50 V feedback capacitor (C2), 10 nF bypass (C3), 6.2 µH power inductor (L1), and Schottky diode (D1, B160B-13-F), supporting stable operation across 7–9 LED strings at up to 5.5 V input.

Key Specifications

Availability

EV1528DQ-00A is available at Aetrix Electronics and suitable for handheld computers, PDA phones, digital cameras, and small LCD display backlight development requiring stable component supply, pre-validated reference design, and fast-turn prototyping support.

Supply support for EV1528DQ-00A 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 MP1528 product line delivers highly integrated, thermally robust WLED drivers for space-constrained portable applications, emphasizing low quiescent current, high efficiency across battery voltage range, and reliable fault protection.

FAQ

What is the purpose of the BIAS pin on the EV1528DQ-00A board?

The BIAS pin monitors output voltage and disables the MP1528DQ's power switch when voltage exceeds ~19 V, protecting against overvoltage faults such as open LED strings or excessive LED count. It connects directly to the LED cathode node and requires no external components for basic OVP functionality.

How do I adjust LED current on the EV1528DQ-00A?

LED current is set by the value of R1 (20 Ω by default). Replace R1 with a precision resistor: I_LED ≈ 8 mV / R1. For example, a 16 Ω resistor yields ~25 mA. Ensure R1 tolerance is ≤1% and power rating ≥0.125 W to maintain regulation accuracy.

Can the EV1528DQ-00A drive fewer than 7 LEDs?

No - the MP1528DQ is specified for 7–9 series WLEDs only. Driving fewer LEDs risks exceeding the 19 V OVP threshold during startup or dimming transients, causing unintended shutdown. Minimum forward voltage must be ≥14 V (7 × ~2 V) to ensure stable regulation.

What is the recommended PWM frequency range for brightness control?

The BRT pin accepts PWM signals from 100 Hz to 400 Hz. Frequencies below 100 Hz cause visible flicker; above 400 Hz reduce dimming resolution due to limited internal comparator response. Duty cycle linearly controls average LED current between 0% and 100%.

Is the EV1528DQ-00A RoHS compliant and lead-free?

Yes - all components on the EV1528DQ-00A board, including the MP1528DQ QFN6 IC, TDK capacitors, Toko inductor, and Diodes Inc. Schottky diode, are RoHS-compliant and lead-free per MPS documentation Rev. 1.0 (October 2007) and manufacturer part specifications.

Does the board include populated LEDs?

No - LED1 through LED9 positions are "Not Stuffed" per the Bill of Materials. Users must solder their own white LEDs matching the forward voltage and thermal requirements of their target display, enabling customization for specific luminance and color point needs.