Monolithic Power Systems Inc. MP3326GR-P

Overview

MP3326GR-P from Monolithic Power Systems is a 16-channel WLED driver IC with integrated current sinks, I²C interface, and independent PWM + analog dimming per channel. It operates from 4V to 16V input, delivers up to 50mA per channel (VIN ≥ 4.5V), supports 12-bit PWM and 6-bit analog dimming, and integrates open-load, short-circuit, and over-temperature protection. It targets high-channel-count LED backlighting in automotive instrument clusters.

For engineers reviewing the MP3326GR-P datasheet, MP3326GR-P pinout, MP3326GR-P application, or MP3326GR-P equivalent, key selection criteria include per-channel dimming independence, I²C address configurability (10 options via resistor), RFSH/FLT dual-mode pin (refresh signal or fault flag), LED current slew rate control (5–20 µs), and phase-shifted PWM timing (40 µs inter-channel delay) for EMI reduction.

Technical Context

The MP3326GR-P implements a fully integrated linear LED driver architecture with 16 matched current sinks, each independently controllable via I²C registers. Its dual-dimming engine allows simultaneous 12-bit PWM (220–330 Hz selectable) and 6-bit analog current scaling per channel - enabling precise grayscale and brightness control without external DACs or PWM generators.

Protection logic is register-configurable: short-circuit threshold (2–5 V), latch/hiccup fault response mode, and thermal shutdown at 170°C with 20°C hysteresis. The RFSH/FLT pin functions as either a synchronized LCD refresh signal (programmable 0–315 Hz) or an active-low fault indicator, selected by FLTEN bit - eliminating need for external fault monitoring circuitry.

Key Specifications

Pinout & Package

MP3326GR-P is housed in a thermally enhanced QFN-24 package (4 mm × 4 mm, 0.5 mm pitch) with exposed thermal pad for PCB heat dissipation. Pin 14 is GND; pin 24 is VIN; pins 7–23 are dedicated LED cathode current sinks (LED1–LED16); pin 6 sets full-scale current via external resistor.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS31FL3728-QFLS4 and TPS61196RTVR, MP3326GR-P uniquely combines linear architecture (no inductor), dual-dimming resolution, programmable refresh output, and automotive-grade protection - making it optimal for cost-sensitive, EMI-sensitive, and thermally demanding instrument cluster designs.

Availability

MP3326GR-P is available at Aetrix Electronics and suitable for automotive instrument clusters, RGB status indicators, general-purpose LED backlighting, and smart display control panels requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MP3326GR-P 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 power management ICs, including DC/DC converters, LED drivers, motor drivers, and battery management solutions.

The MP3326 product line is designed specifically for high-channel-count, high-fidelity LED lighting in automotive and industrial human-machine interfaces - emphasizing integration, thermal robustness, and EMI control without external components.

FAQ

What is the minimum input voltage required for full 50 mA/channel operation?

The MP3326GR-P delivers its rated 50 mA per channel only when VIN ≥ 4.5 V, as specified in the Electrical Characteristics table. Below this, current capability degrades due to reduced headroom across the internal current sinks; at VIN = 4.0 V, maximum current drops to approximately 40 mA/channel under typical conditions.

How does the RFSH/FLT pin behave when FLTEN = 0 versus FLTEN = 1?

When FLTEN = 0, RFSH/FLT outputs a clean square-wave refresh signal (frequency set by FRFSH[9:0]) regardless of fault status. When FLTEN = 1, the pin becomes an active-low open-drain fault flag: pulled low during any protection event (open-load, short, OTP, UVLO), and returns high only after fault bits are read and condition clears.

Can multiple MP3326GR-P ICs share the same I²C bus without address conflict?

Yes - each MP3326GR-P supports 10 unique I²C addresses (0x30–0x39) configured via external resistor on the ADDR pin. This allows up to 10 devices on one bus. Address selection is hardware-based and stable across power cycles; no software address assignment is needed.

What is the purpose of the 40 µs phase shift feature, and how is it enabled?

The 40 µs phase shift staggers PWM rising edges across consecutive LED channels (e.g., LED2 starts 40 µs after LED1), reducing peak input current and system-level EMI. It is enabled by setting PS_EN = 1 in Register 0x01; no additional timing components or host intervention is required once activated.

Does the MP3326GR-P support both hiccup-mode and latch-off fault recovery?

Yes - the LATCH bit (Register 0x01, bit 6) selects fault behavior: LATCH = 0 enables hiccup mode (automatic retry every 1 ms), while LATCH = 1 enables latch-off mode (requires VIN or EN reset to clear fault). Both modes assert the RFSH/FLT pin low and set corresponding fault register bits.

How is LED current accuracy affected by the external ISET resistor tolerance?

LED current scales linearly with ISET resistor value; a ±1% resistor yields ±1% nominal current error. Channel-to-channel matching remains within ±2% (typ) regardless of resistor tolerance, as internal current sources are trimmed and matched during wafer test - critical for uniform display brightness.

What thermal derating applies above 25°C ambient temperature?

With θJA = 42°C/W on a 4-layer PCB, power dissipation must be reduced by 23.8 mW/°C above 25°C to maintain TJ ≤ 150°C. At TA = 85°C, max continuous power drops to ~1.5 W - requiring careful layout (thermal pad soldering, copper pour) and possibly reduced channel count or current in high-temp enclosures.