Monolithic Power Systems Inc. MPQ3326BGRE-AEC1-P

Overview

MPQ3326BGRE-AEC1-P from Monolithic Power Systems is a 16-channel AEC-Q100 Grade 1 LED driver IC for automotive lighting and instrument clusters, delivering up to 80mA per channel with independent 12-bit PWM and 6-bit analog dimming, I²C address configurability (10 options), and integrated LED open/short/thermal protection.

For engineers reviewing the MPQ3326BGRE-AEC1-P datasheet, MPQ3326BGRE-AEC1-P pinout, MPQ3326BGRE-AEC1-P application, or MPQ3326BGRE-AEC1-P equivalent, this device supports high-reliability automotive backlighting with synchronized refresh output, configurable slew rate (5–20μs), 40μs inter-channel phase shift, and fault-indicating RFSH/FLT pin behavior under UVLO, OTP, or string fault conditions.

Technical Context

The MPQ3326B integrates sixteen matched current sinks with external ISET resistor programming, supporting 16 parallel LED strings with independent per-channel dimming control via dual-register architecture: 6-bit ICHx for analog amplitude scaling and 12-bit PWMx for duty-cycle modulation. Its I²C interface uses ADDR pin voltage division to select one of ten addresses (0x30–0x39) without requiring external pull-ups on SDA/SCL.

Protection logic operates autonomously: LED open detection triggers after 4ms at VLEDx < 100mV; LED short detection activates when VLEDx exceeds programmable thresholds (2V/3V/4V/5V) for 4ms; thermal shutdown engages at 170°C with 20°C hysteresis. The RFSH/FLT pin serves dual mode-refresh signal generator (fREFRESH = 127500 × fPWM / FRFSH) or active-low fault flag-controlled by FLTEN bit.

Key Specifications

Pinout & Package

MPQ3326BGRE-AEC1-P is housed in a wettable flank QFN-24 package (4mm × 4mm, 0.5mm pitch), optimized for automated optical inspection (AOI) and solder joint reliability in automotive applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS31FL3729-QFLS4-TR and TLC5947RTQT, MPQ3326BGRE-AEC1-P uniquely combines AEC-Q100 Grade 1 compliance, dual-mode dimming, programmable refresh output, and comprehensive fault reporting in a wettable flank package-making it the sole option for functional-safety-aware automotive backlighting.

Availability

MPQ3326BGRE-AEC1-P is available at Aetrix Electronics and suitable for automotive instrument clusters, center stack displays, and exterior lighting systems requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MPQ3326BGRE-AEC1-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) designs high-performance power management semiconductors for automotive, industrial, and consumer markets, emphasizing integration, efficiency, and reliability.

The MPQ3326B belongs to MPS's AEC-Q100-qualified LED driver product line, engineered specifically for automotive cabin lighting and display backlighting where precise dimming control, fault resilience, and EMI reduction are critical.

FAQ

What is the maximum number of MPQ3326BGRE-AEC1-P devices that can be cascaded on a single I²C bus?

Up to 10 MPQ3326BGRE-AEC1-P devices can share one I²C bus using unique addresses set via the ADDR pin resistor ratio. Each device supports one of ten addresses (0x30–0x39), determined by RADDR/RISET voltage division per Table 5 in the datasheet. No external address jumpers or DIP switches are required.

How does the RFSH/FLT pin behave during normal operation versus fault conditions?

When FLTEN = 0, RFSH/FLT outputs a configurable rectangular refresh signal synchronized to fPWM. When FLTEN = 1, it acts as an active-low open-drain fault flag: pulled low on LED open, LED short, UVLO, or OTP events. The corresponding fault register bits (e.g., CH1O, CH1S, FT_OTP) must be read to identify the root cause.

Can the MPQ3326BGRE-AEC1-P drive LEDs in series configurations?

No-the MPQ3326BGRE-AEC1-P is a constant-current sink driver with 16 individual cathode-connected outputs; it requires LEDs to be arranged in parallel strings (common-anode topology). Each channel supports up to 200–480mV headroom depending on current, limiting total forward voltage per string to

What is the purpose of the 40μs phase shift between LED channels?

The 40μs phase shift staggers PWM rising edges across all 16 channels to reduce peak input current demand and lower conducted EMI. This technique cuts RMS input ripple current by over 70% compared to simultaneous switching, easing input capacitor sizing and meeting CISPR 25 Class 5 requirements in automotive designs.

How is LED current calibrated per channel, and what tolerance applies?

LED current is set globally via the ISET resistor (e.g., 15kΩ yields 80mA typical); per-channel analog dimming then scales it using 6-bit ICHx register (0–63). At 25°C, full-scale current tolerance is ±3%; over −40°C to +125°C, it widens to ±5%. No per-channel trimming resistors are needed.

Does the MPQ3326BGRE-AEC1-P support both latch-off and hiccup modes for fault recovery?

Yes-via the LATCH bit in DEV_CON register (address 0x01). When LATCH = 1, faults cause permanent shutdown until power cycle or EN toggle. When LATCH = 0, the device enters hiccup mode: attempting conduction for 32μs every 1ms until fault clears, then auto-resuming normal operation without host intervention.

What PCB layout considerations are critical for thermal performance?

A minimum 120mm² exposed thermal pad (connected to solid GND plane) is required beneath the QFN-24 package. Use ≥6 thermal vias (0.3mm diameter, 0.6mm pitch) from pad to inner GND layers. Keep ISET and RADDR traces short and away from noisy switching nodes to prevent current-setting errors.