Monolithic Power Systems Inc. MPQ3367GR-Z

Overview

MPQ3367GR-Z from Monolithic Power Systems is a 6-channel, peak-current-mode boost WLED driver with integrated 100mΩ/50V MOSFET, I²C interface, and programmable switching frequency up to 2.2MHz. It delivers up to 150mA per channel with ±2.5% current matching, supports 15000:1 PWM dimming ratio at ≤200Hz, and targets LCD backlighting in automotive displays and tablets requiring high-efficiency, low-noise LED current regulation.

For engineers reviewing the MPQ3367GR-Z datasheet, MPQ3367GR-Z pinout, MPQ3367GR-Z application, or MPQ3367GR-Z equivalent, this page provides verified technical context, real-world dimming mode behavior, package-specific thermal resistance (42°C/W for QFN-24), fault flag signaling, and phase-shifted PWM timing for EMI reduction - all confirmed from MPS Rev. 1.2 documentation.

Technical Context

The MPQ3367GR-Z implements peak-current-mode control with cycle-by-cycle current limiting and a stabilizing ramp to suppress subharmonic oscillation above 50% duty. Its internal 5V LDO (VCC) powers gate drive and logic, enabling operation down to 3.5V input while maintaining stable regulation across -40°C to +125°C junction temperature.

Dimming is implemented via three hardware-selectable modes: direct PWM (fixed amplitude, variable duty), analog (DAC-based amplitude scaling), and mix dimming (25% or 12.5% transfer point). Phase shift-60° for 6 channels, 90° for 4-is synchronized to PWM edges to reduce inrush current and eliminate audible noise during dimming transitions.

Key Specifications

Pinout & Package

The MPQ3367GR-Z is packaged in a thermally enhanced QFN-24 (4mm × 4mm) with exposed pad tied to AGND, offering 42°C/W θ_JA on a 4-layer PCB. Pin functions are validated per MPS Rev. 1.2 datasheet and match the GR-AEC1 variant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 6-channel boost WLED driver applications.

Compared with RTQ2132B-QT and ISL97693IRTZ-T7A, the MPQ3367GR-Z uniquely integrates I²C configurability, phase-shifted PWM, and 15000:1 dimming in a single AEC-Q100-qualified QFN package - reducing component count, improving EMI performance, and enabling deeper dimming without external DACs or controllers.

Availability

MPQ3367GR-Z is available at Aetrix Electronics and suitable for automotive instrument clusters, tablet LCD backlights, infotainment displays, and industrial HMI panels requiring stable component supply, AEC-Q100 qualification, and high-ratio dimming capability.

Supply support for MPQ3367GR-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 design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPQ3367 belongs to MPS's automotive-qualified LED driver product line, engineered specifically for high-reliability LCD backlighting in vehicles and portable displays where precision current matching, low EMI, and deep dimming are critical.

FAQ

What dimming modes does MPQ3367GR-Z support, and how are they selected?

The MPQ3367GR-Z supports analog, PWM, and mix dimming. Selection is made either by resistor biasing the MIX/AD pin (low = mix, mid = PWM, high = analog) or via I²C register writes (MODE1:0 bits). Mix dimming uses a 25% or 12.5% transfer point to combine analog linearity at high brightness with PWM resolution at low brightness.

How does the phase-shift function reduce EMI and audible noise?

Phase shift staggers the turn-on timing of LED channel current sources - 60° apart for six active channels - spreading the input current ripple over time. This lowers peak inrush current by >40%, reduces conducted EMI amplitude at fundamental PWM frequencies, and eliminates mechanical vibration in inductors that causes audible coil whine below 20kHz.

Can MPQ3367GR-Z drive fewer than six LED strings, and how is channel disable handled?

Yes. Unused LEDx pins (e.g., LED6 for five-string operation) must be tied to GND through ≤470pF capacitors to enable automatic detection and removal from the feedback loop. Alternatively, the CH2:0 register bits can disable channels 2–6 individually, allowing flexible configuration from 1 to 6 active strings without hardware changes.

What protections are built into MPQ3367GR-Z, and how are faults signaled?

Protections include over-voltage (OVP, programmable), over-temperature (OTP, 170°C), LED open/short, inductor short, and cycle-by-cycle current limit. All faults assert the open-drain FF pin low and latch until EN is cycled or I²C reset command issued. OVP threshold is set via resistor divider on OVP pin; short-LED threshold is set via STH pin current source.

Is MPQ3367GR-Z compatible with 3.3V microcontrollers for I²C communication?

Yes. The SCL/PSE and SDA/PSE pins accept 0.4V low and 1.2V high logic thresholds, fully compatible with 3.3V I²C buses. Pull-up resistors should be connected to 3.3V (not VCC) when interfacing with 3.3V MCUs; internal 5V VCC powers only internal logic and gate drivers, not the I²C interface.

What is the minimum recommended ISET resistor value, and how does it affect current accuracy?

The ISET pin is a 1.2V reference with ±1% tolerance. For 150mA full-scale per channel, use R_ISET = 1.2V / 0.15A = 8kΩ (±0.5% metal film). Current accuracy degrades slightly at extremes: ±2.5% matching holds at 20–100mA, but drops to ±5% below 1mA due to DAC quantization in analog dimming mode.

Does MPQ3367GR-Z require external compensation, and what topology is supported?

Yes. COMP (Pin 7) requires an external RC network for loop stability. MPS recommends a Type II compensator: 10nF capacitor from COMP to AGND and 200kΩ resistor from COMP to VCC. The device supports standard boost topology with external inductor, diode, and output capacitor; no SEPIC or flyback configurations are supported.