6-Channel, Max 100mA/Ch Boost WLED Driver with 15000:1 Dim Ratio and I2COctober 14, 2019 by Paul Shepard
The MPQ3369-AEC1 from Monolithic Power Systems is a step-up dc-dc converter with six channel current sources, designed to drive white LED arrays as backlighting in small-to-mid-size LCD panels. The MPQ3369-AEC1 uses peak current mode as its PWM control architecture to regulate the boost converter.
Six channel current sources are applied into the LED cathode to adjust the LED brightness. It regulates the current in each LED string to the value set via an external current-setting resistor, with 2.5% current regulation accuracy between strings.
The MPQ3369-AEC1 employs a low on-resistor MOSFET and a low headroom voltage, designed for higher efficiency. It has a standard I2C digital interface for ease of use. The switching frequency can be programmed by a resistor, I2C interface, or external clock.
The device provides analog, PWM, and mix dimming mode with a PWM input. The dimming mode can be selected with the I2C interface or the MIX/AD pin. It also has a phase shift function to eliminate noise during PWM dimming.
Robust protections are included to guarantee safe operation of the device. Protection modes include over-current protection (OCP), over-voltage protection (OVP), over-temperature protection (OTP), LED short, and open protection. There is also an option that decreases the LED current automatically at higher temperatures.
The MPQ3369-AEC1 is available in QFN-24 (4mmx4mm) and TSSOP28-EP packages.
Summary of Features
- 5V to 36V Input Voltage Range
- 6 Channels with Max 100mA per Channel
- Internal 100mΩ, 50V MOSFET
- Programmable Up to 2.2MHz fSW
- External Sync SW Function
- Multi-Dimming Operation Mode through PWM Input, Including:
- Direct PWM Dimming
- Analog Dimming
- Mix Dimming with 25%/12.5% Transfer Point
- 15000:1 Dim Ratio in PWM Dim at fPWM ≤ 200Hz
- 200:1 Dim Ratio at Analog Dim through PWM Dim Signal Input
- Excellent EMI Performance, Frequency Spread Spectrum
- I2C Interface
- Phase Shift Function for PWM Dimming
- 5% Current Matching
- Cycle-by-Cycle Current Limit
- Disconnect VOUT from VIN
- Optional LED Current Auto-Decrement at High Temperature
- LED Short/Open, OTP, OCP, Inductor Short Protection
- Programmable LED Short Threshold
- Programmable OVP Threshold
- Fault Indicator Signal Output
- Available in QFN-24 (4mm x 4mm) and TSSOP28-EP Packages
- AEC-Q100 Qualified