Low-side BCM Mode WLED Buck Controller
The MP4700 is a high-efficiency step-down converter designed to drive high-brightness light emitting diodes.
The MP4700 drives an external MOSFET in boundary conduction mode, which features no reverse recovery loss in the freewheeling diode and soft turn-on with zero-current and valley voltage for the power MOSFET that improves efficiency and minimizes the inductor value and size. The boundary conduction control mode regulates the LED current by sensing the MOSFET peak current through an external resistor. Its low 300mV feedback voltage reduces power loss and improves efficiency.
The MP4700 implements PWM dimming to the LED current.
Protection features include output short protection, under-voltage lockout for the IC input voltage and bus input voltage, a limited maximum switching frequency, and thermal shut down
- 8V-to-18V Input Voltage
- Constant-Current LED Driver
- Power MOSFET Zero-Current Turn-On
- No Freewheeling Diode Reverse Recovery Issues
- High Efficiency and Reliability in Boundary Conduction Mode
- Low 1mA Operation Current
- PWM Dimming Control
- Hiccup Short Circuit Protection
- UVLO for Bus Input Voltage
- Input UVLO, Thermal Shutdown
- Maximum Frequency Limited to 160kHz
- Available in SOIC8 Package
- Vin (min) (V)8
- Vin (max) (V)18
- fsw (min) (kHz)80
- fsw (max) (kHz)500
- Vfb (V)0.3
- Power MOSFETExternal
- Dimming (Output)P-Dim
- Iq (mA)0.6
- Typical LCD Screen SizesMedium (10"-29"), Large (30"-45"), Large+ (>45")
White LED Driver For TV Backlighting Applications
The EV4700-S-00A is the Evaluation Board designed to demonstrate the capabilities of MP4700 for TV backlighting applications. The MP4700 is a high efficiency step-down converter controller designed for driving the high brightness LEDs.
With a 250-300V input VIN and an 8-18V power supply for MP4700, the EV4700-S-00A can drive a LED string up to 200V, and the LED current is regulated to 250mA. The EVB realizes input UVLO by INUV pin, the PWM dimming can be implemented by applying a PWM dimming signal on PWM pin. The short LED load protection and Over-Voltage protection are included.
$25.00 + tax