LM3401 Hysteretic PFET Controller for High Power LED Drive
TI LM3401MM Summary
The LM3401 is a switching controller designed to provide constant current to high power LEDs. The LM3401 drives an external P-MOSFET switch for step-down (Buck) regulators. The LM3401 delivers constant current within ±6% accuracy to a wide variety and number of series connected LEDs. Output current is adjusted with an external current sensing resistor to drive high power LEDs in excess of 1A.
For improved accuracy and efficiency, the LM3401 features dual-side hysteresis, very low reference voltage, and short propagation delay. A cycle by cycle current limit provides protection against over current and short circuit failures. Additional features include adjustable hysteresis and a CMOS compatible input pin for PWM dimming.
TI LM3401MM product features
■Hysteretic Control for Speed and Simplicity
■Input Operating Range of 4.5V-35V
■1.5MHz Maximum Switching Frequency
■Low 200mV Reference Voltage
■Programmable Current Limit
■High speed CMOS Compatible Enable/Dimming
■Adjustable Hysteresis
■Input UVLO
■No output Capacitor Required
■8-pin VSSOP Package
TI LM3401MM application
■LED Driver
■Battery Charger
TI LM3401MM Typical Application
TI LM3401MM CONNECTION DIAGRAM
TI LM3401MM PACKAGING INFORMATION
Orderable Device
| Package Type | Pins | Package Qty |
LM3401MM
| MSOP-8
| 8
| 1000 |
| LM3401MMX | 3500 |
TI LM3401MM PIN DESCRIPTIONS
| Pin # | Pin Name | Description |
| 1 | CS
| Current sense pin. Connect to the PFET drain |
| 2 | DIM
| Dimming input pin. When DIM is low, the HG drive is off. Can be connected to a logic level PWM signal
|
| 3 | SNS
| Current feedback pin – to LED cathode. Connect a resistor from this pin to ground to set the DC LED current
|
| 4 | HYS
| Hysteresis adjust pin. Connect a resistor from this pin to GND to set the hysteresis window |
| 5 | GND
| Ground pin |
| 6 | HG
| Gate drive output. Connect to the PFET gate
|
| 7 | VIN
| Power supply input |
| 8 | ILIM
| Current limit adjust pin. Connect a resistor from this pin to the PFET source to set the current limit threshold
|
