Mp3378e Protection Pin Upd Info
Technicians often check the voltage on this pin; if it exceeds the internal reference, the IC shuts down. In some ICs (like the related MP3398E), connecting a to ground can stabilize protection behaviors . Disabling Protection (For Diagnosis Only):
If the current through the inductor exceeds the threshold, the driver stops switching. 3. MP3378E Protection Troubleshooting Procedures
If one string is damaged, you can sometimes connect the faulty string's input to a functional channel (via a resistor), effectively tricking the IC into thinking all 4 strings are active. Summary of MP3378E Features 4-String WLED Controller: Max 350 mA/string. External MOSFET Drive: Drives boost converter. Input Range: Up to 24 V. Dimming: Supports both analog and PWM dimming. Package: Available in SOIC28 and TSSOP28EP.
Not a separate pin – UPD refers to the via register or external logic on MP3378E (depending on variant). In practice: mp3378e protection pin upd
: These source-sink pins monitor the cathode voltages of the LED strings. If a string shorts out, the voltage on that specific pin spikes. If it stays too high or drops too low (indicating an open string), the chip marks it as a fault.
: Monitors real-time operation for Over-Current Protection (OCP), Over-Voltage Protection (OVP), Under-Voltage Protection (UVP), Over-Temperature Protection (OTP), LED open/short circuit detection, and physical inductor/diode short-circuits.
The MP3378E's multiple protection mechanisms can sometimes trigger unexpectedly, especially in field repairs or derivative designs. Here are common issues: Technicians often check the voltage on this pin;
: Verify that the high-megohm resistors connected to the OVP pin haven't drifted in value. A drifted resistor artificially lowers the protection threshold, causing false triggers.
: If a string is open, its LEDx pin voltage drops to near zero while the output voltage hits the OVP threshold; the IC then disables that specific string.
The you are getting across the VLED or OVP pins? External MOSFET Drive: Drives boost converter
[ V_OUT(OVP) = 2.0V \times \left(1 + \fracR_TOPR_BOTTOM\right) ]
Protects the chip from overheating. The Role of the "UPD" or Fault Detection Circuitry
Because these changes affect system safety and user experience, check the latest datasheet and errata when using the MP3378E and confirm behavior through bench testing with the target load and transient conditions.
