Datasheet - Sn51dp

The power button clicks. Suddenly, 12V of potential surges toward Pin 1 (VIN). The SN51DP doesn't flinch; its internal 3.3V regulator stabilizes, and its heart—a high-precision Digital Pulse Width Modulator (DPWM)

The internal oscillator switches the internal bipolar or MOSFET transistor at ~60kHz. When the switch turns on, current flows through L1 to the output. When off, D1 freewheels the inductor current. The FB pin compares the output voltage (divided by R1/R2) to the internal 1.23V reference, adjusting the duty cycle to maintain regulation. sn51dp datasheet

: Commonly available in MSOP-10 (Mini Small Outline Package) or SOP-10 formats, suitable for space-constrained PCB layouts. The power button clicks

: Operating near its maximum junction temperature (125°C) in sealed enclosures can significantly reduce its lifespan. LED driver IC replacement. When the switch turns on, current flows through

The SN51DP is housed in a (often labeled as SIP-5 or TO-220-5). Unlike standard TO-220 packages, the mounting tab is electrically isolated, simplifying heat sink attachment.

| Parameter | Value / Range | Remarks | |-----------|---------------|---------| | | DIP-6 (0.3" lead spacing) | Through-hole, also available in SMD (SN51DP-S) | | Input Diode Forward Current (IF) | 50 mA (max) | Typically driven at 5–20 mA | | Reverse Input Voltage | 6 V (max) | | | Output Blocking Voltage (VDRM) | 600 V (min) | Suitable for 110/230 VAC mains | | On-State Current (ITRMS) | 100 mA | Direct control only for tiny loads; usually drives a power triac | | Peak Surge Current (ITSM) | 1.2 A (non-repetitive) | | | Zero-Crossing Voltage | ±20 V (typical) | Activates within ~20V of AC zero crossing | | Isolation Voltage | 5000 Vrms (min) | Reinforced isolation | | Operating Temperature | -30°C to +100°C | |