Top - Lad402p Schematic

| Possible Part Number | Most Likely Device | Key Characteristics | | :--- | :--- | :--- | | | Audio Coupling Transformer | 600 Ohm Impedance, 90mA DC, 300Hz - 3.5kHz frequency range, 1.5kV isolation | | PTC402P | NPN Darlington Transistor | High-gain switching transistor in a TO-220 package | | LA402P | Line Source Speaker System | Professional audio, line array topology for high intelligibility |

Coil ENERGIZED (Operated state):

Understanding the LAD402P Schematic: A Technical Guide to Top-Layer Analysis lad402p schematic top

The loop area formed by the input capacitor, the high-side MOSFET, and the low-side diode/MOSFET is kept as short as possible to drastically reduce parasitic inductance and EMI ringing.

NO-1: Terminal 13 ----/ (open) ---- Terminal 14 NO-2: Terminal 23 ----/ (open) ---- Terminal 24 | Possible Part Number | Most Likely Device

[ 5 V = 1.2 V \times (1 + 3.3k/1k) ≈ 5.04 V ]

Verify that the wires are connected to the correct terminal number as per the design schematic. Each pole has two screws (line and load)

When working with the LAD402P schematic top, keep in mind the following tips and best practices:

[USB-C Charger Input] ──> [PD Controller (20V)] ──> [+VIN Primary Rail] │ ┌──────────────────────────────────────────────────────┴──────────────────────────────────────────────────────┐ ▼ ▼ ▼ [+3.1V_ALWAYS / +5V_ALWAYS] [+1.2V_DDR3L / LPDDR3] [+VCC_CORE CPU Rail] (Power Button & EC Active) (System Memory Active) (Post-S0 Execution) : Power arrives through the USB-C charging port.

Each pole has two screws (line and load). For NO-1: 13 (in) and 14 (out). Some older schematics label by pole only.