Zd-95-g-f: Schematic

ZD-95-G-F schematic — concise digest

7. Cross-referencing with Datasheets

• For ICs or specific components, refer to their datasheets to understand their function and pinout.

Typical Application Schematic (LED Driver Example)

If you were to draw the ZD-95-G-F schematic for a 7W LED bulb, it would look like this:

AC Input (90-265V) → Bridge Rectifier → Bulk Capacitor (400V)
                              │
                              ├─── Resistor (Startup) → Pin 5 (VCC)
                              │
                              ├─── Inductor/LED+ ──┐
                              │                   │
                           Pin 6 (DRAIN) ←──┘     │
                              │                   │
                           Pin 4 (CS) ──Resistor─→ GND
                              │
                           Pin 1 (FB) ← Resistor Divider ← LED+
                           Pin 2 (GND)
                           Pin 3 (NC or Capacitor to GND)

Key external components:

• R_start (1-2 MΩ) – Provides initial VCC from the high-voltage bus.
• L1 (1-3 mH inductor) – Stores energy; the freewheeling diode (usually an RS1M or ES1J) goes from DRAIN to GND.
• R_cs (1-5 Ω, 1%) – Sets the peak current, thus LED brightness.
• R_fb1 / R_fb2 (e.g., 100kΩ and 20kΩ) – Sets output voltage (V_out = V_ref * (1 + R_fb1/R_fb2)).

4. Voltage Rails and Ground

• Find the power supply lines (e.g., +Vcc, -Vcc, GND).
• Understand how power is distributed and where grounds are connected.

Step 5: Confirm CS (Pin 4)

Pin 4 will go to a low-ohm sense resistor (typically 1-5 Ω, often labeled R_sense) whose other terminal goes to GND. This pin should show less than 10 Ω to GND through that resistor. zd-95-g-f schematic