Vin ---- C1 ----+----+--------------------+----> VOUT | | | | IC1 D1 | (JYMC‑220BI) | | |--- SW (pin 3) ----+---|<---+ | | | | | L1 (integrated) | | | | | | +----+--- GND ---------+----------+ | | C3 C2 | | GND GND In a real PCB you will see a thermal pad on the bottom of the IC that should be soldered to a copper area (often connected to ground) to aid heat dissipation. 4. Pin‑out & Electrical Characteristics | Pin | Name | Description | Typical Voltage | |-----|------|-------------|-----------------| | 1 | VIN | Input voltage (4.5 – 38 V) | – | | 2 | GND | Ground (common) | 0 V | | 3 | SW | Switching node (connects to the internal MOSFET) | Pulses between VIN and GND | | 4 | FB | Feedback (fixed internally for 5 V/12 V; external for adjustable) | ≈ 0.6 V (reference) | | 5 | EN | Enable pin (active‑high). Pull high to turn on; pull low to shut down. | 0 V or 3.3 V | | 6 | SS | Soft‑start control (optional). Usually left unconnected; pulling low reduces inrush current. | – | | 7 | TEMP | Internal temperature sensor (not usually accessed). | – |

| Feature | Benefit | |--------|----------| | 4.5 V – 38 V | Works with a wide variety of battery packs and wall‑adapter voltages. | | Fixed output: 5 V (1 A) or 12 V (0.5 A) depending on the variant | No external feedback network needed for the most common voltages. | | Integrated MOSFET + inductor | Minimal external parts → tiny PCB footprint (≈ 15 mm × 10 mm). | | Built‑in protection: over‑current, over‑temperature, under‑voltage lockout (UVLO) | Safer for both the module and the load. | | Low cost & high availability | Ideal for budget‑sensitive projects. |

(If you are looking for the official datasheet, you can download it from the manufacturer’s website or reputable component‑library sites – the link is provided at the end of this article.) 1. Why the JYMC‑220BI Matters The JYMC‑220BI is a compact, integrated step‑down (buck) switching regulator that has become a staple in low‑cost power‑supply designs for hobbyists, DIY‑electronics, and even some commercial products. Its appeal comes from:

Jymc220bi Schematic Full ◉

Vin ---- C1 ----+----+--------------------+----> VOUT | | | | IC1 D1 | (JYMC‑220BI) | | |--- SW (pin 3) ----+---|<---+ | | | | | L1 (integrated) | | | | | | +----+--- GND ---------+----------+ | | C3 C2 | | GND GND In a real PCB you will see a thermal pad on the bottom of the IC that should be soldered to a copper area (often connected to ground) to aid heat dissipation. 4. Pin‑out & Electrical Characteristics | Pin | Name | Description | Typical Voltage | |-----|------|-------------|-----------------| | 1 | VIN | Input voltage (4.5 – 38 V) | – | | 2 | GND | Ground (common) | 0 V | | 3 | SW | Switching node (connects to the internal MOSFET) | Pulses between VIN and GND | | 4 | FB | Feedback (fixed internally for 5 V/12 V; external for adjustable) | ≈ 0.6 V (reference) | | 5 | EN | Enable pin (active‑high). Pull high to turn on; pull low to shut down. | 0 V or 3.3 V | | 6 | SS | Soft‑start control (optional). Usually left unconnected; pulling low reduces inrush current. | – | | 7 | TEMP | Internal temperature sensor (not usually accessed). | – |

| Feature | Benefit | |--------|----------| | 4.5 V – 38 V | Works with a wide variety of battery packs and wall‑adapter voltages. | | Fixed output: 5 V (1 A) or 12 V (0.5 A) depending on the variant | No external feedback network needed for the most common voltages. | | Integrated MOSFET + inductor | Minimal external parts → tiny PCB footprint (≈ 15 mm × 10 mm). | | Built‑in protection: over‑current, over‑temperature, under‑voltage lockout (UVLO) | Safer for both the module and the load. | | Low cost & high availability | Ideal for budget‑sensitive projects. | jymc220bi schematic full

(If you are looking for the official datasheet, you can download it from the manufacturer’s website or reputable component‑library sites – the link is provided at the end of this article.) 1. Why the JYMC‑220BI Matters The JYMC‑220BI is a compact, integrated step‑down (buck) switching regulator that has become a staple in low‑cost power‑supply designs for hobbyists, DIY‑electronics, and even some commercial products. Its appeal comes from: Pull high to turn on; pull low to shut down