Firstchip Yc2019 — Exclusive

A typical discrete solution—TP4056 charger + MT3608 booster + power path MOSFETs + load switches—requires at least 15-20 components. The Yc2019 reduces this to just 5-7 external parts. This shrinks PCB size and lowers assembly costs.

The Firstchip Yc2019 is a highly integrated, low-quiescent-current PMIC designed primarily for single-cell lithium-ion (Li-ion) and lithium-polymer (Li-Po) battery applications. Manufactured by Firstchip Microelectronics, a Shenzhen-based semiconductor company known for pragmatic, high-value analog ICs, the Yc2019 combines three critical functions into one tiny package:

The hallmark of this chip is its ability to operate as a "power bank on a chip." It can simultaneously charge the internal battery while powering an external load (like a USB fan, LED light, or Bluetooth speaker), making it ideal for portable devices that double as emergency power sources. Firstchip Yc2019

Because of its wide input range and 2A capability, the Yc2019 appears in dozens of everyday electronics, including:

The Yc2019 operates on a standard pulse-width modulation (PWM) architecture with a constant frequency. Here’s a simplified breakdown: The hallmark of this chip is its ability

The formula for setting the output voltage is simple: [ V_OUT = 0.8V \times (1 + R1 / R2) ] Where R2 is connected between FB and GND, and R1 is connected between VOUT and FB.

Example debug steps for connectivity issues: The formula for setting the output voltage is

Sample pseudocode:

wifi_init();
if (!wifi_connected) start_softap_for_provision();
sensor_init();
while (1) 
  temp = read_sensor();
  if (should_send(temp)) 
    connect_server();
    http_post("/api/temp", json(temp));
    disconnect();
sleep_minutes(1);