YX862A Solar NiCd LED Driver

Low-cost Chinese IC (YX862A) for solar-powered garden lights: Charges NiCd battery from solar cell, boosts voltage for constant/blinking LEDs. Perfect for DIY outdoor LEDs, emergency lights, or embedded prototypes—matches your PCB experimentation style.

Features

• Solar Charging: Direct solar input (SOL) trickle-charges NiCd BAT (1.2V typical).
• LED Driving: Boost converter (LX inductor) powers LEDs at VDD; supports constant light (VCC) or blinking (MOD to GND).
• Status Flags: PWROK/PWRFLAG open-drain for low-battery alert; PGND separated for noise.
• Mode Control: MOD pin selects LED modes (GND for blink, float/open for constant).
• Efficiency: ~80-85% boost; TSET1/2 thermistors for temp protection.
• Compact: Single-chip SMD solution (SOP-8), fits 1-layer PCB.

How It Works

1. Daytime: Solar cell voltage on SOL charges NiCd BAT via internal linear regulator.
2. Nighttime: BAT powers boost (LX coil, diodes) to VDD (~3V for LEDs).
3. LED Modes:
   • VCC to LEDs: Constant light.
   • MOD to GND: Blinking/flashing (internal oscillator).
4. Protection: PWROK flags low BAT; PWFLAG for over-discharge.
5. Tested for NiCd (not Li-ion watch polarity/reverse charging).

Bill of Materials (BOM)

Ref	Component	Value/Type	Footprint	Example	Qty	Notes
C1	Cap	10uF	0603	MLCC	1	VDD filter
U1	IC	YX862A	SOP-8	AliExpress	1	Solar LED driver
L1	Inductor	10-47uH	Axial/SMD	22uH/1A	1	Boost LX (>1MHz)
R1-R2	Res	4.7k/47k	0603	1%	4	Divider/TSET
LED1/2	LED	White 0603	0603	High-bright	2	String/array
J1-J3	Conn	Solar/BAT/LED	Header	2-pin	3	Prototyping

Sourcing: AliExpress/LCSC (~$0.20/IC), JLCPCB assembly.

Usage & Testing

• Solar Input: 2-6V panel to SOL/GND.
• Battery: NiCd AA/AAA to BAT/PGND (observe polarity!).
• LEDs: VCC to LED+ chain, LED- to GND.
• Modes: Short MOD-GND for blink; leave open for constant.