一、GENERAL DESCRIPTION 
CXW8503 is a wide input voltage, high 
efficiency CC  and CV  step-down DC/DC 
converter that operates in either CV (Constant 
Output Voltage) mode or CC (Constant Output 
Current) mode.
CXW8503 provides low-ripple power, high 
efficiency, and excellent transient characteristics. 
The PWM control circuit is able to the duty ratio 
linearly forms 0 up to 90%. An over current 
protection and short circuit protection functions 
are built outside that it can set by a resistance. An 
external compensation is easily to system stable; 
the low ESR output capacitor can be used.
With the addition of an internal N-channel 
Power MOS, a coil, capacitors, and a diode 
connected externally, these ICs can function as 
step-down switching regulators. They serve as 
ideal power supply units for portable devices 
when coupled with the SOP-8L and SOP-8L-EP 
packages, providing such outstanding features as 
low current consumption. Since this converter can 
accommodate an input voltage up to 40V, it is 

also suitable for the operation via an AC adapter.

二、FEATURES  
- Perfect Solution for Car Charger
- Input Voltage：8V to 40V 
- High CC accuracy ±5%
- High CV accuracy ±2%
- Duty ratio：0% to 90% PWM control 
- Oscillation frequency：
100K Hz for CXW8503A 
200K Hz for CXW8503B
- Thermal Shutdown function. 
- Short Circuit Protect (SCP). 
- Built-in internal SW N-channel MOS. 
- Current mode non-synchronous PWM 
converter 
- Cycle to cycle Current Limiting
- External current limit setting. 
- Under Voltage Lockout. 
- Over Voltage Protection.