2 in 1 DC 5V–3,3V Buck Setp-dowm AMS1117-3,3V LDO feszültségszabályozó modul és alapellenállás TTL logikai szintátalakító kártya
2 in 1 DC 5V to 3.3V Buck Setp-dowm AMS1117-3.3V LDO Voltage Regulator Module & Base Resistor TTL Logic Level Converter Board
Product Name : 2 in 1 DC 5V to 3.3V Buck Setp-dowm AMS1117-3.3V LDO Voltage Regulator Module & Base Resistor TTL Logic Level Converter Board 
 
 
 
 
Packing list:
 
1 pcs 2 in 1 5V to 3.3V DC-DC Buck Module & Base Resistor TTL Logic Level Converter Board ;
 
 
 
Description: 
 
1 On board DC 4.5V-9V to 3.3V DC-DC Step-Down Power Supply Buck LDO Module,IC AMS1117-3.3;
2 On board 8 channels 5V to 3.3V(also 3.3V to 5V) Logic level converter,base Limiting resistor;
3  2.54MM Pin,UNO MEGA2560 Breadboard friendly;
  
4 PCB size:25* 15mm 
  
   
Application:
  
Arduiuo UNO MEGA2560 DUE Pro mini Nano
NRF24L01
NRF24LE1
CC2500
ZIGBEE/CC2530
FPGA/CPLD ARM AVR PIC C8051 C51 MSP430
MCU Development Board
 
TTL Level conversion principle:
Between 5V and 3.3V level plus 470 ohm current limiting resistor, to avoid being burned of 3.3V port.
So, when the LOW side no-load, HIGH side plus 5V level,LOW side test is still at 5V level,vice versa.
This is a normal phenomenon, not the level conversion function does not work. 
Schematics:
 

 
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