LJTick-LVDigitalIO (LJT-LVDIO) 는 디지탈 3.3V 로직을 2.5V 혹은 1.8V 로 다운 변환 시키는 양방향 로직 shifting 보드 입니다.

There is also a VOUT terminal which can source power at the selected voltage. Useful for users who have external boards that run on lower logic thresholds, or simply want a 3.3V, 2.5V, or 1.8V supply.

• Supports bi-directional communication
• Up to 800kHz
• 3.3V, 2.5V, or 1.8V
• VOUT terminal can source up to 200mA

Note: Advanced users may convert the 1.8V option to 5V by installing a jumper on R5, and removing or destroying the voltage regulator marked U3. Instructions for doing this can be found on the modifying the LJTick-LVDigitalIO page.

Common Applications

• Communicating with SPI, I2C, UART, 1-Wire, and other Digital IO sensors that require a supply voltage that is the same voltage as the logic level.

Figure 1: LJTick-LVDigitalIO

Figure 2: LJTick-LVDigitalIO with U3-LV

Screw Terminal Descriptions

Vout: This voltage can be selected to be either 3.3V, 2.5V, or 1.8V with the slide switch.

GND: Same as LabJack ground (GND).

DIOA/DIOB: These logic input and output lines can be configured to communicate with 3.3V, 2.5V, or 1.8V circuitry.

 

LJTick-LVDigitalIO Hardware Block Diagram

Figure 3: LJTick-LVDigitalIO Hardware Block Diagram

 

LJTick-LVDigitalIO Schematic

Figure 4: LJTick-LVDigitalIO Schematic

 

Specifications:

Parameter	Conditions	Min	Typical	Max	Units
Supply Voltage		3.6		5.25	V
Supply Current	No Load		0.2		mA
Operating Temperature		-40		80	°C
Output Drive Current			100		mA
1.8V Logic Voltage
Vout Output Voltage			1.8		V
Vout Current			300		mA
Rise time			180		ns
Fall time			580		ns
Max Recommended Frequency	No load, 50% duty cycle		1		MHz
Logic High			1.78		V
2.5V Logic Voltage
Vout Output Voltage			2.5		V
Vout Current			300		mA
Rise time			560		na
Fall time			640		na
Max Recommended Frequency	No load, 50% duty cycle		1		MHz
Logic High			2.46		V
3.3V Logic Voltage
Vout Output Voltage			3.3		V
Vout Current			300		mA
Rise time			2		ns
Fall time			800		ns
Max Recommended Frequency (1)	No load, 50% duty cycle		1		MHz
Logic High			3.26		V
Logic High (Vmax) at max frequency	1MHz, no load, 50% duty cycle		3.1		V

(1) Frequencies higher than 350kHz will not produce the full logic high voltage.

For more specifications about the MOSFETs and voltage regulators used in the LJTick-LVDigitalIO look at the following datasheets:

• ON Semiconductor (Logic Level Shifters) NTR4003N datasheet.
• Diodes Incorporated (3.3V Regulator) AP2127K-3.3TRG1 datasheet
• Richtek (2.5V Regulator) RT9193 datasheet
• Diodes Incorporated (1.8V Regulator) AP2127K-1.8TRG1 datasheet

File Attachment: 

ON-Semiconductor-NTR4003N-Datasheet.PDF

Diodes-Incorporated-AP2127-Datasheet.pdf

Richtek-RT9193-Datasheet.pdf