Difference between revisions of "OPTOUSB"
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== Separate Power Domains == | == Separate Power Domains == | ||
| − | The OPTOUSB card has two distinct power domains. | + | * The OPTOUSB card has two distinct power domains. |
| − | One of the domains is the USB side where the power comes from the USB connector/cable. | + | ** One of the domains is the USB side where the power comes from the USB connector/cable. |
| − | The other power domain is on the TTL side where the power comes from the FTDI connector. | + | ** The other power domain is on the TTL side where the power comes from the FTDI connector. |
| − | This is unlike "normal" FTDI interfaces where the USB connection can power the FTDI side. | + | * This is unlike "normal" FTDI interfaces where the USB connection can power the FTDI side. |
| − | This is the purpose of the optical isolation - to isolate the ground of the USB side from the target (FTDI) side. | + | ** This is the purpose of the optical isolation - to isolate the ground of the USB side from the target (FTDI) side. |
| − | Connectors | + | |
| − | J1 - Mini USB Connector | + | == Connectors == |
| − | Standard USB Mini connector | + | |
| − | J2 - Transmit/Receive LED connections | + | === J1 - Mini USB Connector === |
| − | PUP0 - LED Pullup to USB Power | + | |
| − | TXLED - Transmit LED | + | * Standard USB Mini connector |
| − | PUP1 - LED Pullup to USB Power | + | |
| + | === J2 - Transmit/Receive LED connections === | ||
| + | |||
| + | # PUP0 - LED Pullup to USB Power | ||
| + | # TXLED - Transmit LED | ||
| + | # PUP1 - LED Pullup to USB Power | ||
RXLED - Receive LED | RXLED - Receive LED | ||
J3 - FTDI Connector | J3 - FTDI Connector | ||
Revision as of 12:41, 10 January 2020
Contents
Features
- USB to TTL level Serial (FTDI) Interface
- Genuine FTDI FT230XS part
- Standard FTDI drivers
- Buffered lines on the TTL level side
- Schmidt Trigger
- Voltage level hysteresis
- Improved slew rate
- Schmidt Trigger
- OptoIsolated Connections
- Transmit, Receive, RTS, CTS
- Configured for High Speed Serial
- The Host USB connection is independent of the state of the FTDI side of the interface
- Host side can communicate with the USB host whether or not the target is even powered up
- Target power on/off doesn't cause a USB disconnect - handy for debug
- Fast operation
- 3.3V or 5V FTDI voltage (order option)
- Transmit/Receive LED Connectors
- On-board LED resistors
- 49x49mm card
- (4) #4 Mounting Holes
Block Diagram
Separate Power Domains
- The OPTOUSB card has two distinct power domains.
- One of the domains is the USB side where the power comes from the USB connector/cable.
- The other power domain is on the TTL side where the power comes from the FTDI connector.
- This is unlike "normal" FTDI interfaces where the USB connection can power the FTDI side.
- This is the purpose of the optical isolation - to isolate the ground of the USB side from the target (FTDI) side.
Connectors
J1 - Mini USB Connector
- Standard USB Mini connector
J2 - Transmit/Receive LED connections
- PUP0 - LED Pullup to USB Power
- TXLED - Transmit LED
- PUP1 - LED Pullup to USB Power
RXLED - Receive LED J3 - FTDI Connector Signals are references to external system GND RTS (In to card) VCC (3.3V or 5V) - Power must be supplied to this pin Receive (Out from card) Transmit (In to card) CTS (Out from card) Drivers FTDI Drivers Layout OPTOUSB-CAD-X1.PNG
Transfer Rate Characterization LTSpice Simulation results 8.6uS per bit = 115,200 baud OPTO-USB LTSpice Simulation.png
Card Test UUT 5V Power Supply Loopback/FTDI Cable Pin 1 = Ground (5V Supply) Pin 3 = Vcc (5V Supply) Pin 2 - Pin 6 RTS/CTS Loopback Pin 4 - Pin 5 Tx/Rx Loopback Run puTTY Run Device Manager to determine COM port Set baud rate to TBD (115,200?) Loopback test Rework - Rev X1 PWBs OPTOUSB_Rev_X1_Rework
