SLLSFI7 October   2020 SN65HVD64

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Coaxial Interface
      2. 8.3.2 Reference Input
      3. 8.3.3 RS-485 Direction Control
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Driver Amplitude Adjust
      2. 9.1.2 Direction Control
      3. 9.1.3 Direction Control Time Constant
      4. 9.1.4 Conversion Between dBm and Peak-to-Peak Voltage
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.4 Device Functional Modes

If DIRSET1 and DIRSET2 are in a logic high state, the device will be in standby mode. While in standby mode, the receiver functions normally, detecting carrier frequency activity on the RXIN pin and setting the RXOUT state. The transmitter circuits are not active in standby mode, thus the TXOUT pin is idle regardless of the logic state of TXIN. The supply current in standby mode is significantly reduced, allowing power savings when the node is not transmitting.

When not in standby mode, the default power-on state is idle. When in idle mode, RXOUT is high, and TXOUT is quiet. The device transitions to receive mode when a valid modulated signal is detected on the RXIN line or the device transitions to transmit mode when TXIN goes low. The device stays in either receive or transmit mode until DIR time-out (nominal 16 bit times) after the last activity on RXOUT or TXIN.

When in receive mode:

  • RXOUT responds to all valid modulated signals on RXIN, whether from the local transmitter, a remote transmitter, or long noise burst.
  • TXOUT responds to TXIN, generating 2.176-MHz signals on TXOUT when TXIN is low, and TXOUT is quiet when TXIN is high. (In normal operation, TXIN is expected to remain high when the device is in receive mode.)
  • The device stays in receive mode until 16 bit times after the last rising edge on RXOUT, caused by valid modulated signal on the RXIN line.

When in transmit mode:

  • RXOUT stays high, regardless of the input signal on RXIN.
  • TXOUT responds to TXIN, generating 2.176-MHz signals on TXOUT when TXIN is low, and TXOUT is quiet when TXIN is high.
  • The device stays in transmit mode until 16 bit times after TXIN goes high.

Table 8-1 shows the driver functions. Table 8-2 shows the receiver functions. Figure 8-1 shows the transitions between each state.

Table 8-1 Driver Function Table
TXIN(1)[DIRSET1, DIRSET2]TXOUTCOMMENT
H[L,L], [L,H] or [H,L]< 1 mVPP at 2.176 MHzDriver not active
LVOPP at 2.176 MHzDriver active
X[H,H]< 1 mVPP at 2.176 MHzStandby mode
(1) H = High, L = Low, X = Indeterminate
Table 8-2 Receiver and DIR Function Table
RXIN(1)RXOUTDIRCOMMENT (see Figure 8-1)
IDLE mode (not transmitting or receiving)
< VIT at 2.176 MHz for longer than DIR time-outHLNo outgoing or incoming signal
RECEIVE mode (not already transmitting)
< VIT at 2.176 MHz for less than tDIR time-outHHIncoming 1 bit, DIR stays HIGH for DIR time-out
> VIT at 2.176 MHz for longer than tnoise filterLHIncoming 0 bit, DIR output is HIGH
TRANSMIT mode (not already receiving)
XHLOutgoing message, DIR stays LOW for DIR time-out
(1) H = High, L = Low, X = Indeterminate
GUID-2B68450C-B4F6-414B-B5F8-ECDDD2C3A28D-low.gifFigure 8-1 State Transition Diagram