SNOSC82B August   2012  – June 2015 DS1776QML

PRODUCTION DATA.  

  1. 1Features
  2. 2Description
  3. 3Revision History
  4. 4Pin Configuration and Functions
  5. 5Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommend Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Quality Conformance Inspection
    6. 5.6  Pi Bus Transceiver DS1776 DC Parameters
    7. 5.7  Pi Bus Transceiver DS1776 AC Parameters: B To A Path
    8. 5.8  Pi Bus Transceiver DS1776 AC Parameters: A To B Path
    9. 5.9  Pi Bus Transceiver DS1776 AC Parameters: Setup / Hold / Pulse Width Specifications
    10. 5.10 Test Circuit And Waveforms
      1. 5.10.1 Test Circuit For TRI-STATE Outputs On A Side
      2. 5.10.2 Test Circuit For TRI-STATE Outputs On B Side
      3. 5.10.3 Input Pulse Definition
  6. 6Detailed Description
    1. 6.1 Controller Power Sequencing Operation
  7. 7Device and Documentation Support
    1. 7.1 Community Resources
    2. 7.2 Trademarks
    3. 7.3 Electrostatic Discharge Caution
    4. 7.4 Glossary
  8. 8Mechanical, Packaging, and Orderable Information

Package Options

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

6 Detailed Description

DS1776QML 20164204.png
VCC = Pin 1

VX = Pin 14

Gnd = Pins 4, 8, 11, 18, 22, 25
Figure 6. Functional Logic Diagram

Table 3. Function Table(1)

Inputs Latch Outputs Mode
An Bn(2) LE OEA OEB 0 OEB 1 State An Bn
H X L L L L H Z H A TRI-STATE, Data from A to B
L X L L L L L Z L
X X H L L L Qn Z Qn A TRI-STATE, Latched Data to B
— — L H L L See(4) See(2) See(2) Feedback: A to B, B to A
— H H H L L H(3) H off(3) Preconditioned Latch Enabling
— L H H L L H(3) L off(3) Data Transfer from B to A
— — H H L L Qn Qn Qn Latch State to A and B
H X L L H X H Z off
L X L L H X L Z off B off and A TRI-STATE
X X H L H X Qn Z off
— H L H H X H H off
— L L H H X L L off
— H H H H X Qn H off B off, Data from B to A
— L H H H X Qn L off
H X L L X H H Z off
L X L L X H L Z off B off and A TRI-STATE
X X H L X H Qn Z off
— H L H X H H H off
— L L H X H L L off B off, Data from B to A
— H H H X H Qn H off
— L H H X H Qn L off
(1) H = High Voltage Level
L = Low Voltage Level
X = Don't Care
— = Input not externally driven
Z = High Impedance (off) state
Qn = High or Low voltage level one setup time prior to the Low-to-High LE transition
(2) Condition will cause a feedback loop path; A to B and B to A.
(3) The latch must be preconditioned such that B inputs may assume a High or Low level while OEB 0 and OEB 1, are Low and LE is high.
(4) Precaution should be taken to ensure that the B inputs do not float. If they do, they are equal to a Low state.

6.1 Controller Power Sequencing Operation

The DS1776 has a design feature which controls the output transitions during power up (or down). There are two possible conditions that occur.

  1. When LE = Low and OEBn = Low, the B outputs are disabled until the LE circuit can take control. This feature ensures that the B outputs will follow the A inputs and allow only one transition during power up (or down).
  2. If LE = High or OEBn = High, then the B outputs still remain disabled during power up (or down).