Texas Instruments Corporation

Julie Hwang

Mark William Morgan

Steven J Tinsley

Alan Stephen Bass

Woo Jin Kim

Hector Torres

A bidirectional repeater and data multiplexer for serial data has A-sideC port devices A-Acoupled to comparators-and pull-downs to ground-. Comparator outputs are coupled responsive to select lines S-Sof N:1 Selectto terminal Aof bidirectional controlto control pull-down to non-zero low voltage Vpat B-side device B. An inverting comparatorcoupled to terminal Bof bidirectional controlresponds to input threshold voltage Vt less than low voltage Vp, to prevent data lockup due to data flowback to devices A-A. Output data from comparatoris coupled responsive to select lines S-Sof 1:N Selectto control pull-downs-. This selectively repeats routing of device A-Adata to device B. Data from device B is selectively routed to pull-downs of devices A-A

Bidirectional data repeater switch

A bidirectional repeater and data multiplexer for serial data has A-side I2C port devices A-Acoupled to comparators-and pulldowns to ground-. Comparator outputs are coupled responsive to select lines S-Sof N:l Selectto terminal Aof bidirectional controlto control pulldown to non-zero low voltage Vpat B-side device B. An inverting comparatorcoupled to terminal Bof bidirectional controlresponds to input threshold voltage Vt less than low voltage Vp, to prevent data lockup due to data flowback to devices A-A. Output data from comparatoris coupled responsive to select lines S-Sof 1:N Selectto control pulldowns-. This selectively repeats routing of device A-Adata to device B. Data from device B is selectively routed to pulldowns of devices A-A

A high-speed front-multiplexed multi-channel LVDS-compatible repeater circuit that limits input leakage current levels in the event one or more input voltages of the circuit exceeds the supply voltage. The LVDS repeater includes a multiplexor having a plurality of differential inputs and at least one differential output. The multiplexor includes a plurality of transmission gates to allow any one of the differential inputs to be routed to any differential output. Each transmission gate includes a first PMOS transistor and an NMOS transistor. The multiplexor further includes first Schottky diodes coupled between Vcc and the back-gate nodes of the first PMOS transistors, and second PMOS transistors coupled as shunts between the gate nodes of the first PMOS transistors and the source nodes of the NMOS transistors. The first Schottky diodes block the back-gate diode-to-Vcc leakage current paths and the second PMOS transistors block the leakage current paths from the differential inputs to the first PMOS transistors when the input voltage exceeds Vcc.

Input current leakage correction for multi-channel LVDS front multiplexed repeaters

The present invention provides a method, system and apparatus for providing failsafe detection for a differential receiver. A bus activity signal () is activated when receiving a differential data signal of sufficient amplitude to transition through a predetermined threshold. A failsafe signal () indicates a low differential voltage condition. A countdown time period commences () upon activation of either signal, and a failsafe condition is determined () to exist if the failsafe signal is active () when the countdown time period expires ().

Active failsafe detection for differential receiver circuits

A driver ( ) which meets wide common mode voltage requirements is provided. Output passgates ( ) protect sensitive line driver circuitry ( ) from extreme bus voltages; enabling/disabling circuits ( ) detect fault conditions to ensure the line driver is disabled when needed, and pull-ups ( ) assist in line driver start up by preventing negative voltage conditions on the bus driven by the line driver.

Extended common mode differential driver

The present invention provides improved slew rate control over a varied operating temperature range. A switching device (P , N ) receives from a predrive circuit ( ) a control signal that limits a slew rate of the switching device's output and also varies proportionally to the operating temperature. In this manner, the effect of temperature on the slew rate can be reduced.

Temperature compensated slew rate control circuit

The output slew rate of a differential transmission line driver ( ) can be limited by suitably controlling signal slew rates ( ) at the control inputs (neg, pos) of the drive switches (M -M ) that control current flow through the load impedance (Rload) of the driver.

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Richardson, TX, United States of America

Julie Hwang