Passive redundant digital data receiver with dual comparator edge detection
First Claim
Patent Images
1. A digital signal receiver, comprising:
- a passive coupling structure having a signal input, a low frequency component output, and a high frequency component output;
a level based receiver having a first input connected to said low frequency component output and a first output;
a first comparator having a first comparator output and also having a first first comparator input connected said high frequency component output and a second first comparator input connected to a first reference voltage;
a second comparator having a second comparator output and also having a first second comparator input connected to said high frequency component output and a second second comparator input connected to a second reference voltage and wherein said high frequency component output is biased to a DC voltage level that is between said first and said second reference voltage; and
,a state machine, receiving said first and second comparator outputs and said first output, that changes a receiver output when said first output and at least one of said first and second comparator outputs transition in at least one direction.
2 Assignments
0 Petitions
Accused Products
Abstract
A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.
-
Citations
19 Claims
-
1. A digital signal receiver, comprising:
-
a passive coupling structure having a signal input, a low frequency component output, and a high frequency component output; a level based receiver having a first input connected to said low frequency component output and a first output; a first comparator having a first comparator output and also having a first first comparator input connected said high frequency component output and a second first comparator input connected to a first reference voltage; a second comparator having a second comparator output and also having a first second comparator input connected to said high frequency component output and a second second comparator input connected to a second reference voltage and wherein said high frequency component output is biased to a DC voltage level that is between said first and said second reference voltage; and
,a state machine, receiving said first and second comparator outputs and said first output, that changes a receiver output when said first output and at least one of said first and second comparator outputs transition in at least one direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A redundant digital receiver, comprising:
-
a level based receiver coupled to the low frequency output of a passive coupling structure comprised of two parallel circuit lines; a dual comparator receiver having high and low trip points that is coupled to the high frequency output of said passive coupling structure; at least one resistor that sets a DC bias on said high frequency output wherein said DC bias is between said high and low trip points of said dual comparator receiver; and
,a state machine block that receives a level based output from said level based receiver and two edge based outputs from said dual comparator receiver and combines those outputs to change the state of a receiver output only when both said level based and said edge based outputs indicate that a state change on an input signal to said passive coupling structure has occurred. - View Dependent Claims (14, 15)
-
-
16. A method of receiving digital signals, comprising:
-
splitting an input signal into a high frequency component and a low frequency component; detecting a state of said low frequency component using a level based receiver to produce a level based output; detecting an occurrence of a first edge in a first direction on said high frequency detecting an occurrence of a second edge in a second direction on said high frequency component using a second comparator to produce a second edge based output component using a first comparator to produce a first edge based output; combining said level based and said edge based output to set the state of a receiver output when said level based and said first edge or second edge based output indicate that a state change on said input signal has occurred. - View Dependent Claims (17, 18, 19)
-
Specification