US 6,646,479 B1 · Pulse discriminator

Abstract

A non-delayed input signal is provided to a first comparator input and, a delayed input signal is applied to a second comparator input. An offset voltage is applied between the delayed and non-delayed signals at the comparator inputs. When an input pulse appears on the input signal, the non-delayed input signal will rise immediately and maintain itself more positive than the delayed input, keeping the comparator output inactive. As long as the input signal is rising, the comparator output is maintained low, or inactive. When the non-delayed signal reaches its peak and turns downward, the delayed input signal is still rising and crosses over the first pulse, creating a change of state at the comparator output to a high or active state. The signal edge resulting from this change of start represents initial detection of an input pulse. The time of occurrence of this detection edge is substantially independent of the pulse amplitude. To extend the dynamic range of the pulse discriminator, multiple channels, each implemented to handle a distinct range of signal levels, may be included, and combined at their outputs. To improve accuracy for very low-level signals, and to reduce the incidence of false alarms, a separate detection threshold can be used to gate the comparator.

Claims19

Dependent claims

A pulse discriminator having an input and an output, comprising:

a first delay line, a first resistor, a first capacitor, a first adjustable current source, and a first comparator having two inputs and an output;
wherein:
an input signal is provided to the input of the first delay line;
the output of the first delay line is connected to a first input of the first comparator;
the first resistor is connected in parallel across the first capacitor, and is connected between the input of the first delay line and a second input of the first comparator;
and
the adjustable current source is connected to the second input of the first comparator;
and
the output of the first comparator is the output of the pulse discriminator.

6 more elements

A laser rangefinder receiver, comprising means for producing a pulse signal in response to a return and means for detecting the pulse signal, said means for detecting the pulse signal comprising a pulse discriminator, said pulse discriminator comprising:

a first delay line, a first resistor, a first capacitor, a first adjustable current source, and a first comparator having two inputs and an output;
wherein:
an input signal is provided to the input of the first delay line;
the output of the first delay line is connected to a first input of the first comparator;
the first resistor is connected in parallel across the first capacitor, and is connected between the input of the first delay line and a second input of the first comparator;
and
the adjustable current source is connected to the second input of the first comparator;
and
the output of the first comparator is the output of the pulse discriminator.

6 more elements

Dependencies are inferred from the claim text.

Pulse discriminator

Life of this patent

Pulse discriminator

Life of this patent

Abstract

Claims19