Circuit for background light suppression

US11977163B2 · kind B2 · utility

Assignees

• IFM Electronic GmbH · US
• PMD TECHNOLOGIES AG · DE

Inventors

• Peter Runtemund · Siegen, DE
• Carl Philip Heising · Wilnsdorf, DE

Key dates

• Filing date: Dec 9, 2021
• Grant date: May 7, 2024
• Expiry date: Dec 9, 2041

Classification

• Technology area (CPC G): Physics
• CPC primary: G01S17/36
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Described is a circuit for background light suppression (SBI, 500) for a light propagation time sensor (22) which operates according to a phase measuring principle and the light propagation time pixels of which have integration nodes or diodes (Ga, Gb, diode_a, diode_b) for the accumulation of charges, having an input stage (50), an operational amplifier (OP) and an SBI current source (SQ), wherein the input phase (50) has bypass and common mode circuits (SBP, SVcm) via which signals of the integration nodes (Ga, Gb, diode_a, diode_b) are guided to the operational amplifier (OP) and via which the operational amplifier (OP) can be switched to a maximum detection or common mode operation, wherein the operational amplifier (OP) is designed such that based on the signals of the integration nodes (Ga, Gb, diode_a, diode_b) switched by the input stage (50) to the operational amplifier (OP), a gate voltage (gate_cs) is generated for the SBI current source (SQ), wherein the SBI current source (SQ) has a first current source (SQ1) for the maximum detection operation and a second and third current source (SQ2a, SQ2b) for the common mode operation wherein the current sources (SQ1, SQ2a, SQ2b)…