A 30–110V Resonant Buck-Boost Power-Bus Charger Achieving 50-A Peak Laser-Current Pulse Generation in 2ns for MHz-Frequency Automotive LiDAR Transmitter

With the advancement of intelligent driving assistance systems, automotive light detection and ranging (LiDAR) has become essential for future vehicles. To ensure the detection accuracy and range of different objects during high-speed driving, the laser diode in the LiDAR transmitter needs tens-ampere of driving current with nano-second pulse-width. There are two types of power supplies for LiDAR transmitters, one is FET-based [1]–[3] and the other is capacitor-discharge-based (CAP-based) [4]–[6]. Due to the high voltage (HV) requirement for the laser diode (DL) and trigger switch (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf>), the former type is usually suitable for lowvoltage (LV) LiDAR systems, which have limited peak laser-current pulse amplitude (l<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">DL, pk</inf>) and limited the detection distance [7] [8]. The CAP-based LiDAR supply is based on a LC resonator formed by a small bus capacitor (C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BUS</inf>) and the stray inductance (L<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">D</inf>) of DL, as shown in Fig. 1. It generates laser current pulse by discharging C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BUS</inf> rather than relying on double-edge trigger and can effectively avoid the device overstress risk. However, the existing CAP-based bus charger have the drawbacks of: 1) Requiring an HV DC source (by an additional boost converter with a bulky output capacitor) [8]; 2) Need of HV source to supplement charge to CBUS by hard charging, causing significant loss due to the large voltage difference; 3) Need of a path resistor (R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</inf>) between VHV source and C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BUS</inf> to reduce the unwanted charge injection from the HV source to the DL and affect the current pulse-width. However, if the RCH is large, the V<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">BUS</inf> recovery time will be long, restricting the upper limit of LiDAR emission frequency. If R<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CH</inf> is too small, excess charges will be injected into DL, widening the pulse-width.