Design of an Integrated Scanning Micromirror Driver in BCD Technology

Abstract

The paper presents the design and characterization of a smart IC driver for MEMS scanning micromirrors. The driver integrates in 0.18 μm BCD technology the cascade of the following circuits: resistor-string DAC circuitry for direct interface to a host digital processing unit, a voltage buffer between the DAC and the High-Voltage (HV) stage, and a fully-differential HV amplifier with programmable output common mode. A couple of the designed DACs permits to generate, starting from digital samples, low-voltage analog stimuli. This signal amplified up to 25 V by the HV stage provides the electrostatical actuation of the micromirror. When compared to state-of-the-art the driver offers an integrated solution with good dynamic performances.

Slew-rate Boosted Amplifier Integrated in a Digital Input Driver for Automotive Actuator Control Units

“…With respect to recent works addressing high load values [14,15], the proposed design is the only qualified for harsh automotive applications (ESD 4 kV, -40 to 160°C thermal range) while the others are conceived for consumer applications such as audio line driver and liquid crystal display (LCD) driver. When compared to driver for automotive applications as in [2], it is worth noting that our design has been validated for high automotive temperature range (up to 160°C) while [2] is limited to 125°C. Moreover in [2] a slew-rate of few V/ls on a 100 pF load is obtained at the expenses of a much higher power consumption.…”

“…When compared to driver for automotive applications as in [2], it is worth noting that our design has been validated for high automotive temperature range (up to 160°C) while [2] is limited to 125°C. Moreover in [2] a slew-rate of few V/ls on a 100 pF load is obtained at the expenses of a much higher power consumption.…”

“…However some loads may require also sinusoidal or more complex waveforms, e.g. car's audio speakers or micro-mirror projectors head-up display [1,2]. The ACU design is challenging since harsh environment specifications have to be met such as extended thermal range, from -40 to 160°C, ESD (electrostatic discharge) protection up to 4 kV, protections against under/ over-voltage or over-temperature conditions.…”

An integrated smart driver for inductive loads with self-monitoring/diagnostic capability

“…When the coil current reaches zero, the voltage on LO rises to ground. Equation (5) permits also to estimate the discharge time of the inductor, calculating t 0 when I L reaches zero, see Equation (6). The major constrain when this kind of architecture is used to drive inductive loads is the silicon overheating during the freewheeling phase.…”

“…Moreover, due to the increasing interest in energy efficiency there is a strong research focus on switching-solutions for driving actuators/transducers. With respect to classic solutions of drivers for capacitive and/or resistive loads, as in [4][5][6][7][8], the design of switching drivers for inductive loads requires overcoming more issues because the management of the current, and then the energy stored in the inductor, must be well considered [9][10][11][12][13]. In fact, when inductive loads are driven, it's very important controlling the freewheeling phase.…”