A 7V-to-30V-Supply 190A/µs Regulated Gate Driver in a 5V CMOS-Compatible Process

Abstract

The growing markets of electronic components in automotive electronics, LCD/LED drivers and TV sets lead to an extensive demand of high-voltage integrated circuits (HVICs), which are normally built by HV-MOSFETs. These HV-MOSFET devices generally occupy large die areas and operate at low speed due to large parasitic capacitance and small transconductance (gm). There are two types of HV-MOSFET devices, namely, thick-gate and thingate oxide devices. Thick-gate oxide devices can sustain a high gate-to-source voltage, VGS, but suffer from a reduced gm, poor threshold voltage VT control in production and higher cost due to the need of extra processing steps. Thin-gate devices have a larger gm, smaller parasitic capacitance, less processing steps and a lower cost. These properties make the thingate HV-MOSFETs attractive, though they face severe limitation on VGS swing. There are two main concerns when thin-gate HV-MOSFETs are used. The first is how to achieve high current driving capability to drive capacitive loads in high-voltage (HV) application, whereas the second is how to protect the thin-gate oxide from HV stress breakdown. For current-driving capability, Bales (Bales, 1997) proposed a class-AB amplifier using bipolar technology which consumes a high quiescent current and is expensive due to a large die area and complicated masking. Lu & Lee (Lu & Lee, 2002) proposed a CMOS class-AB amplifier which can only drive around 6mA and does not meet the driver requirements of large and fast current responses (Hu & Jovanovic, 2008). Mentze et al. (Mentze et al., 2006) proposed a HV driver using pure low-voltage (LV) devices but this architecture requires an expensive silicon-on-insulator (SOI) process to sustain substrate breakdown in HV application. Tzeng & Chen (Tzeng & Chen, 2009) proposed a driver that consumes a large die area with all transistors inside the circuit being HV transistors. On the other hand, transistor reliability becomes a serious issue in HV thin-gate oxide transistor circuits. Chebli et al. (Chebli et al., 2007) proposed the floating gate protection technique. The voltage range under protection will change according to the ratio of capacitors and the HV supply, VDDH. This technique, however, cannot limit the voltage across the nodes of gate and source well when the variation of the supply voltage is large. Riccardo et al. (Riccardo et al., 2001) proposed a method which requires an extra Zener diode to protect the thin-gate oxide transistors, so a special process and higher cost are incurred. Declercq et al. (Declercq et al., 1993) suggested a HV-MOSFET op-amp driver with a clamping circuit to protect the thin-