A 110 nA Voltage Regulator System With Dynamic Bandwidth Boosting for RFID Systems

A fully on-chip LDO voltage regulator for remotely powered cortical implants

“…2(b) shows the circuit schematic of the first stage with improved frequency compensation and PSRR. The core of the error amplifier consists of a single-ended telescopic cascode amplifier using C el and M Zb as compensation network, which provides a fast derivative feedback path [4]. However, this compensation technique creates asymmetric left-half plane (LHP) and right-half-plane (RHP) zeros with varying load, which degrades the transient response.…”

“…However, this compensation technique creates asymmetric left-half plane (LHP) and right-half-plane (RHP) zeros with varying load, which degrades the transient response. Dynamic bandwidth boosting proposed in [4] pushes these asymmetric LHP/RHP zeros to higher frequencies when the load current increases, at the cost of increasing ground current. Another solution to avoid these asymmetric zeros consists of canceling the feed-forward path created by the compensation capacitor C e ], using a dedicated active pseudo-differentiator feedback [3] at the cost of increased power consumption.…”

“…In [3] a derivative feedback path guarantees the stability at the expense of additional active circuitry and power consumption (65/lA). Cascode compensation with a dynamic bandwidth boosting is proposed in [4], which guarantees stability over the full range of alternating load current, at the cost of increased power penalty.…”

“…In this paper, we demonstrate that a symmetric single-ended cascode compensation technique can be used to stabilize the regulator over the full range of alternating load current, thereby eluding the need of a dynamic bandwidth boosting technique [4] or any additional active circuitry [3]. In order to minimize the ground current, optimum pole-zero allocation of the loop gain transfer function has been investigated in time domain rather than in the frequency domain.…”

A digitally enhanced LDO voltage regulator for UHF RFID passive tags

“…In order to increase the line modulation factor, [10] makes use of a ripple and temperature stabilizer. Due to GBW parameter plays a major role in load modulation response, the work presented in [11] boosts the tail current of the error amplifier in the LDO, improving the GBW as well as load modulation.…”