Integrated Circuits for Programming Flash Memories in Portable Applications

Smart devices such as smart grids, smart home devices, etc. are infrastructure systems that connect the world around us more than before. These devices can communicate with each other and help us manage our environment. This concept is called the Internet of Things (IoT). Not many smart nodes exist that are both low-power and programmable. Floating-gate (FG) transistors could be used to create adaptive sensor nodes by providing programmable bias currents. FG transistors are mostly used in digital applications like Flash memories. However, FG transistors can be used in analog applications, too. Unfortunately, due to the expensive infrastructure required for programming these transistors, they have not been economical to be used in portable applications. In this work, we present low-power approaches to programming FG transistors which make them a good candidate to be employed in future wireless sensor nodes and portable systems. First, we focus on the design of low-power circuits which can be used in programming the FG transistors such as high-voltage charge pumps, low-drop-out regulators, and voltage reference cells. Then, to achieve the goal of reducing the power consumption in programmable sensor nodes and reducing the programming infrastructure, we present a method to program FG transistors using negative voltages. We also present charge-pump structures to generate the necessary negative voltages for programming in this new configuration

A Low-Power Voltage Reference Cell with a 1.5 V Output

A low-power voltage reference cell for system-on-a-chip applications is presented in this paper. The proposed cell uses a combination of standard transistors and thick-oxide transistors to generate a voltage above 1 V. A design procedure is also presented for minimizing the temperature coefficient (TC) of the reference voltage. This circuit was fabricated in a standard 0.35 μm complementary metal-oxide-semiconductor (CMOS) process. It generates a 1.52 V output with a TC of 42 ppm/∘C from −70 ∘C to 85 ∘C while consuming only 1.11 μW

A Regulated Charge Pump with Extremely Low Output Ripple

In this paper, we present a regulated charge pump with extremely low output ripple (<1 mV) that can be used for accurate programming of nonvolatile memory. We present a technique to include a low-drop-out regulator inside the charge-pump regulation loop to reduce the ripple. This charge pump was fabricated in a 0.35 μ m standard CMOS process. The die area of this charge pump is 0.163 mm 2 . While operating from a 2.5 V supply, this charge pump generates regulated voltages up to 10 V

A Regulated Charge Pump with Extremely Low Output Ripple

Abstract: In this paper, we present a regulated charge pump with extremely low output ripple (\u3c1 mV) that can be used for accurate programming of nonvolatile memory. We present a technique to include a low-drop-out regulator inside the charge-pump regulation loop to reduce the ripple. This charge pump was fabricated in a 0.35 µm standard CMOS process. The die area of this charge pump is 0.163 mm2 . While operating from a 2.5 V supply, this charge pump generates regulated voltages up to 10 V