A 30 μ W CMOS bandgap reference featuring a 1.5-6 mA output driving current and a Miller-effect startup circuit

Abstract

We present a pure CMOS bandgap voltage reference with a low quiescent current and high output current driving capability. The circuit sources a driving current of up to 1.5 mA with the reference voltage kept above 98.5% of its designated 1.2 V, and up to 6 mA before the voltage drops to 90%. The circuit achieves a very low supply current of 13 μ A, a low power of 30 μ W, a line regulation of ± 2.5 mV / V and a load regulation of ± 7 mV / mA. The reference is implemented in a 1 μ m pure CMOS process with Vtn ≈ | Vtp | ≈ 0.7 V at 25 {ring operator} C using substrate pnp. A startup circuit, which shuts down itself after a controlled delay using Miller effect, is also introduced. By utilizing the body effect of the input transistors, the turn-on threshold of the startup circuit is raised to about 1 V, making it a perfect match for the reference architecture. Silicon measurements are in good agreement with simulations. © 2009 Elsevier Ltd. All rights reserved.