A temperature independent trimmable current source

Author

Shah, Sunay ; Collins, Steve

Author_Institution

Dept. of Eng. Sci., Oxford Univ., UK

Volume

1

fYear

2002

fDate

6/24/1905 12:00:00 AM

Abstract

A non-volatile floating-gate MOSFET based trimmable current cell suitable for use in a current steering DAC and implemented in 0.35 μm, 3.3 V CMOS technology is presented. The current source can be programmed to an accuracy corresponding to 12-bit resolution using either hot electron injection to add charge to the floating-gate or hot hole injection to remove charge. The output current from the circuit can be adjusted by 40% to overcome the relatively large variations in output current which arise when a MOSFET is biased with a low gate overdrive voltage (Vgs-Vt). This allows the circuit to be designed around the temperature invariant region to give an output which is temperature independent over a large trimming range. This circuit could therefore be ideally suited to operate in the uncertain thermal environment created when a DAC is incorporated within a system on chip.

Keywords

CMOS integrated circuits; application specific integrated circuits; constant current sources; digital-analogue conversion; hot carriers; 0.35 micron; 12 bit; 3.3 V; CMOS technology; current steering DAC; gate overdrive voltage; hot electron injection; hot hole injection; nonvolatile floating-gate MOSFET based cell; output current; system on chip; temperature independent trimmable current source; temperature invariant region; trimming range; uncertain thermal environment; CMOS technology; Decoding; Digital control; Hot carriers; Low voltage; MOSFET circuits; Nonvolatile memory; Secondary generated hot electron injection; System-on-a-chip; Temperature;

fLanguage

English

Publisher

ieee

Conference_Titel

Circuits and Systems, 2002. ISCAS 2002. IEEE International Symposium on

Print_ISBN

0-7803-7448-7

Type

conf

DOI

10.1109/ISCAS.2002.1009940

Filename

1009940