An A/D converter based random bit generator which exploits continuous-time chaos is presented. The chaotic circuit, which is used as the core of the random bit generator generates double-scroll attractor the frequency spectrum of which spans up to 80 MHz. The chaotic circuit was fabricated using a 0: 35 mu m CMOS process and the chip area, excluding pads, is 0.06 mm(2). Power consumption of the integrated chip is 8 mW. Binary data obtained from the presented random bit generator pass the full NIST-800-22 test suite.