DATASHEET
CA3420 FN1320
Rev 9.00
Oct 4, 2005 0.5MHz, Low Supply Voltage, Low Input Current BiMOS Operational Amplifier
The CA3420 is an integrated circuit operational amplifier that
combines PMOS transistors and bipolar transistors on a
single monolithic chip. The CA3420 BiMOS operational
amplifier features gate protected PMOS transistors in the
input circuit to provide very high input impedance, very low
input currents (less than 1pA). The internal bootstrapping
network features a unique guardbanding technique for
reducing the doubling of leakage current for every 10В°C
increase in temperature. The CA3420 operates at total
supply voltages from 2V to 20V either single or dual supply.
This operational amplifier is internally phase compensated to
achieve stable operation in the unity gain follower
configuration. Additionally, it has access terminals for a
supplementary external capacitor if additional frequency rolloff is desired. Terminals are also provided for use in
applications requiring input offset voltage nulling. The use of
PMOS in the input stage results in common mode input
voltage capability down to 0.45V below the negative supply
terminal, an important attribute for single supply application.
The output stage uses a feedback OTA type amplifier that …