C-Load Op Amps Conquer Instabilities – Design Note 107
Kevin R. Hoskins
Introduction
Linear Technology Corporation has taken advantage of
advances in process technology and circuit innovations
to create a series of C-Loadв„ў operational amplifiers that
are tolerant of capacitive loading, including the ultimate,
amplifiers that remain stable driving any capacitive load.
This series of amplifiers has a bandwidth that ranges from
160kHz to 140MHz. These amplifiers are appropriate for
a wide range of applications from coaxial cable drivers to
analog-to-digital converter (ADC) input buffer/amplifiers.
Driving ADCs
Most contemporary ADCs incorporate a sample-and-hold
(S/H). A typical S/H circuit is shown in Figure 1. The hold
capacitor’s (C1) size varies with the ADC’s resolution but
is generally in the range of 5pF to 20pF, 10pF to 30pF and
10pF to 50pF for 8-, 10-and 12-bit ADCs, respectively. gracefully and accurately drive capacitive loads, such as
Linear Technology’s C-Load line of monolithic amplifiers.
Table 1 lists Linear Technology’s unconditionally stable
voltage feedback C-Load amplifiers. Table 2 lists other
voltage feedback C-Load amplifiers that are stable with
loads up to 10,000pF. …