  We present the single event effect (SEE) tolerance of a mixed-signal
application-specific integrated circuit (ASIC) developed for a charge-coupled
device camera onboard a future X-ray astronomical mission. We adopted proton
and heavy ion beams at HIMAC/NIRS in Japan. The particles with high linear
energy transfer (LET) of 57.9 MeV cm^{2}/mg is used to measure the single event
latch-up (SEL) tolerance, which results in a sufficiently low cross-section of
sigma_{SEL} < 4.2x10^{-11} cm^{2}/(IonxASIC). The single event upset (SEU)
tolerance is estimated with various kinds of species with wide range of energy.
Taking into account that a part of the protons creates recoiled heavy ions that
has higher LET than that of the incident protons, we derived the probability of
SEU event as a function of LET. Then the SEE event rate in a low-earth orbit is
estimated considering a simulation result of LET spectrum. SEL rate is below
once per 49 years, which satisfies the required latch-up tolerance. The upper
limit of the SEU rate is derived to be 1.3x10^{-3}events/sec. Although the SEU
events cannot be distinguished from the signals of X-ray photons from
astronomical objects, the derived SEU rate is below 1.3% of expected non-X-ray
background rate of the detector and hence these events should not be a major
component of the instrumental background.
