S1F7760X Epson Electronics America, Inc., S1F7760X Datasheet - Page 9

• Manufacturer Part Number: S1F7760X
• Description: Power Supply Ic
• Manufacturer: Epson Electronics America, Inc.

7. FUNCTIONAL DESCRIPTION
7.1 Outline of Operation
S1F77600 Series comprises high-accuracy, low-consumption low-voltage detectors which work at a low voltage.
A detector detects voltage by inputting into a comparator the divided potentials of resistances, R1, R2 and R3,
connected between power supply (V
hysteresis added to prevent malfunction caused by power supply noise because it can detect difference of
potential between V
The detection voltage (-V
found if input voltage rises, are defined by the following formulas:
S1F77600 Series forces output of fixed voltage Hi-Z if operational voltage drops to the lower limit or lower.
Fig.7.1.1 and 7.1.2 show I/O characteristics of P-ch and N-ch open drain outputs, respectively.
Rev.1.4
Detection voltage: -V
Release voltage: +V
Supply Voltage
Output Pch
Open Drain
(OUT)
(V
DD
)
REG
DET
DET
and V
DET
= ((R1+R2+R3)/R3) × V
= ((R2+R3)/R3) × V
Release Voltage (+V
Detection Voltage (-V
Lower Limit of Operational
Voltage
Vss
Release Voltage (+V
Detection Voltage (-V
Lower Limit of Operational
Voltage
V
Fig.7.1.1 I/O characteristics of P-ch open drain
), which is found if input voltage drops, and the release voltage (+V
SS
REF
even if the difference is very small.
REG
) and the reference voltage generated inside IC (V
DET
DET
DET
DET
REF
)
)
REF
)
)
EPSON
......................................................(formula 7.1.1)
..................................................(formula 7.1.2)
S1F7760x Series Technical Manual
HYS Width
Hi-Z
DET
REF
), which is
).
It has
5