HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-L2980 Series
Rev.4.1_00
Technical Terms
1. Low Dropout Voltage Regulator
The low dropout voltage regulator is a voltage regulator whose dropout voltage is low due to its built-in
low on-resistance transistor.
2. Low ESR
Low ESR means the Equivalent Series Resistance of a capacitor is small. The low ESR ceramics
output capacitor (CL) can be used in the S-L2980 Series. A capacitor whose ESR is 10Ω or less
can be used.
3. Output Voltage (VOUT
)
The accuracy of the output voltage is ensured at ± 2.0 % under the specified conditions of fixed input
voltage*1, fixed output current, and fixed temperature.
*1. Differs depending upon the product.
Caution If the above conditions change, the output voltage value may vary and exceed the
accuracy range of the output voltage. Refer to the “ Electrical Characteristics” and
“ Typical Characteristics” for details.
ΔVOUT1
⎛
⎜
⎞
⎟
4.Line Regulation
ΔVIN • VOUT
⎝
⎠
Indicates the dependency of the output voltage on the input voltage. That is, the value shows how
much the output voltage changes due to a change in the input voltage with the output current remaining
unchanged.
5. Load Regulation (ΔVOUT2
)
Indicates the dependency of the output voltage on the output current. That is, the value shows how
much the output voltage changes due to a change in the output current with the input voltage remaining
unchanged.
6. Dropout Voltage (Vdrop
)
Indicates the difference between the input voltage (VIN1) and output voltage when the output voltage
falls to 98 % of the output voltage (VOUT(E)) by gradually decreasing the input voltage.
Vdrop=VIN1–(VOUT(E)×0.98)
9
Seiko Instruments Inc.
SII [ SEIKO INSTRUMENTS INC ]
