S-L2980_1 Datasheet, PDF (9/23 Pages) Seiko Instruments Inc – HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR

Rev.4.1_00
HIGH RIPPLE-REJECTION AND LOW DROPOUT CMOS VOLTAGE REGULATOR
S-L2980 Series
„ 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 (C_L) can be used in the S-L2980 Series. A capacitor whose ESR is 10Ω or less
can be used.
3. Output Voltage (V_OUT)
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.
4. Line Regulation ⎜⎛ ^ΔVOUT1 ⎟⎞
⎝ ^{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 (ΔV_OUT2)
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 (V_drop)
Indicates the difference between the input voltage (V_IN1) and output voltage when the output voltage
falls to 98 % of the output voltage (V_OUT(E)) by gradually decreasing the input voltage.
V_drop=V_IN1–(V_OUT(E)×0.98)
Seiko Instruments Inc.
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