S1172 Datasheet, PDF (12/35 Pages) Seiko Instruments Inc – HIGH RIPPLE-REJECTION LOW DROPOUT

HIGH RIPPLE-REJECTION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR
S-1172 Series
Rev.2.2_01
 Explanation of Terms
1. Low dropout voltage regulator
This voltage regulator has the low dropout voltage due to its built-in low on-resistance transistor.
2. Output voltage (V_OUT)
The accuracy of the output voltage is ensured at ±1.0% or ±15 mV^*2 under the specified conditions of fixed input
voltage^*1, fixed output current, and fixed temperature.
*1. Differs depending on the product.
*2. When V_OUT < 1.5 V : ±15 mV, when 1.5 V ≤ V_OUT : ±1.0%
Caution
If the above conditions change, the output voltage value may vary and exceed the accuracy
range of the output voltage. Refer to “ Electrical Characteristics” and “ Characteristics
(Typical Data)” for details.
3.
Line regulation
 ^ΔVOUT1
ΔV_IN•V_OUT


Indicates the dependency of the output voltage against the input voltage. That is, the value shows how much the
output voltage changes due to a change in the input voltage after fixing output current constant.
4. Load regulation (ΔV_OUT2)
Indicates the dependency of the output voltage against the output current. That is, the value shows how much the
output voltage changes due to a change in the output current after fixing output current constant.
5. Dropout voltage (V_drop)
Indicates the difference between input voltage (V_IN1) and the output voltage when; decreasing input voltage (V_IN)
gradually until the output voltage has dropped out to the value of 98% of output voltage (V_OUT3), which is at
V_IN = V_OUT(S) + 1.0 V or 5.5 V.
V_drop = V_IN1 − (V_OUT3 × 0.98)
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Seiko Instruments Inc.