S-818_1 Datasheet, PDF (11/32 Pages) Seiko Instruments Inc – LOW DROPOUT CMOS VOLTAGE REGULATOR

Rev.2.1_00
LOW DROPOUT CMOS VOLTAGE REGULATOR
S-818 Series
4. Load regulation (∆V_OUT3)
Load regulation indicates the output current dependence of output voltage. The value shows how much
the output voltage changes due to the change of the output current when the input voltage is kept
constant.
5. Dropout voltage (V_drop)
Let V_IN1 be an input voltage where the output voltage falls to the 98 % of the actual output voltage
(V_OUT(E)) when gradually decreasing input voltage. The dropout voltage is the difference between the V_IN1
and the resultant output voltage defined as following equation.
V_drop=V_IN1−(V_OUT(E)×0.98)
6. Temperature coefficient of output voltage  ^∆VOUT 
 ^{∆Ta • VOUT} 
The output voltage lies in the shaded area in the whole operating temperature shown in Figure 11 when
the temperature coefficient of the output voltage is ±100 ppm/°C.
V_OUT [V]
+0.28mV/°C
V_OUT(E)^*1
−0.28mV/°C
−40
25
85
Ta [°C]
*1. The value of the output voltage measured at 25°C.
Figure 11 Temperature coefficient of output voltage (Ex. Typ. product for S-818A28A)
Temperature change ratio for output voltage [mV/°C] is calculated by using the following equation.
[ ] [ ] [ ] ^∆VOUT mV/°C ^*1 = VOUT(S) V ^*2 × ^∆VOUT ppm/°C ^*3 ÷ 1000
∆Ta
∆Ta • VOUT
*1. Temperature change ratio for output voltage
*2. Specified output voltage
*3. Output voltage temperature coefficient
Seiko Instruments Inc.
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