S-19244A12A-E8T1U Datasheet, PDF (31/68 Pages) Seiko Instruments Inc – CMOS VOLTAGE REGULATOR WITH SOFT-START FUNCTION

FOR AUTOMOTIVE 125°C OPERATION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR WITH SOFT-START FUNCTION
Rev.3.0_00
S-19244xxxA Series
8. 1 S-19244xxxA Series A / B / C / D type
By charging the built-in capacitor via the built-in constant current source, t_SS = 1.0 ms typ. is generated.
8. 2 S-19244xxxA Series E / F / G / H type
t_SS can be adjusted by the external capacitor (C_SS) connected between the SSC pin and the VSS pin, and is
calculated by using the following calculation.
t_SS [ms] = Soft-start coefficient^*1 [ms / nF] × C_SS [nF] + t_D0^*2 [ms]
*1. It is determined by charging the built-in constant current (approx. 2.1 μA) to C_SS.
*2. The delay time of internal capacitance.
When the C_SS value is sufficiently large, the t_D0 value can be disregarded. When the ON / OFF pin is set to OFF,
the electrical charge charged in C_SS is discharged by the transistor of the discharge shunt circuit.
Table 28 Soft-start Coefficient [ms / nF]
Operation Temperature
Min.
Typ.
T_j = +150°C
T_j = +125°C
T_j = +25°C
T_j = −40°C
0.391
0.393
0.436
0.467
0.528
0.534
0.574
0.604
Max.
0.691
0.690
0.704
0.717
Table 29 Delay Time of Internal Capacitnace (t_D0)
Operation Temperature
Min.
Typ.
Max.
T_j = −40°C to +150°C
0.032 ms
0.047 ms
0.108 ms
Caution
The above calculation will not guarantee successful operation. Perform thorough evaluation using
the actual application including the temperature characteristics under the actual usage conditions
to determine C_SS capacitance. Refer to " Condition of Application" and " Characteristics (Typical
Data)" for details.
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