S-13A1 Datasheet, PDF (26/74 Pages) Seiko Instruments Inc – HIGH RIPPLE-REJECTION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR

HIGH RIPPLE-REJECTION LOW DROPOUT HIGH OUTPUT CURRENT CMOS VOLTAGE REGULATOR
S-13A1 Series
Rev.2.1_00
 Condition of Application
Input capacitor (C_IN):
Output capacitor (C_L):
2.2 μF or more
2.2 μF or more
Caution
1. Set input capacitor (C_IN) and output capacitor (C_L) as C_IN = C_L.
2. Generally a series regulator may cause oscillation, depending on the selection of external parts.
Confirm that no oscillation occurs in the application for which the above capacitors are used.
 Selection of Input and Output Capacitors (C_IN, C_L)
The S-13A1 Series requires an output capacitor between the VOUT pin and the VSS pin for phase compensation.
Operation is stabilized by a ceramic capacitor with an output capacitance of 2.2 μF or more over the entire temperature
range. When using an OS capacitor, a tantalum capacitor, or an aluminum electrolytic capacitor, the capacitance must
be 2.2 μF or more.
The values of output overshoot and undershoot, which are transient response characteristics, vary depending on the
value of the output capacitor.
The required capacitance for the input capacitor differs depending on the application.
Set the capacitance for input capacitor (C_IN) and output capacitor (C_L) as follows.
• C_IN ≥ 2.2 μF
• C_L ≥ 2.2 μF
• C_IN = C_L
Caution The S-13A1 Series may oscillate if setting the capacitance as C_IN ≥ 2.2 μF, C_L ≥ 2.2 μF, C_IN < C_L.
Define the values by sufficient evaluation including the temperature characteristics under the usage
condition.
 Selection of Capacitor for Inrush Current Limit (C_SS)
(Types in Which Output Voltage is Internally Set of HSOP-8A, HSOP-6, SOT-89-5)
In the S-13A1 Series, the inrush current limit time (t_RUSH) is adjustable by connecting a capacitor for inrush current limit
(C_SS) between the SSC pin and the VSS pin. The time that the output voltage rises to 99% is 0.7 ms typ. when C_SS = 1.0
nF. The S-13A1 Series operates stably even with no C_SS connection (in the state the SSC pin is leaved open).
The recommended value for C_SS is 0 nF^*1 ≤ C_SS ≤ 22 nF, however, define the values by sufficient evaluation including
the temperature characteristics under the usage condition.
*1. In case the S-13A1 Series is used without C_SS connection (C_SS = 0 nF), be sure to leave the SSC pin open and do
not connect it to the VIN pin and the VSS pin.
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