S-19243A12A-E8T1U Datasheet, PDF (28/74 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
S-19243xxxA Series
Rev.3.0_00
3. ON / OFF pin
The ON / OFF pin controls the internal circuit and the output transistor in order to start and stop the regulator. When
the ON / OFF pin is set to OFF, the internal circuit stops operating and the output transistor between the VIN pin
and the VOUT pin is turned off, reducing current consumption significantly.
Note that the current consumption increases when a voltage of 0.6 V to V_IN − 0.3 V is applied to the ON / OFF pin.
The ON / OFF pin is configured as shown in Figure 30 and Figure 31.
3. 1 S-19243xxxA Series A / C / E / G type
Since the ON / OFF pin is internally pulled down to the VSS pin in the floating status, the VOUT pin is set to the
V_SS level.
Refer to " Electrical Characteristics" for the ON / OFF pin current.
3. 2 S-19243xxxA Series B / D / F / H type
Since the ON / OFF pin is neither pulled down nor pulled up, do not use these types in the floating status. When
not using the ON / OFF pin, connect it to the VIN pin.
Table 28
Product Type
A/B/C/D
E/F/G/H
A/B/C/D
E/F/G/H
ON / OFF Pin
"H" : ON
"L" : OFF
Internal Circuit
Operate
Stop
VOUT Pin Voltage
Constant value^*1
Pulled down to V_SS^*3
Current Consumption
I_SS1^*2
I_SS2
*1. The constant value is output due to the regulating based on the set output voltage value.
*2. Note that the IC's current consumption increases as much as current flows into the pull-down resistor when
the ON / OFF pin is connected to the VIN pin and the S-19243xxxA Series A / C / E / G type is operating (refer
to Figure 30).
*3. The VOUT pin voltage is pulled down to V_SS due to the discharge shunt circuit (R_LOW = 100 Ω typ.), the
feedback resistors (R_s and R_f) and a load.
VIN
VIN
ON / OFF
VSS
Figure 30 S-19243xxxA Series
A / C / E / G type
ON / OFF
VSS
Figure 31 S-19243xxxA Series
B / D / F / H type
28