S1135 Datasheet, PDF (21/48 Pages) Seiko Instruments Inc – HIGH RIPPLE-REJECTION LOW DROPOUT

HIGH RIPPLE-REJECTION LOW DROPOUT MIDDLE OUTPUT CURRENT CMOS VOLTAGE REGULATOR
Rev.2.2_00
S-1135 Series
3. ON / OFF pin
This pin starts and stops the regulator.
When the ON / OFF pin is set to OFF level, the entire internal circuit stops operating, and the built-in P-channel MOS
FET output transistor between the VIN and VOUT pins is turned off, reducing current consumption significantly.
Since the S-1135 Series A / B / E / F type has a built-in discharge shunt circuit to discharge the output capacitance,
the VOUT pin is forcibly set to V_SS level. In the S-1135 Series C / D / G / H type, the VOUT pin is set to V_SS level
through several hundred kΩ internal divided resistors between the VOUT and VSS pins. Note that the current
consumption increases when a voltage of 0.3 V to 1.0 V (Ta = 25°C) is applied to the ON / OFF pin.
The ON / OFF pin is configured as shown in Figures 21 and 22. In the S-1135 Series A / C / E / G type, the ON
/ OFF pin is internally pulled up to the VIN pin or pulled down to the VSS pin in the floating status, so the VOUT pin is
set to the V_SS level. In the S-1135 Series B / D / F / H type, the ON / OFF pin is not internally pulled up or pulled
down, so do not use the ON / OFF pin in the floating status. When not using the ON / OFF pin, connect it to the VIN
pin in the product B / D type, and connect it to the VSS pin in the F / H type.
Table 11
Product Type ON / OFF Pin
Internal Circuit
VOUT Pin Voltage
Current Consumption
A / B / C / D “H”: ON
Operate
Set value
I_SS1^*1
A / B / C / D “L”: OFF
Stop
V_SS level
I_SS2
E/F/G/H
E/F/G/H
“H”: OFF
“L”: ON
Stop
Operate
V_SS level
Set value
I_SS2
I_SS1^*1
*1. Note that the IC’s current consumption increases as much as current flows into the pull-up / pull-down
resistor when; the ON / OFF pin is connected to the VIN pin in the A / C type, the ON / OFF pin is
connected to the VSS pin in the E / G type (Refer to Figure 21).
(1) S-1135 Series A / C / E / G type
(2) S-1135 Series B / D / F / H type
VIN
VIN
E / G type
ON / OFF
A / C type
VSS
Figure 21
ON / OFF
VSS
Figure 22
Seiko Instruments Inc.
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