S-77100 Datasheet, PDF (16/40 Pages) Seiko Instruments Inc – POWER SEQUENCER

POWER SEQUENCER
S-77100/77101 Series
Rev.1.0_01
As shown in Figur_{__}e_{___}1_{_}4_{_} , after the ON pin of S-77101A(1) changes from "L" to "H", the _{_}o_{__}n_{__}-_{_}s_{_}equence operation is
performed if the OFF pin of S-77101A(2) is either "H" or "L". Similarly, after the OFF pin of S-77101A(2)
changes from "H" to "L", the off-sequence operation is performed if the ON pin of S-77101A(1) is either "H" or
"L". Ther_{_}e_{__}f_{_}o_{_}r_{__}e, due to connecting the control signal pin of the sequence controller, the ON pin of S-77101A(1)
and the OFF pin of S-77101A(2), it is possible to control S-77101A(1) and S-77101A(2) with 1 signal.
Figure 15 shows the connection example.
5 V AUX
DC-DC
LDO
IN OUT _{3.3 V}
S-77101A(1)
3.3 V
0.1 F
VDD
ON
ENBL_A
OFF
ENBL_B
CDLY
ENBL_C
VSS
IN OUT
EN
DC-DC
LDO
IN OUT
EN
DC-DC
LDO
2.5 V
DC-DC
LDO _{1.8 V}
IN OUT
EN
1.5 V
I/O(1)
I/O(2)
LOGIC
S-77101A(2)
3.3 V
0.1 F
VDD
ON
ENBL_A
OFF
ENBL_B
CDLY
ENBL_C
VSS
IN OUT
EN
DC-DC
LDO
IN OUT
EN
DC-DC
LDO
System
2.5 V
DC-DC
LDO _{1.8 V}
IN OUT
EN
1.5 V
I/O(1)
I/O(2)
LOGIC
Remark The ENBL_x pin is CMOS output.
_______
Figure 15 Cascade Connection Example (S-77101A: Reverse Type, with OFF pin)
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