S-8541 Seiko Instruments, S-8541 Datasheet - Page 18

• Manufacturer Part Number: S-8541
• Description: (S-8540 / S-8541) 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
• Manufacturer: Seiko Instruments

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STEP-DOWN, 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8540/8541 Series
Standard Circuits
1. Fixed output voltage (Pch MOS FET)
2. Feed back type (Pch MOS FET)
Caution The above connection diagram and constant will not guarantees successful operation.
One point ground
One point ground
V
IN
V
IN
Perform through evaluation using the actual application to set the constant.
Tr
Tr
SD
SD
C
IN
C
IN
VIN
EXT
EXT
VIN
Power for IC
Power for IC
ON/OFF
ON/OFF
Shu tdo wn
circuit
Shutdown soft start
c irc uit
Seiko Instruments Inc.
s oft start
Figure 14
T riangular wave
oscillation circuit
Figure 13
T riangular wave
oscillation circuit
PWM comparator
PWM c omparator
PW M, PW M/PFM
switching control
circuit
PW M, PW M/PFM
switching control
circuit
V
V
ON/OFF
−
+
ON/OFF
−
+
Phase
comp ensation
circuit
Voltage/current
referenc e
Phase
compe nsation
circuit
Voltage/ current
referenc e
V
Error amplifier
RE F
L
V
Error amplifier
L
RE F
=1.0 V
−
+
=1. 0 V
−
+
CVREF
SENSE
CVREF
125m V
SENSE
+
−
+
−
R
125mV
SEN SE
C
VSS
FB
VOUT
FB
R
SEN SE
VOUT
VSS
Rev.3.2
R
R
A
B
C
C
OUT
OUT
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