S-8540A15FN-IAAT2Z Datasheet, PDF (18/36 Pages) Seiko Instruments Inc – SWITCHABLE SWITCHING REGULATOR CONTROLLER

STEP-DOWN, 600 kHz PWM CONTROL or PWM/PFM SWITCHABLE SWITCHING REGULATOR CONTROLLER
S-8540/8541 Series
Rev.4.0_01
 Standard Circuits
1. Fixed output voltage (Pch MOS FET)
R_SENSE
L
SENSE
Tr
VIN ^{Power for IC Triangular wave}
oscillation circuit
+
EXT
PWM comparator
−
Phase
compensation
circuit
−
125mV _VOUT
+
V_IN
SD
C_IN
PWM, PWM/PFM
switching control
circuit
Error amplifier
−
+
C_OUT
Shutdown soft start
circuit
V_REF=1.0 V
Voltage/current
reference
VSS
One point ground
ON/OFF
V_ON/OFF
CVREF
Figure 13
2. Feed back type (Pch MOS FET)
R_SENSE
L
SENSE
Tr
VIN ^{Power for IC Triangular wave}
oscillation circuit
+
−
EXT
PWM comparator
Phase
compensation
circuit
125mV
VOUT
V_IN
SD
−
+
Error amplifier
CFB
RA
PWM, PWM/PFM
−
CIN
switching control
circuit
+
FB
Shutdown soft start
circuit
V_REF=1.0 V
Voltage/current
reference
VSS
RB
COUT
One point ground
ON/OFF
VON/OFF
CVREF
Figure 14
Caution The above connection diagram and constant will not guarantees successful operation.
Perform through evaluation using the actual application to set the constant.
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