Manual

MAX8621Y/MAX8621Z
Dual Step-Down DC-DC Power-Management ICs
for Portable Devices
______________________________________________________________________________________ 15
UVLO
REF
ON/OFF CONTROL
VOLTAGE
SELECTOR
STEP-DOWN
DC-DC (1, BUCK1)
IN
REF
EN
INP
LX
PGND
FB
STEP-DOWN
DC-DC (2, BUCK2)
IN
REF
EN
INP
LX
PGND
FB
THERMAL
SHUTDOWN
LDO4
OUT
INP
IN
REF
EN
GND
LDO2
OUT
INP
IN
REF
EN
GND
LDO1
OUT
INP
IN
REF
EN
GND
RESET
N
9-BIT SEL
LDO3
OUT
INP
IN
REF
EN
GND
9-BIT SEL
9-BIT SEL
9-BIT SEL
P
N
P
N
IN2
IN3
INPUT
2.6V TO 5.5V
REFBP
GND
DR
ENDR
OUT3
EN3
OUT4
EN4
800kΩ
SEL2
SEL1
EN2
OUT2
FB2
PGND2
LX2
FB1
PGND1
LX1
IN1
RESET
OUT1
R2
115kΩ
R3
150kΩ
R1
150k
Ω
R4
75kΩ
C6
150pF
PWRON
INPUT
2.6V TO 5.5V
PGND2
BUCK2
IN1
14kΩ
1.3Ω, 200mA
C3
4.7µF
C2
4.7µF
C4
0.01µF
C11
2.2µF
C12
2.2µF
800kΩ
C10
4.7µF
C7
2.2µF
C8
150pF
C9
2.2µF
L2
2.2µH
L1
2.2µH
C1
10µF
C5
4.7µF
BUCK1
MAX8621Y
MAX8621Z
Figure 3. Functional Diagram and Typical Application Schematic