sccsp900842/r2 Freescale Semiconductor, Inc, sccsp900842/r2 Datasheet - Page 11

• Manufacturer Part Number: sccsp900842/r2
• Description: Sc900842, Buck-boost Dc-dc And Ldo Power Management Ic
• Manufacturer: Freescale Semiconductor, Inc

TYPICAL CIRCUIT
schematic for a typical application. A 1-µH inductor with
saturation current rating over 2.5 A is recommended for the
SM DC/DC converter. The inductor series DC resistance
(DCR) should be less than 55 mohm to achieve good
efficiency and a low drop-out voltage. If a smaller inductance
is used, the 900842 may become unstable under line and
load transients and the transient response time may be
affected. The 900842 is designed for ceramic capacitor in its
input and output filters. The input filter capacitor, CIN33,
reduces the voltage ripple on VIN, by providing the AC
current drawn to the M1 switch during the first part of each
Analog Integrated Circuit Device Data
Freescale Semiconductor
Figure 5, 900842 Typical
VREGOUT
C
CLK26M
CORE
VIN1P8
STTS
ISNS
EN
C
BGBYP
LDO
Logic
Regulator
Applications, shows the
Shutdown
Thermal
BGBYP
Bandgap
and Ref
Figure 5. 900842 Typical Applications
TYPICAL APPLICATIONS
C
AGND
IN33
Controller
AVIN
Buck or
Boost
switching cycle. A 10 µF ceramic capacitor should be used
for CIN33 as close as possible to the PVIN1 and PGND pins
of the IC. The triangular AC component of the inductor
current passes through the output filter capacitor, CO33,
which reduces the output voltage ripple and maintains a
constant output voltage during load and line transients. A
22 µF ceramic capacitor should be used for CO33 as close as
possible to the VOUTP and PGND pins. A 100 nF ceramic
capacitor should be used for CBGBYP as close as possible
to the BGBYP and AGND pins. A 1.0 µF ceramic capacitor
should be used for CCORE as close as possible to the
VREGOUT and AGND pins. Ceramic capacitor types such as
X5R and X7R are recommended.
V
IN
M
M
1
2
PGND
PVIN1
SM DC/DC Converter
M
M
4
3
FUNCTIONAL PIN DESCRIPTION
PVIN2
VOUTP
VOUTPFB
VSW1P
VSW1FB
VSW2FB
VSW2P
VOUTMFB
TYPICAL APPLICATIONS
L
33
C
Load
900842
O33
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