SC220 Datasheet, PDF (1/14 Pages) Zarlink Semiconductor Inc – XpressFlow 2020 Ethernet Routing Switch Chipset

SC220
POWER MANAGEMENT
20MHz, 650mA, X-EMI^™-Enabled
Synchronous Step-Down Regulator
Features
 Patented X-EMI^TM Inductor Technology
 Enables Trace Inductors in PC Board Material
 Excellent EMI Performance
 Efficiency up to 90%
 19μA Quiescent Current under Very Light-load
 Wide Input Voltage Range — 2.7V to 5.5V
 Adjustable Output Voltage Down to 1.0V
 Output DC Current — up to 650mA
 High Light-load Efficiency via Automatic PSAVE Mode
 Ultra-fast Transient Response — <1μs
 Temperature Range — -40 to +85°C
 Shutdown Current — 0.1μA (typical)
 Requires Tiny 220nH Inductor
 Requires Only 1μF of Output Capacitance
 External Switching Frequency Synchronization
 Protection Features Including
 Over-Current Protection
 Output Short-Circuit Protection
 Thermal Shutdown Protection
 Offered in SOIC 8 Lead Package
 Lead-free, Halogen-free, and RoHS/WEEE Compliant
Applications
Description
The SC220 is a 20MHz X-EMI™⁽¹⁾-enabled step-down regu-
lator optimized for powering low voltage rails from 2.7 to
5.5V input voltage. X-EMI™ inductor technology enables
inductors to be drawn directly on the PC board. This tech-
nology meets or exceeds the EMI performance of chip
inductors and eliminates the need for discrete inductors.
The SC220 uses a unique constant frequency, self-oscil-
lating control loop architecture to provide excellent
transient performance. Under light load condition, the
device operates in Power Save Mode (PSAVE) and main-
tains a typical quiescent current of 19μA. At moderate to
heavy loads, this part operates in PWM mode with a con-
stant switching frequency of 20MHz. This high switching
frequency offers the advantages of using small and low
cost external components like a 1μF external capacitor
and a small 220nH inductor (including X-EMI^TM PCB trace
inductors).
The device provides adjustable output voltages down to
1.0V and an output current up to 650mA. An EN pin can
be used to synchronize to an external source and includes
de-glitching to reduce noise sensitivity.
 HDTV, Set Top Boxes, Gaming Consoles
 POL Applications
 White Goods
 Automotive (EMI sensitive console applications)
Typical Application Circuit
The SC220 is available in SOIC 8 lead package.
Note 1: Purchase of SC220 includes royalty-free rights to use X-EMI^TM
inductor technology with no additional cost.
V _IN
2.7~5.5V
C _IN
1 μF
P V IN
SW
A V IN
VOUT
SC220
V OUT= 1 .8 V
L, 220nH _{up to 650mA}
R₁
C_OUT
1 μF
E n a b le
EN
PGND
AGND
FB
R₂
January 25, 2012
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