SC493 Datasheet, PDF (1/28 Pages) Semtech Corporation – EcoSpeedTM Step-down Controller with I2C Interface

POWER MANAGEMENT
SC493
EcoSpeed^TM Step-down Controller
with I²C Interface
Features
 Input supply voltage range — 3.0V to 28V
 Controller supply voltage range — 3.0V to 5.5V
 All ceramic solution enabled
 I²C interface
 Output voltage fine adjust control
 Output voltage margining
 Supports dynamic voltage transitions via the I²C
interface
 Programmable power-on delay time and soft-start time
 EcoSpeed^TM architecture with pseudo fixed-frequency
adaptive on-time control
 Switching frequency programmable up to 1MHz
 Selectable power save, including ultrasonic
 Non-synchronous start-up into pre-biased loads
 Over-voltage/under-voltage fault protection
 Smart power save
 Power good Output
 Smart drive^TM
 Status register monitoring device operation
 Ultra-thin package — 3 x 3 x 0.6 (mm), 20 pin MLPQ-UT
 Lead-free and halogen-free
 WEEE and RoHS compliant
Description
The SC493 is a synchronous EcoSpeed^TM buck power supply
controller. It features an I²C interface and a bootstrap switch in
a space-saving MLPQ 3X3-20 pin package. The SC493 uses
Semtech’s advanced patented adaptive on-time control archi-
tecture to provide excellent light load efficiency and fast tran-
sient response with small external components.
The I²C interface is used to program the output voltage
offset, the power-on delay time, the soft-start time, the
power save operating mode, and it can enable/disable the
controller. Additionally, a status register provides informa-
tion on device state and faults.
The controller is capable of operating with all ceramic solu-
tions and switching frequencies up to 1MHz. The program-
mable frequency and selectable power save mode offer the
flexibility to optimize the controller for high efficiency and
small size. The power save mode can be enabled to maximize
efficiency over the entire load range (PSAVE), or switched to
ultrasonic mode to set the minimum frequency to the desired
value (UPSAVE). Power save mode can be disabled for opera-
tion in continuous conduction mode at all loads.
Applications
 Printers
 Computer peripherals
Typical Application Circuit
VIN
VDD
R1 R2 R3
EN
PGD
SCL
SDA
EN
PGD
SCL
SDA
A0
A1
A2
SC493
Additional features include output voltage margining,
cycle-by-cycle current limit, output voltage soft-start, over
and under-voltage protection, controller over-tempera-
ture protection, and output voltage soft-shutdown when
disabled. The SC493 also provides a power good output.
RILIM
BST
LX
CBST
DL
Q1
CIN
L
VOUT
R4
Q2
COUT
R5
June 10, 2010
© 2010 Semtech Corporation
US Patent: 7,714,547 B2