SC4510 Datasheet, PDF (1/16 Pages) Semtech Corporation – High Performance Synchronous Buck Controller With Reference Tracking

POWER MANAGEMENT
SC4510
High Performance Synchronous Buck
Controller With Reference Tracking
Description
Features
The SC4510 can be configured as a synchronous buck
convertor capable of sourcing and sinking current from load
without losing output regulation. The output can be set to
track an internal reference or an external voltage. The
actual reference used by the error amplifier is buffered
and brought out as a reference. It is the ideal choice for
externally referenced or tracking buck convertors such as
those for DDR memory applications.
The controller is also designed for point of use DC-DC
convertors with 2.5-16V power sources with a Vcc of 4.5V
or higher. Soft start, current limit, programmable oscillator
and external compensation functions are provided to
ensure high degree of integration and low external
component count. Semetch’s patented Combi-Sense™
technique is utilised for lossless current sening and
maximising efficiency. Both high and low side MOSFET
drivers are built in and rated for substantial peak currents
to minimise switching losses. The SC4510 is offered in a
space saving TSSOP-20 package.
Typical Application Circuit
u Synchronous buck operation with current sink or
source without loss of regulation
u Output can track internal or external reference
u Buffered reference output from external reference
u Combi-Sense mode lossless current sensing
u 2.5V to 16V operation with 4.75V minimum V_CC
u Direct drive for high side N-channel MOSFETs with
diode and capacitor bootstrap
u Undervoltage lockout, Soft Start, Enable and Power
Good functions
u Fast transient response with external compensation
u Current mode control with transconductance error
amplifier
u Programmable oscillator frequency with external sync
Applications
u Externally referenced buck convertors
u DDR memory terminators
u Point of use power supplies
VIN
15V MAX
C1
C2
D1
RTN
C4 C5
SYNC
R2 R3 C6
Q1
R1
L1
VOUT
C3
0.5V MIN
Q2
R4
C7
RTN
SC4510
U1
C8
INT REF
IN+
EXT REF
C10
C11
C12
C13
R5
R6
R7
C9
PGOOD
REFOUT
Revision: Jan 07, 2005
United States Patent #6,441,597
1
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