SC420A
High Speed, Combi-Sense
TM
, Synchronous
Power MOSFET Driver for Mobile Applications
POWER MANAGEMENT
Description
The SC420A is a cost effective Dual MOSFET Driver, in-
corporating Semtech’s patented Combi-Sense
TM
technol-
ogy, designed for switching High and Low side Power
MOSFETs in Step-down Switching regulators. A 30ns max
POWER MANAGEMENT
propagation delay from input transition to the gate of
the power FET’s guarantees operation at high switching
frequencies. Internal overlap protection circuit prevents
shoot-through from Vin to GND in the main and synchro-
nous MOSFETs.
reducing switching losses at high frequencies without
causing thermal stress on the driver.
Features
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High efficiency
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Shutdown mode for increased power saving
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Fast rise and fall times (10ns typical with 3000pF
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u
u
load)
5V gate drive
Ultra-low (<30ns) propagation delay (BG going low)
Adaptive and programmable non-overlapping gate
drives provide shoot-through protection
Floating top drive switches up to 27V
High frequency operation allows use of small
inductors and low cost ceramic capacitors
Under-voltage lockout
Low quiescent current
MLP packaging provides superior thermal perfor-
mance in a small footprint
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High current drive capability allows fast switching, thus
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u
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The high voltage CMOS process allows operation up to
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27 Volts, making the SC420A suitable for adaptor pow-
ered applications. Under-voltage-lockout and over-tem-
perature shutdown features are included for proper and
safe operation. The SC420A is offered in a space saving
MLP-12 package.
Applications
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High efficiency portable and notebook computers
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Battery powered applications
Conceptual Application Circuit
VIN2
VIN
D1
M1
VIN
PWM
FB
CO
VIN2
VIN
TG
BST
Combi-Sense
TM
Controller IC
GND
CS- CS+
SC420A
EN
DRN
BG
CDELAY
VPN
CBST
L1
VOUT
EN
M2
RVPN
CVPN
CDELAY
CL
Figure 1
Revision: April 1, 2004
1
United States Patent No. 6,441,597
www.semtech.com
SEMTECH [ SEMTECH CORPORATION ]
