SI9912 Datasheet, PDF (1/8 Pages) Vishay Siliconix – Half-Bridge MOSFET Driver for Switching Power Supplies

Si9912
Vishay Siliconix
Half-Bridge MOSFET Driver for Switching Power Supplies
FEATURES
D 4.5- to 5.5-V Operation
D Undervoltage Lockout
D 250-kHz to 1-MHz Switching Frequency
D Shutdown Quiescent Current <5 mA
D One Input PWM Signal Generates Both Drive
D Bootstrapped High-Side Drive
D Operates from 4.5- to 30-V Supply
D TTL/CMOS Compatible Input Levels
D 1-A Peak Drive Current
D Break-Before-Make Circuit
APPLICATIONS
D Multiphase Desktop CPU Supplies
D Single-Supply Synchronous Buck Converters
D Mobile Computing CPU Core Power Converters
D Standard-Synchronous Converters
D High Frequency Switching Converters
DESCRIPTION
The Si9912 is a dual MOSFET high-speed driver with
break-before-make. It is designed to operate in high frequency
dc-dc switchmode power supplies. The high-side driver is
bootstrapped to handle the high voltage slew rate associated
with “floating” high-side gate drivers. Each driver is capable of
switching a 3000-pF load with 60-ns propogation delay and
25-ns transition time. The Si9912 comes with an internal
break-before-make feature to prevent shoot-through current in
the external MOSFETs. A shutdown pin is used to enable the
driver. When disabled, the quiescent current of the driver is
less than 5 mA.
The Si9912 is available in both standard and lead (Pb)-free, 8-pin
SOIC packages for operation over the industrial operation range
(−40_C to 85_C).
FUNCTIONAL BLOCK DIAGRAM AND TRUTH TABLE
V_DD
D1
Level Shift
Undervoltage
SD
IN
BOOT
V_DC
Q₁
OUT_H
V_S
C_BOOT
OUTPUT
TRUTH TABLE
V_S SD IN V_OUTL V_OUTH
LL L
L
L
LLH
L
L
LH L
H
L
V_DD
LHH
L
H
OUT_L
Q₂
HL L
L
L
HL H
L
L
HH L
L
L
HH H
L
H
+
−
V_BBM
GND
Document Number: 71311
S-40134—Rev. B, 16-Feb-04
www.vishay.com
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