RT9618_11 Datasheet, PDF (1/12 Pages) Richtek Technology Corporation – Synchronous-Rectified Buck MOSFET Drivers

RT9618/A
Synchronous-Rectified Buck MOSFET Drivers
General Description
The RT9618/A are high frequency, dual MOSFET drivers
specifically designed to drive two power N-MOSFETs in a
synchronous-rectified buck converter topology. The drivers
combined with Richtek’ s series of Multi-Phase Buck PWM
controller form a complete core-voltage regulator solution
for advanced micro-processors.
The RT9618/A drive both the lower/upper gate in a
synchronous-rectifier bridge with 12V. This drive-voltage
flexibility provides the advantage of optimizing applications
involving trade-offs between switching losses and
conduction losses.
RT9618A has longer UGATE/LGATE deadtime which can
drive the MOSFETs with large gate RC value, avoiding the
shoot-through phenomenon. RT9618 is targeted to drive
low gate RC MOSFETs and performs better efficiency.
The output drivers in the RT9618/A can efficiently switch
power MOSFETs at frequency up to 500kHz. Switching
frequency above 500kHz has to take into account the
thermal dissipation of the packages. RT9618/A are capable
to drive a 3nF load with a 30ns rise time. RT9618/A
implements bootstrapping on the upper gate with an
external capacitor and an embedded diode. This reduces
implementation complexity and allows the use of higher
performance, cost effective N-MOSFETs. Adaptive shoot-
through protection is integrated to prevent both MOSFETs
from conducting simultaneously.
Pin Configurations
(TOP VIEW)
BOOT
PWM
2
OD
3
VCC
4
8 UGATE
7 PHASE
6 PGND
5 LGATE
SOP-8
BOOT ¹
8 UGATE
PWM ²
OD ³
VCC 4
GND
9
7 _PHASE
6 _PGND
5 LGATE
WDFN-8L 3x3
DS9618/A-06 April 2011
Features
z Drives Two N-MOSFETs
z Adaptive Shoot-Through Protection
z Embedded Boot Strapped Diode
z Support High Switching Frequency
z Fast Output Rise Time
z Small SOP-8 and 8-Lead WDFN Package
z Tri-State Input for Bridge Shutdown
z Supply Under Voltage Protection
z Upper MOSFET Direct Shorted Protection
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Core Voltage Supplies for Desktop, Motherboard CPU
z High Frequency Low Profile DC-DC Converters
z High Current Low Voltage DC-DC Converters
Ordering Information
RT9618/A
Package Type
S : SOP-8
QW : WDFN-8L 3x3
Lead Plating System
P : Pb Free
G : Green (Halogen Free and Pb Free)
Note :
Long Dead Time
Short Dead Time
Richtek products are :
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area.
www.richtek.com
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