Preliminary
RT9603
Synchronous-Rectified Buck MOSFET Drivers
General Description
Features
l Drives Two N-Channel MOSFETs
l Adaptive Shoot-Through Protection
l Supports High Switching Frequency
- Fast Output Rise Time
The RT9603 is a high frequency, dual MOSFET drivers
specifically designed to drive two power N-Channel
MOSFETs in a synchronous-rectified buck converter
topology. The device combined with the RT924x series
of multi-phase PWM controllers and MOSFETs form a
complete core voltage regulator solution for advanced
microprocessors.
- Propagation Delay 40ns
l Tri-State Input for Bridge Shutdown
l Supply Over-Voltage Protection above Maximum
Voltage Rating
The output drivers in the RT9603 can efficiently switch
power MOSFETs at frequencies up to 500kHz. It shall be
taken into account the thermal consideration when the
switching frequency above 500kHz. Each driver is
capable of driving a 3nF load in 30/40ns rise/fall time with
fast propagation delay from input transition to the gate of
the power MOSFET. The device implements boot-
strapping on the upper gate with only an external capacitor
and a diode required. This reduces implementation
complexity and allows the use of higher performance,
cost effective N-Channel MOSFETs.
l Supply Under-Voltage Protection
l Upper MOSFET Direct Shorted Protection
l Small SOP-8 Package
Applications
l Core Voltage Supplies for Intel PentiumÒ 4, AMDÒ
AthlonTM Microprocessors
l High Frequency Low Profile DC-DC Converters
l High Current Low Voltage DC-DC Converters
l IA Equipments
Both drivers incorporate adaptive shoot-through protect-
ion to prevent upper and lower MOSFETs from conduct-
ing simultaneously and shorting the input supply.
Pin Configurations
An unique feature of the RT9603 driver is the addition of
over-voltage protection in the event of upper MOSFET
direct shorted before power-on. The RT9603 detects the
fault condition during initial start-up, the internal power-
on OVP sense circuitry will rapidly drive the output lower
MOSFET on before the multi-phase PWM controller takes
control. As a result, the input supply will latch into the
shutdown state, thereby prevent the processor from
damaged.
(TOP VIEW)
BST
IN
8
7
6
5
DRVH
SW
2
3
4
NC
PGND
DRVL
VCC
SOP-8
Ordering Information
RT9603
Package Type
S : SOP-8
Operating Temperature Range
C : Commercial Standard
DS9603-00 November 2003
www.richtek.com
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