RT9209 RICHTEK [Richtek Technology Corporation], RT9209 Datasheet - Page 4

• Manufacturer Part Number: RT9209
• Description: Synchronous Buck PWM DC-DC with Enable & PGOOD
• Manufacturer: RICHTEK [Richtek Technology Corporation]

RT9209/A
Functional Pin Description
FB (Pin1)
This pin is connected to the PWM converter's output divider.
This pin also connects to internal PWM error amplifier
inverting input and protection monitor.
VCC (Pin 2)
This is the main bias supply for the RT9209/A. This pin
also provides the gate bias charge for the lower MOSFETs
gate. The voltage at this pin monitored for power-on reset
(POR) purpose. This pin is also the internal 6.5V regulator
output powered from BOOT pin when BOOT pin is directly
powered from ATX 12V.
LGATE (Pin 3)
Connect LGATE to the PWM converter's lower MOSFET
gate. This pin provides the gate drive for the lower
MOSFET.
GND (Pin 4)
Signal and power ground for the IC. All voltage levels are
measured with respect to this pin.
Absolute Maximum Ratings
CAUTION:
Stresses beyond the ratings specified in
This is a stress only rating and operation of the device at these or any other conditions above those indicated in the
operational sections of this specification is not implied.
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4
Supply
BOOT & UGATE to GND --------------------------------------------------------------------------------------------- 19V
Input, Output or I/O Voltage ----------------------------------------------------------------------------------------- GND-0.3V to 7V
Power Dissipation, P
SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.625W
Package Thermal Resistance
SOP-8, θ
Ambient Temperature Range ---------------------------------------------------------------------------------------- 0°C to +70°C
Junction Temperature Range ---------------------------------------------------------------------------------------- 0°C to +125°C
Storage Temperature Range ----------------------------------------------------------------------------------------
Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C
Input
JA
-------------------------------------------------------------------------------------------------------------- 160° C/W
Voltage, V
D
@ T
CC
------------------------------------------------------------------------------------------- 7V
A
= 25°C
“
Absolute Maximum Ratings
UGATE (Pin 5)
Connect UGATE pin to the PWM converter's upper
MOSFET gate. This pin provides the gate drive for the
upper MOSFET.
BOOT (Pin 6)
This pin provides ground referenced bias voltage to the
upper MOSFET driver. A bootstrap circuit is used to create
a voltage suitable to drive a logic-level N-Channel
MOSFET when operating at a single 5V power supply.
This pin also could be powered from ATX 12V, in this
situation, a internal 6.5V regulator will supply to VCC pin
for internal voltage bias.
PGOOD (Pin 7)
PGOOD is an open collector output used to indicate the
status of the PWM converter output voltage. This pin is
pulled low when the FB is not over 90% of the reference
voltage.
SS (Pin 8)
Connect a capacitor from this pin to ground. This capacitor,
along with an internal 22μA current source, sets the soft-
start internal of the synchronous PWM converter.
”
may cause permanent damage to the device.
DS9209/A-08 March 2007
−
65°C to +150°C