RT9259AGS Richtek USA Inc, RT9259AGS Datasheet - Page 3

• Manufacturer Part Number: RT9259AGS
• Description: IC CTRLR PWM SYNC BUCK 14SOP
• Manufacturer: Richtek USA Inc

Specifications of RT9259AGS

• Topology: Step-Down (Buck) Synchronous (1), Linear (LDO) (1)
• Function: Any Function
• Number Of Outputs: 2
• Frequency - Switching: 300kHz
• Voltage/current - Output 1: Controller
• Voltage/current - Output 2: Controller
• W/led Driver: No
• W/supervisor: No
• W/sequencer: No
• Voltage - Supply: 10.8 V ~ 13.2 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 14-SOIC (0.154", 3.90mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Functional Pin Description
BOOT (Pin 1)
Bootstrap supply for the upper gate driver. Connect the
bootstrap capacitor between BOOT pin and the PHASE
pin. The bootstrap capacitor provides the charge to turn on
the upper MOSFET.
RT_DIS (Pin 2)
Connect a resistor from RT_DIS to GND to set frequency.
In addition, if this pin is pulled down towards GND, it will
disable both regulator outputs until released.
COMP (Pin 3)
Buck converter external compensation. This pin is used
to compensate the control loop of the buck converter.
FB (Pin 4)
Buck converter feedback voltage. This pin is the inverting
input of the PWM error amplifier. FB senses the switcher
output through an external resistor divider network.
DRV (Pin 5)
Connect this pin to the gate of an external MOSFET. This
pin provides the drive for the linear regulator’ s pass
MOSFET.
FBL (Pin 6)
Linear regulator feedback voltage. This pin is the inverting
input of the LDO error amplifier and protection monitor.
Connect this pin to an external resistor divider network of
the linear regulator.
GND (Pin 7)
Signal ground for the IC. All voltages levels are measured
with respect to this pin.
VCC12 (Pin 8)
Connect this pin to a well-decoupled 12V bias supply. It is
also the positive supply for the lower gate driver, LGATE.
DS9259A-02 March 2007
VREF (Pin 9)
0.8V reference voltage output.
OCSET (Pin 10)
Connecting a resistor (R
of the upper MOSFET and the drain of the lower MOSFET
sets the over-current trip point. R
current source, and the lower MOSFET on resistance,
R
according to the following Equation :
LGATE (Pin 11)
Lower gate driver output. Connect to the gate of the low-
side power N-Channel MOSFET. This pin is monitored by
the adaptive shoot-through protection circuitry to determine
when the lower MOSFET has turn off.
PGND (Pin 12)
Power ground return for the lower gate driver.
PHASE (Pin 13)
Connect this pin to the source of the upper MOSFET and
the drain of the lower MOSFET. This pin is monitored by
the adaptive shoot-through protection circuitry to determine
when the upper MOSFET has turned off.
UGATE (Pin 14)
Upper gate driver output. Connect to gate of the high-side
power N-Channel MOSFET. This pin is monitored by the
adaptive shoot-through protection circuitry to determine
when the upper MOSFET has turned off.
DS(ON)
, set the converter over-current trip point (I
I
OCSET
=
R
DS(ON)
40uA
OCSET
of
×
the
) from this pin to the source
R
OCSET
lower
OCSET
RT9259A
−
, an internal 40μA
MOSFET
0.4V
www.richtek.com
OCSET
3
)