RT9218GS Richtek USA Inc, RT9218GS Datasheet - Page 3

• Manufacturer Part Number: RT9218GS
• Description: IC CTRLR PWM SYNC BUCK 14SOP
• Manufacturer: Richtek USA Inc

Specifications of RT9218GS

• 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: 5V, 12V
• 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

DS9218-08 March 2007
Functional Pin Description
UGATE (Pin 2)
Upper gate driver output. Connect to gate of the high-
side power N-MOSFET. This pin is monitored by the
adaptive shoot-through protection circuitry to determine
when the upper MOSFET has turned off.
BOOT (Pin 1)
Bootstrap supply pin 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.
PHASE (Pin 14)
Connect this pin to the source of the upper MOSFET and
the drain of the lower MOSFET.
OPS (OCSET, POR and Shut-Down) (Pin 13)
This pin provides multi-function of the over-current setting,
UGATE turn-on POR sensing, and shut-down features.
Connecting a resistor (R
pins sets the over-current trip point.
Pulling the pin to ground resets the device and all external
MOSFETs are turned off allowing the output voltage power
rails to float.
This pin is also used to detect V
issues an internal POR signal.
LGATE (Pin 4)
Lower gate drive output. Connect to gate of the low-side
power N-MOSFET. This pin is monitored by the adaptive
shoot-through protection circuitry to determine when the
lower MOSFET has turned off.
FB (Pin 12)
Switcher feedback voltage. This pin is the inverting input
of the error amplifier. FB senses the switcher output
through an external resistor divider network.
OCSET
) between OPS and PHASE
IN
in power on stage and
VCC (Pin 11)
Connect this pin to a well-decoupled 5V or 12V bias
supply. It is also the positive supply for the lower gate
driver, LGATE.
GND (Pin 3)
Both signal and power ground for the IC. All voltage levels
are measured with respect to this pin. Ties the pin directly
to the low-side MOSFET source and ground plane with
the lowest impedance.
DRV (Pin 5)
Connect this pin to the base/gate of an external transistor/
MOSFET. This pin provides the drive for the linear
regulator's pass transistor/MOSFET.
FBL (Pin 9)
Linear regulator feedback voltage. This pin is the inverting
input of the error amplifier and protection monitor. Connect
this pin to the external resistor divider network of the linear
regulator.
PGOOD (Pin 10)
PGOOD is an open-drain output used to indicate that the
regulator is within normal operating voltage ranges and
it's implemented with a specific sequence as following
chart.
NC (Pin 6,7,8)
No internal connection.
RT9218
www.richtek.com
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