rt9212 Richtek Technology Corporation, rt9212 Datasheet - Page 3

• Manufacturer Part Number: rt9212
• Description: Dual Synchronous Buck Dc-dc Linear Power Controller
• Manufacturer: Richtek Technology Corporation

Functional Pin Description
UGATE1 (Pin 1)
Channel 1 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.
BOOT1 (Pin 2)
Bootstrap supply pin for the upper gate driver. Connect
the bootstrap capacitor between BOOT1 pin and the
PHASE1 pin. The bootstrap capacitor provides the charge
to turn on the upper MOSFET.
PHASE1 (Pin 3)
Connect this pin to the source of the upper MOSFET and
the drain of the lower MOSFET. PHASE1 is used to
monitor the Voltage drop across the upper MOSFET of
the channel 1 regulator for over-current protection.
NC (Pin 4, 7, 8)
No connection. Don’ t connect any component to this pin.
FB1 (Pin 5)
Channel 1 feedback voltage. This pin is the inverting input
of the error amplifier. FB1 senses the channel 1 through
an external resistor divider network.
COMP1 (Pin 6)
Channel 1 external compensation. This pin internally
connects to the output of the error amplifier and input of
the PWM comparator. Use a RC + C network at this pin
to compensate the feedback loop to provide optimum
transient response.
GNDA (Pin 9)
Signal ground for the IC. All voltage levels are measured
with respect to this pin. Ties the pin directly to ground
plane with the lowest impedance.
PHASE2 (Pin 10)
Connect this pin to the source of the upper MOSFET and
the drain of the lower MOSFET. PHASE2 is used to
monitor the Voltage drop across the upper MOSFET of
the channel 2 regulator for over-current protection.
DS9212-05 March 2007
Preliminary
BOOT2 (Pin 11)
Bootstrap supply pin for the upper gate driver. Connect the
bootstrap capacitor between BOOT2 pin and the PHASE2
pin. The bootstrap capacitor provides the charge to turn on
the upper MOSFET.
UGATE2 (Pin 12)
Channel 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.
PGND2 (Pin 13)
Return pin for high currents flowing in low-side power
N-MOSFET. Ties the pin directly to the low-side MOSFET
source and ground plane with the lowest impedance.
LGATE2 (Pin 14)
Channel 2 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.
VCC (Pin 15)
Connect this pin to a well-decoupled 5V bias supply. It is
also the positive supply for the lower gate driver, LGATE2.
DRV (Pin 16)
Connect this pin to the base of an external transistor. This
pin provides the drive for the linear regulator's pass
transistor.
FBL (Pin 17)
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.
FB2 (Pin 18)
Channel 2 feedback voltage. This pin is the inverting input
of the error amplifier. FB2 senses the channel 2 through an
external resistor divider network.
RT9212
www.richtek.com
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