RT9214GSP RICHTEK [Richtek Technology Corporation], RT9214GSP Datasheet - Page 2

• Manufacturer Part Number: RT9214GSP
• Description: 5V/12V Synchronous Buck PWM DC-DC Controller
• Manufacturer: RICHTEK [Richtek Technology Corporation]

RT9214
Typical Application Circuit
2
www.richtek.com
Functional Pin Description
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.
UGATE (Pin 2)
Upper gate driver output. Connect to the gate of 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.
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.
LGATE (Pin 4)
Lower gate drive output. Connect to the gate of low-side
power N-Channel MOSFET. This pin is monitored by the
adaptive shoot-through protection circuitry to determine
when the lower MOSFET has turned off.
VCC (Pin 5)
Connect this pin to a well-decoupled 5V or 12V bias
supply. It is also the positive supply for the lower gate
driver, LGATE.
R2
32
10
R1
C1
1uF
D1
200-1k
R4
1
5
6
3
R3
68
FB
BOOT
VCC
GND
0.1-0.33uF
C5
RT9214
Disable >
2.2
UGATE
PHASE
LGATE
OPS
2
8
7
4
Q3
3904
C2
0.1uF
R
2.2
OCSET
FB (Pin 6)
Switcher feedback voltage. This pin is the inverting input
of the error amplifier. FB senses the switcher output
through an external resistor divider network.
OPS (OCSET, POR and Shut-Down) (Pin 7)
This pin provides multi-function of the over-current setting,
UGATE turn-on POR sensing, and shut-down features.
Connecting a resistor (ROCSET) between OPS and
PHASE 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.
PHASE (Pin 8)
Connect this pin to the source of the upper MOSFET and
the drain of the lower MOSFET.
NC [Exposed Pad (9)]
No Internal Connection.
ML
Q1
MU
Q2
R
C
1uF
C3
L1
1000uFx3
C6 to C8
470uF
C4
V
V
OUT
REF
DS9214-13
:
=
(0.8V
Internal
V
IN
REF
in
±
power on stage and
×
2%)
reference
(1
September 2007
+
R3
R2
)
voltage