RT8004
Functional Pin Description
Pin No.
RT8004PS RT8004PCP RT8004PQP
1
2
1
2
15
16
Pin
Name
VDD
Pin Function
Signal Input Supply. Decouple this pin to GND with a capacitor.
Normally VDD is equal to PVDD.
Power Good Indicator. Open-drain logic output that is pulled to
PGOOD ground when the output voltage is not within ±12.5% of regulation
point.
Error Amplifier Compensation Pin. The current comparator
COMP
threshold increases with this control voltage. Connect external
compensation elements to this pin to stabilize the control loop.
FB
RT
SYNC
Feedback Pin. Receives the feedback voltage from a resistive
divider connected across the output.
Oscillator Resistor Input. Connecting a resistor to ground from this
pin sets the switching frequency.
External Clock Synchronization Input. The internal oscillator can
be synchronized to an external clock applied to this pin. If not use,
please connect this pin to VDD or GND.
Enable Control and Soft-Start Input. Forcing this pin below 0.5V
shuts down the RT8004. In shutdown all functions are disabled
drawing < 1uA of supply current. A capacitor to ground from this
pin sets the ramp time to full output current.
Signal Ground. All small-signal components, compensation
components and the exposed pad on the bottom side of the IC
should connect to this ground, which in turn connects to PGND at
one point.
Power Input Supply. Decouple this pin to PGND with a capacitor.
Internal Power MOSFET Switches Output. Connect this pin to the
inductor.
Power Ground. Connect this pin close to the terminal of C
IN
and
C
OUT
.
3
4
5
6
3
4
5
6
1
2
3
4
7
7
5
EN/SS
8
9, 16
10,11,
14, 15
12, 13
8, Exposed
Pad (17)
9, 16
10,11,
14, 15
12, 13
6, Exposed
GND
Pad (17)
7, 14
PVDD
8, 9, 12, 13 LX
10, 11
PGND
DS8004-03
September 2007
www.richtek.com
3
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
