3

DS8298-01

November 2011

www.richtek.com

RT8298

Copyright

2011 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

©

Functional Pin Description

Pin No.

WDFN-14L 4x3

SOP-8

(Exposed Pad)

Pin Name

Pin Function

1

6

FB

Feedback Input. This pin is connected to the converter output. It

is used to set the output of the converter to regulate to the

desired value via an external resistive divider. The feedback

reference voltage is 0.808V typically.

2

--

PGOOD

Power Good Indicator with Open Drain. (for RT8298ZQW only)

A 100k

Ω pull-high resistor is needed. The output of this pin is

pulled to low when the FB is lower than 0.75V; otherwise it is

high impedance.

3

7

EN/SYNC

Enable

or External Frequency

Synchronization

Input. A

logic-high (2V < EN < 5.5V) enables the converter; a logic-low

forces the IC into shutdown mode reducing the supply current to

less than 3

μA. For external frequency synchronization operation,

the available frequency range is from 300kHz to 1.5MHz.

4, 5, 6

8

VIN

Power Input. The available input voltage range is from 4.5V to

24V. A 22

μF or larger input capacitor is needed to reduce

voltage spikes at the input.

7

--

NC

No Internal Connection.

8, 9, 10

1

SW

Switching Node. Output of the internal high side MOSFET.

Connect this pin to external low-side N-MOSFET, inductor and

bootstrap capacitor.

11

2

BOOT

Bootstrap for High side Gate Driver. Connect a 1

μF ceramic

capacitor between the BOOT pin and SW pin.

12

3

VCC

BG Driver Bias Supply. Decouple with a 1

μF X5R/X7R ceramic

capacitor between the VCC pin and GND.

13

4

BG

Gate Driver Output. Connect this pin to the gate of the external

low-side N-MOSFET.

14,

15 (Exposed Pad)

5,

9 (Exposed Pad)

GND

Ground. The exposed pad must be soldered to a large PCB and

connected to GND for maximum thermal dissipation.