2

DS7259-00

January 2012

www.richtek.com

RT7259

©

Copyright

2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Ordering Information

Note :

Richtek products are :

RoHS compliant and compatible with the current require-

ments of IPC/JEDEC J-STD-020.

Suitable for use in SnPb or Pb-free soldering processes.

Marking Information

Pin Configurations

(TOP VIEW)

WDFN-14L 4x3

FB

PGOOD

VIN

VIN

GND

BG

VCC

SW

BOOT

EN/SYNC

VIN

SW

NC

SW

13

12

11

1

2

3

4

5

14

69

10

GND

15

78

14= : Product Code

YMDNN : Date Code

Functional Pin Description

Pin No.

Pin Name

Pin Function

1

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. 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

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

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

SW

Switching Node. Output of the internal high side MOSFET. Connect this pin to

external low side N-MOSFET, inductor and bootstrap capacitor.

11

BOOT

Bootstrap for High side Gate Driver. Connect a 1

μF ceramic capacitor between

the BOOT pin and SW pin.

12

VCC

BG Driver Bias Supply. Decouple with a 1

μF X5R/X7R ceramic capacitor

between the VCC pin and GND.

13

BG

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

N-MOSFET.

14,

15 (Exposed Pad)

GND

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

GND for maximum thermal dissipation.

RT7259

Package Type

QW : WDFN-14L 4x3 (W-Type)

Lead Plating System

G : Green (Halogen Free and Pb Free)

14=YM

DNN