RT7258
Functional Pin Description
Pin No.
WDFN-14L 4x3
SOP-8
(Exposed Pad)
6
Pin Name
Pin Function
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.
Power Good Indicator with Open Drain. (for RT7258GQW only)
A 100kΩ 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.
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 3μA. For external frequency synchronization operation,
the available frequency range is from 300kHz to 1.5MHz.
Power Input. The available input voltage range is from 4.5V to
24V. A 22μF or larger input capacitor is needed to reduce
voltage spikes at the input.
No Internal Connection.
Switching Node. Output of the internal high side MOSFET.
Connect this pin to external low side N-MOSFET, inductor and
bootstrap capacitor.
Bootstrap for High side Gate Driver. Connect a 1μF ceramic
capacitor between the BOOT pin and SW pin.
BG Driver Bias Supply. Decouple with a 1μF X5R/X7R ceramic
capacitor between the VCC pin and GND.
Gate Driver Output. Connect this pin to the gate of the external
low side N-MOSFET.
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum thermal dissipation.
1
FB
2
--
PGOOD
3
7
EN/SYNC
4, 5, 6
7
8, 9, 10
11
12
13
8
--
1
2
3
4
VIN
NC
SW
BOOT
VCC
BG
14,
5,
GND
15 (Exposed Pad) 9 (Exposed Pad)
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
DS7258-00 January 2012
www.richtek.com
3
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