RT6258B/C
Functional Pin Description
pin No.
Pin Name
Pin Function
Boot-strap pin. Supply high-side gate driver. A 0.1F ceramic capacitor and
at least 10 RBOOT are connected between this pin and LX pin.
1
BOOT
2,3
4
LX
Inductor pin. Connect this pin to the switching node of inductor.
Power ground.
PGND
VIN
5
Input pin. Decouple this pin to GND pin with at least 10F ceramic cap.
Enable control. Pull this pin high to turn on the Buck. Do not leave this pin
floating. EN pin will also be used to set USM mode, when EN pin voltage is
between 0.8V and 1.7V, it will enter USM mode, if EN pin voltage is between
2.3V and 23V, then it is normal mode.
EN
(RT6258B)
6
Enable control. Pull this pin high to turn on the Buck. Do not leave this pin
floating. EN pin will also be used to set USM mode, when EN pin voltage is
between 0.8V and 1.7V, it will enter USM mode, if EN pin voltage is between
2.3V and 23V, then it is normal mode.
EN
(RT6258C)
Power good indicator. Open drain output when the output voltage is higher
than 90% of regulation point.
7
8
PGOOD
AGND
Analog ground.
VCC
5V linear regulator output for internal control circuit. A capacitor (typical 1F)
(RT6258B)
should be connected to AGND. Don’t connect to external Load.
9
FF
(RT6258C)
Output feedforward pin. Connect RC network from the output to this pin.
VOUT
(RT6258B)
Output pin. Connect to the output of DC-DC regulator. The pin also provides
the bypass input for 3.3V LDO.
10
11
12
VOUT
(RT6258C)
Output pin. Connect to the output of DC-DC regulator. The pin also provide
the bypass input for 5V LDO.
LDO3
(RT6258B)
Internal 3.3V LDO output. Bypass a capacitor to GND. This pin is also
capable sourcing 100mA current for external load.
VCC
(RT6258C)
5V linear regulator output for internal control circuit. A capacitor (typical 1F)
should be connected to AGND. Don’t connect to external load.
FF
(RT6258B)
Output feedforward pin. Connect RC network from the output to this pin.
LDO5
(RT6258C)
Internal 5V LDO output. Bypass a capacitor to GND. This pin is also capable
sourcing 100mA current for external load.
Copyright 2019 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS6258B/C-02 October 2019
www.richtek.com
3
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
