RT8269GSP Ver la hoja de datos (PDF) - Richtek Technology
Número de pieza
componentes Descripción
Fabricante
RT8269GSP Datasheet PDF : 12 Pages
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RT8269
Table 1. Recommended Component Selection
VOUT (V)
R1 (kΩ) R2 (kΩ) RC (kΩ)
15
153
10
62
10
100
10
54
8
77
10
40
5
43
10
27
3.3
25.8
10
22
2.5
17
10
16
1.8
9.1
10
13
1.2
3
10
13
CC (nF)
0.82
1.2
1.5
2.2
2.7
2.2
2.2
2.2
L (μH)
22
22
15
15
10
6.8
4.7
2.2
COUT (μF)
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
Functional Pin Description
Pin No.
Pin Name
Pin Function
High Side Gate Drive Boost Input. BOOT supplies the drive for the high side
1
BOOT N-MOSFET switch. Connect a 10nF or greater capacitor from SW to BOOT to
power the high side switch.
Power Input. VIN supplies the power to the IC, as well as the step-down converter
2
VIN
switches. Bypass VIN to GND with a suitable large capacitor to eliminate noise on
the input to the IC.
Power Switching Output. SW is the switching node that supplies power to the
3
SW
output. Connect the output LC filter from SW to the output load. Note that a
capacitor is required from SW to BOOT to power the high side switch.
4,
9 (Exposed Pad)
GND
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
5
FB
Feedback Input. FB senses the output voltage to regulate said voltage. The
feedback reference voltage is 0.92V typically.
Compensation Node. COMP is used to compensate the regulation control loop.
6
COMP
Connect a series RC network from COMP to GND to compensate the regulation
control loop. In some cases, an additional capacitor from COMP to GND is
required.
Enable Input. EN is a digital input that turns the regulator on or off. Drive EN
7
EN
higher than 1.4V to turn on the regulator, lower than 0.4V to turn it off. If the EN pin
is open, it will be pulled to high by internal circuit.
Soft-Start Control Input. SS controls the soft start period. Connect a capacitor
8
SS
from SS to GND to set the soft-start period. A 0.1μF capacitor sets the soft-start
period to 10ms.
www.richtek.com
2
DS8269-02 March 2011
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