RT8290
Marking Information
RT8290GSP : Product Number
RT8290ZSP : Product Number
RT8290
GSPYMDNN
YMDNN : Date Code
RT8290
ZSPYMDNN
YMDNN : Date Code
Table 1. Recommended Component Selection
V
OUT
(V)
15
10
8
5
3.3
2.5
1.8
1.2
R1 (kΩ)
153
97.6
76.8
45.3
26.1
16.9
9.53
3
R2 (kΩ)
10
10
10
10
10
10
10
10
R
C
(kΩ)
30
20
15
13
6.8
6.2
4.3
3
C
C
(nF)
3.9
3.9
3.9
3.9
3.9
3.9
3.9
3.9
L (μH)
33
22
22
15
10
6.8
4.7
3.6
C
OUT
(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.
1
2
3
4,
9 (Exposed Pad)
5
6
Pin Name
BOOT
VIN
SW
GND
FB
COMP
Pin Function
Bootstrap for High Side Gate Driver. Connect a 10nF or greater ceramic capacitor
from the BOOT pin to SW pin.
Voltage Supply Input. The input voltage range is from 4.5V to 23V. A suitable large
capacitor must be bypassed with this pin.
Switching Node. Connect the output LC filter between the SW pin and output load.
Ground. The exposed pad must be soldered to a large PCB and connected to
GND for maximum power dissipation.
Output Voltage Feedback Input. The feedback reference voltage is 0.925V
typically.
Compensation Node. This pin is used for compensating the regulation control
loop. A series RC network is required to be connected from COMP to GND. If
needed, an additional capacitor can be connected from COMP to GND.
Enable Input. A logic high enables the converter, a logic low forces the converter
into shutdown mode reducing the supply current to less than 3μA. For automatic
startup, connect this pin to VIN with a 100kΩ pull up resistor.
Soft-Start Control Input. The soft-start period can be set by connecting a capacitor
from SS to GND. A 0.1μF capacitor sets the soft-start period to 15.5ms typically.
7
EN
8
SS
www.richtek.com
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DS8290-02 March 2011
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
