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C5
L1 15uH
D1
B340A
10nF
U1
OUTPUT
3.3V/2A
2
7
8
4
INPUT
IN
R1
4.75V to 21V
3
SW
FB
OFF
ON
25.8KΩ 1%
EN
SS
C1
10uF/35V
C2
5
6
CERAMIC x2
(Optional)
C6
C4
R2
22uF/6.3V
CERAMIC x2
GND COMP
C3
R3
10KΩ 1%
0.1uF
RS6508‐ADS
5.6KΩ
8.2nF
Pin Assignments
MSOP‐10(EP)
SOP‐8
PACKAGE
PIN
SYMBOL
NC
DESCRIPTION
1
‐
No Connect.
Bootstrap. This capacitor (C5) is needed to drive the power switch’s gate
above the supply voltage. It is connected between the SW and BS pins to
form a floating supply across the power switch driver. The voltage across
C5 is about 5V and is supplied by the internal +5V supply when the SW pin
voltage is low.
2
1
BS
3
4
‐
NC
IN
No Connect.
Supply Voltage. The RS6515 operates from a 4.75V to 20V unregulated
input. C1 is needed to prevent large voltage spikes from appearing at the
input.
2
MSOP‐10(EP)
Power Switching Output. SW is the switching node that supplies power to
the output. Connect the output LC filter from SW to the output load. Note
that a capacitor is required from SW to BS to power the high‐side switch.
Ground.
Feedback Input. FB senses the output voltage and regulates it. Drive FB
with a resistive voltage divider from the output voltage to ground. The
feedback threshold is 0.92V. See Setting the Output Voltage.
Compensation Node. COMP is used to compensate the regulation control
loop. Connect a series RC network from COMP to GND. In some cases, an
additional capacitor from COMP to GND is required. See Compensation.
Enable Input. EN is a digital input that turns the regulator on or off. Drive
EN high to turn on the regulator, drive it low to turn it off. For automatic
startup, leave EN unconnected.
5
3
4
5
SW
GND
FB
/
6,11
SOP‐8
7
8
6
COMP
9
7
8
EN
SS
Soft‐Start. Connect SS to an external capacitor to program the soft‐start. If
unused, leave it open.
10
DS‐RS6515‐08 JULY, 2010
www.Orister.com
ORISTER [ ORISTER CORPORATION ]
