XRP7665
3A 18V Synchronous Step-Down Converter
PIN DESCRIPTION
Name
Pin Number
Description
Bootstrap pin.
1
2
Connect a 0.01µF or greater bootstrap capacitor between the BS pin and the SW pin.
The voltage across the bootstrap capacitor drives the internal high-side power MOSFET.
BS
Power input pin.
A capacitor should be connected between the IN pin and GND pin to keep the input
voltage constant.
IN
Power switch output pin.
This pin is connected to the inductor and the bootstrap capacitor.
3
4
SW
Ground signal pin.
GND
Feedback pin.
An external resistor divider connected to FB programs the output voltage. If the
feedback pin exceeds 1.1V the over-voltage protection will trigger. If the feedback
voltage drops below 0.3V the oscillator frequency is lowered to achieve short-circuit
protection.
5
FB
Compensation pin.
This is the output of transconductance error amplifier and the input to the current
comparator. It is used to compensate the control loop. Connect an RC network form
this pin to GND.
6
7
COMP
EN
Control input pin.
Forcing this pin above 2.7V enables the IC. Forcing this pin below 0.75V shuts down the
I C .
P u l l
u p t o V I N wi t h 1 0 0 k Ω f o r
a u t o ma t i c
s
Soft-start control input pin.
Connect a capacitor from SS to GND to set the soft-start period. A 0.1µF capacitor sets
the soft start period to 15ms. To disable the soft-start feature, leave SS unconnected.
8
SS
-
Exposed Pad
Connect to GND through PCB.
EP
ORDERING INFORMATION
Temperature
Part Number
Packing
Quantity
Marking
Package
Note 1
Note 2
Range
XRP7665I
YYWWF
X
RoHS Compliant
Halogen Free
2.5K/Tape & Reel
XRP7665IDBTR-F
XRP7665EVB
SOIC-8(EP)
-4 0 ° C A≤≤T+8 5 ° C
XRP7665 Evaluation Board
“ Y Y ”
= –Y“ eWaWr”
=
Wo r k– “WXe”e k= L o t ; wNhuenmabpeplircable.
© 2013 Exar Corporation
4/12
Rev. 2.0.1
EXAR [ EXAR CORPORATION ]
