XRP7674 Datasheet, PDF (4/12 Pages) Exar Corporation – 2A 18V Synchronous PFM/PWM Step-Down Regulator

PIN ASSIGNMENT
XRP7 6 7 4
2 A 1 8 V Sy n ch r on ou s PFM/ PW M St ep - Dow n Reg u lat or
Fig. 3: XRP7674 Pin Assignment (SOIC - 8)
PIN DESCRIPTION
Name
Pin Number
BS
1
IN
2
SW
3
GND
4
FB
5
COMP
6
EN
7
SS
8
Description
Bootstrap pin.
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.
Power input pin.
A capacitor should be connected between the IN pin and GND pin to keep the input
voltage constant.
Power switch output pin.
This pin is connected to the inductor and the bootstrap capacitor.
Ground pin.
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 o scillator frequency is lowered to achieve short - circuit
protection.
Compensation pin.
This is the output of transconductance e rror 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.
Control input pin.
Drive EN high/low in order to turn on/off the regulator
. When the IC is in shutdown
mode all functions are disabled to decrease the supply current below 1µA.
This input
FDQEHFRQQHFWHGWR9,1SLQWKURXJKDNƻUHVL
operations.
Soft - start control input pin.
Connect a capacitor from SS to GND to set th
e soft - start period. A 0.1µF capacitor sets
the soft start period to 1 5ms. To disable the soft - start feature, leave SS unconnected.
ORDERING INFORMATION
Part Number
XRP7674 IDTR -F
XRP7674 EVB
Temperature
Range
Marking
XRP7674 I
- ƒ&A””7ƒ& YYWWF
X
XRP7674 Evaluation Board
Package
SOIC -8
Packing
Quantity
Note 1
2.5 K/Tape & Reel ^{RoHS Compliant}
Halogen Free
³<<´ ±<³H:D:U´ :RUN±³:;H´HN/RW; w1heXnPapEplHicaUble.
Note 2
© 2013 Exar Corporation
4/ 12
Rev. 1.0.0