SC4521 View Datasheet(PDF) - Semtech Corporation
Part Name
Description
MFG CO.
'SC4521' PDF : 18 Pages View PDF
POWER MANAGEMENT
Pin Configurations
TOP VIEW
BST
1
IN
2
SW
3
GND
4
8
SS
7
COMP
6
FB
5
EN
(SOIC-8L-EDP)
SC4521
Ordering Information
Part Number (1)(2)
Package
SC4521SETRT
SOIC-8L-EDP
SC4521EVB
EVALUATION BOARD
Notes:
(1) Only available in tape and reel packaging. A reel
contains 2500 devices.
(2) Lead free product. This product is WEEE and
RoHS compliant.
Pin Descriptions
Pin # Pin Name Pin Function
1
BST This pin provides power to the internal NPN switch. The minimum turn on voltage for this switch
is 2.7V.
2
IN
Pin IN delivers all power required by control and power circuitry. This pin sees high di/dt during
switching. A decoupling capacitor should be attached to this pin as close as possible.
3
SW Pin SW is the emitter of the internal switch. The external freewheeling diode should be connected
as close as possible to this pin.
4
GND All voltages are measured with respect to this pin. The decoupling capacitor and the freewheeling
diode should be connected to GND as short as possible.
5
EN
This is the chip enable input. The regulator is switched on if EN is high, and it is off if EN is low.
The regulator is in standby mode when EN is low, and the input supply current is reduced to a few
microamperes.
6
FB
Feedback input for adjustable output controllers.
7
COMP This is the output of the internal error amplifier and input of the peak current comparator. A
compensation network is connected to this pin to achieve the specified performance.
8
SS
Soft start pin. An external capacitor connected from this pin to GND sets the soft start time.
-
THERMAL Pad for heatsinking purposes. Connect to ground plane using multiple vias. Not connected
PAD internally.
2007 Semtech Corp.
4
www.semtech.com
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