
1
Date: 5/25/04
SP6231 500mA, 3.3V Linear Regulator
Copyright 2004 Sipex Corporation
FEATURES
■
“Tiny” DFN Package Offers Excellent Thermal
Characteristics (also available in NSOIC)
■
“Glitch Free” Transition between Two Supplies
■
3.3V Fixed LDO Output Voltage
■
400
μ
A Quiescent Current @500mA Load
■
Fast Transient Response
■
Current Limit Protection
■
Thermal Shutdown Protection with Hysteresis
■
Auxiliary Supply Control
■
Internal 0.2
PFET Switch Eliminates External
FETs
■
Kelvin Connection with 3.3V Feedback
500mA, 3.3V Linear Regulator with Auxiliary Backup
SP6231
DESCRIPTION
APPLICATIONS
■
USB Peripherals
■
NIC Cards
■
PCMCIA/PCI Cards
■
Desktop Computers
■
Dual Power Systems
The SP6231 is a 500mA, 3.3V LDO with an integrated auxiliary voltage input switch. During
normal operation, the SP6231 acts as a standard LDO with an output voltage of 3.3V delivering
up to 500mA. When the 5V input drops below 4.4V, the 3.3V, V
AUX
input is switched to the output
through an internal PFET, maintaining a constant “glitch free” output voltage.
The SP6231 is ideally suited for NIC cards and portable battery powered equipment. When a
desktop computer reverts to sleep mode, its 5V bus is removed, leaving only the 3.3V bus. The
SP6231’s auxiliary output passes the 3.3V bus through, keeping the NIC card available for any
Wake-On-LAN command. In battery powered applications, the SP6231 draws power from any
available 5V USB connection and reverts to battery power when the USB power is removed.
V
OUT
3.3V
@ 500mA
SP6231
GND
OUT
+5V USB
V
IN
V
AUX
V
SENSE
+3.3V
AUX
C2
2.2
μ
F
GND
GND
C1
2.2
μ
F
C3
10
μ
F
TYPICAL APPLICATION CIRCUIT
Now Available in Lead Free Packaging
1
2
3
4
5
6
7
8
V
AUX
V
IN
SP6231
8 Pin NSOIC
GND
V
OUT
GND
GND
GND
V
S E N S E