SP6231 Datasheet, PDF (1/10 Pages) Sipex Corporation – 500mA, 3.3V Linear Regulator with Auxiliary Backup

®
SP6231
500mA, 3.3V Linear Regulator with Auxiliary Backup
FEATURES
■ “Tiny” DFN Package Offers Excellent Thermal
Characteristics (also available in NSOIC)
■ “Glitch Free” Transition between Two Supplies
■ 3.3V Fixed LDO Output Voltage
■ 400µA Quiescent Current @500mA Load
■ Fast Transient Response
■ Current Limit Protection
V_{S E N S E} 1
V_IN 2
V_{OUT 3}
V_AUX 4
SP6231
8 Pin NSOIC
8 GND
7 GND
6 GND
5 GND
Now Available in Lead Free Packaging
■ Thermal Shutdown Protection with Hysteresis
■ Auxiliary Supply Control
■ Internal 0.2Ω PFET Switch Eliminates External
FETs
■ Kelvin Connection with 3.3V Feedback
APPLICATIONS
■ USB Peripherals
■ NIC Cards
■ PCMCIA/PCI Cards
■ Desktop Computers
■ Dual Power Systems
DESCRIPTION
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.
TYPICAL APPLICATION CIRCUIT
Date: 5/25/04
+5V USB
+3.3V_AUX
C1
2.2µF
C2
2.2µF
GND
V_IN
SP6231
V_SENSE
V_AUX
OUT
GND
C3
10µF
GND
V_OUT 3.3V
@ 500mA
SP6231 500mA, 3.3V Linear Regulator
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© Copyright 2004 Sipex Corporation