MC33566 Datasheet, PDF (1/6 Pages) ON Semiconductor – Smart Voltage Regulator for Peripheral Card Applications

MC33566
Smart Voltage Regulator for
Peripheral Card Applications
The MC33566 Low Dropout Regulator is designed for computer
peripheral card applications complying with the instantly available
requirements as specified by ACPI objectives. The MC33566 permits
glitch−free transitions from “sleep” to “active” system modes and has
internal logic circuitry to detect whether the system is being powered
from the motherboard main 5.0 V power supply or the 3.3 V aux supply.
The MC33566 provides a regulated output voltage of 3.3 V via
either an internal low dropout 5.0 V−to−3.3 V voltage regulator or an
external P−channel MOSFET, depending on the operating status of the
system in which the card is installed. During normal operating mode
(5.0 V main supply available) the 3.3 V output is provided from the
internal low dropout regulator at an output current of 0.4 A. When the
motherboard enters sleep mode, the MC33566 operates from the 3.3 V
aux supply and routes the aux current to the output via the external
P−channel MOSFET bypass transistor controlled by the drive out pin.
As a result, the output voltage provided to the peripheral card remains
constant at 3.3 V even during host systems transitions to and from
sleep mode.
MC33566 Features:
• Output Current up to 0.4 A
• Excellent Line and Load Regulation
• Low Dropout Voltage
• Prevents Reverse Current Flow During Sleep Mode
• Glitch−Free Transfer from Sleep Mode to Active Mode
• Compatible with Instantly Available PC Systems
+3.3 V_aux
Compensation
&
Hysteresis
Hyst sw
Comp
Driver _{Drive out}
External
P−channel
MOSFET
Ref &
Detect _Vref
5V detect
+3.3 V_out
http://onsemi.com
MARKING
DIAGRAM
1
5
D²PAK
D2T SUFFIX
CASE 936A
Pin
1. Vaux
2. V_in
3. Gnd
4. V_out
5. Drv
M5
661
AWLYWW
1
5
Note: Tab is ground
A = Assembly Location
WL = Wafer Lot
Y = Year
WW = Work Week
ORDERING INFORMATION
Device
Package
Shipping^†
MC33566D2T−1
D²PAK
50 Units/Rail
MC33566D2T−1RK D²PAK 800 Tape & Reel
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
+5 V_in
+3.3 V_out
LDO
Figure 1. Simplified Block Diagram
External
4.7 μF
cap
© Semiconductor Components Industries, LLC, 2006
1
September, 2006 − Rev. 3
Publication Order Number:
MC33566/D