MC33565 Datasheet, PDF (1/8 Pages) ON Semiconductor – 200 mA INTELLIGENT LDO REGULATOR WITH SMART BYPASS CONTROL

Order this document by MC33565/D
Smart Voltage Regulator for
Peripheral Card Applications
The MC33565 Low Dropout Regulator is designed for computer
peripheral card applications complying with the instantly available
requirements as specified by ACPI objectives. The MC33565 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 5V power supply or the 3.3V aux supply.
The MC33565 provides a regulated output voltage of 3.3V via either an
internal low drop out 5.0V–to–3.3V 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 (5V main supply available) the 3.3V
output is provided from the internal low dropout regulator at an output current
of 200mA. When the motherboard enters sleep mode, the MC33565 operates
from the 3.3V 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 3.3V even during transitions to and from sleep mode.
MC33565 Features:
• Output Regulated to 2% Over Temperature
• Output current up to 200mA
• 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
• Evaluation Kit Available: (P.N. MC33565EVK)
+3.3 Vin
Simplified Block Diagram
MC33565
200 mA INTELLIGENT LDO
REGULATOR WITH SMART
BYPASS CONTROL
SEMICONDUCTOR
TECHNICAL DATA
8
1
1
+5 Vin
2
N/C
3
+3.3 Vin
4
Gnd
8
Drive out
7
+3.3 Vout
MC33565 ⁶
Sense in
5
N/C
D SUFFIX
PLASTIC PACKAGE
CASE 751–06
(SO–8)
Compensation
&
Hysteresis
Hyst sw
Comp
Driver _{Drive out}
Ref &
Detect _Vref
5V detect
External
P–channel
MOSFET
+3.3 Vout
Pins 2 and 5 Not Connected
ORDERING INFORMATION
Device
MC33565D
Type
3.3V
Package
SO–8
+5 Vin
LDO
+3.3 Vout
Sense in
MOTOROLA ANALOG IC DEVICE DATA
External
4.7 µF
cap
© Motorola, Inc. 1999
Rev 0, 6/99
1