LM3881MMX/NOPB National Semiconductor, LM3881MMX/NOPB Datasheet

IC POWER SUPPLY SEQUENCER 8MSOP

LM3881MMX/NOPB

Manufacturer Part Number
LM3881MMX/NOPB
Description
IC POWER SUPPLY SEQUENCER 8MSOP
Manufacturer
National Semiconductor
Datasheet

Specifications of LM3881MMX/NOPB

Applications
Power Supply Sequencer
Voltage - Input
2.7 ~ 5.5 V
Current - Supply
80µA
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
For Use With
LM3881EVAL - BOARD EVALUATION FOR LM3881
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Supply
-
Other names
LM3881MMX

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LM3881MMX/NOPB
Manufacturer:
NS/国半
Quantity:
20 000
Part Number:
LM3881MMX/NOPB
0
Company:
Part Number:
LM3881MMX/NOPB
Quantity:
9 000
© 2008 National Semiconductor Corporation
LM3881
Power Sequencer
General Description
The LM3881 Power Sequencer offers the easiest method to
control power up and power down of multiple power supplies
(switching or linear regulators). By staggering the startup se-
quence, it is possible to avoid latch conditions or large in-rush
currents that can affect the reliability of the system.
Available in MSOP-8 package, the Power Sequencer con-
tains a precision enable pin and three open drain output flags.
Upon enabling the LM3881, the three output flags will se-
quentially release, after individual time delays, permitting the
connected power supplies to startup. The output flags will fol-
low a reverse sequence during power down to avoid latch
conditions. Time delays are defined using an external capac-
itor and the output flag states can be inverted by the user.
Typical Application Circuit
300484
Features
Applications
Easiest method to sequence rails
Power up and power down control
Input voltage range of 2.7V to 5.5V
Small footprint MSOP-8 package
Low quiescent current of 80 µA
Output invert feature
Timing controlled by small value external capacitor
Multiple Supply Sequencing
Microprocessor / Microcontroller Sequencing
FPGA Sequencing
30048401
www.national.com
April 8, 2008

Related parts for LM3881MMX/NOPB

LM3881MMX/NOPB Summary of contents

Page 1

... Time delays are defined using an external capac- itor and the output flag states can be inverted by the user. Typical Application Circuit © 2008 National Semiconductor Corporation Features ■ Easiest method to sequence rails ■ ...

Page 2

Connection Diagram Ordering Information Order Number LM3881MM LM3881MMX LM3881MME Pin Descriptions Pin # www.national.com Top View MSOP-8 Package Package Type NSC Package Drawing MSOP-8 MUA08A Name VCC EN GND INV TADJ FLAG3 ...

Page 3

... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VCC, EN, INV, TADJ, FLAG1, FLAG2, FLAG3 to GND Storage Temperature Range Junction Temperature Lead Temperature (Soldering, 5 sec.) Minimum ESD Rating (Note 2) Electrical Characteristics apply over the full Operating Temperature Range (T test, design or statistical correlation ...

Page 4

Typical Performance Characteristics Quiescent Current vs V Enable Threshold vs Temperature Time Delay vs Temperature ( Nominal) ADJ www.national.com V = 3.3V unless otherwise specified. CC Quiescent Current vs Temperature CC 30048414 30048416 30048418 4 30048415 Time ...

Page 5

FLAG Voltage vs Current 30048420 5 www.national.com ...

Page 6

Block Diagram www.national.com 6 30048403 ...

Page 7

Application Information OVERVIEW The LM3881 Power Sequencer provides a simple solution for sequencing multiple rails in a controlled manner. A clock sig- nal is established that facilitates control of the power up and power down of three open drain FET ...

Page 8

FIGURE 2. Power Up Sequence, INV Low FIGURE 3. Power Up Sequence, INV High 8 30048425 30048405 ...

Page 9

FIGURE 4. Power Down Sequence, INV Low FIGURE 5. Power Down Sequence, INV High 9 30048406 30048424 www.national.com ...

Page 10

ENABLE CIRCUIT The enable circuit is designed with an internal comparator, referenced to a bandgap voltage (1.22V), to provide a preci- sion threshold. This allows the timing to be set externally using a capacitor as shown in the diagram below. ...

Page 11

FIGURE 10. Incomplete Sequence Timing, INV Low 11 30048412 30048413 www.national.com ...

Page 12

Physical Dimensions www.national.com inches (millimeters) unless otherwise noted MSOP-8 Package NS Package Number MUA08A 12 ...

Page 13

Notes 13 www.national.com ...

Page 14

... For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock Conditioners www.national.com/timing Data Converters www.national.com/adc Displays www.national.com/displays Ethernet www.national.com/ethernet Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www ...

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