MIC2779 Micrel Semiconductor, MIC2779 Datasheet

no-image

MIC2779

Manufacturer Part Number
MIC2779
Description
Voltage Monitor with Adjustable Hysteresis Preliminary Information
Manufacturer
Micrel Semiconductor
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
MIC2779H-1YM5
Manufacturer:
Micrel Inc
Quantity:
1 805
Part Number:
MIC2779H-1YM5
Manufacturer:
MICREL/麦瑞
Quantity:
20 000
Part Number:
MIC2779H-2BM5
Manufacturer:
MICREL
Quantity:
96
Part Number:
MIC2779H-2YM5
Manufacturer:
MICREL
Quantity:
10 200
Company:
Part Number:
MIC2779H-2YM5
Quantity:
1 604
Part Number:
MIC2779L-1BM5
Manufacturer:
MICREL
Quantity:
18 365
Part Number:
MIC2779L-1BM5 TR
Manufacturer:
NS
Quantity:
6 504
Part Number:
MIC2779L-2YM5
Manufacturer:
MICREL/麦瑞
Quantity:
20 000
General Description
The MIC2779 is a voltage monitor—uniquely designed to
detect two separate voltage thresholds—combined with a
delay generator and logic. It is designed for monitoring the
battery supply of portable digital systems, particularly PDAs,
pagers, and cellular telephones.
High- and low-voltage thresholds can be adjusted indepen-
dently, allowing for wide hysteresis. Voltage detection thresh-
olds are accurate to 2%.
If the battery voltage falls below the low-voltage threshold, the
output /RST or RST is asserted and latched, preventing
system operation until the battery is replaced or recharged.
Internal logic prevents the output from chattering due to
battery recovery or load removal. The output is asserted for
140ms (minimum) when a fresh battery is inserted. For
applications requiring open-drain output, see MIC2778/
MIC833.
The IC’s power supply input is separate from the detector
inputs, allowing the MIC2779 to be powered from a down-
stream supply, such a boost converter. Supply current is
extremely low (1 A, typical), making it ideal for portable
applications.
A high-precision 1% grade is available. The MIC2779 is
supplied in Micrel’s IttyBitty™ 5-lead SOT-23-5 package.
Typical Application
IttyBitty™ is a trademark of Micrel, Inc.
June 2000
MIC2779
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
Li-Ion
Cell
604k
1%
56k
1%
340k
1%
Cellular Telephone Battery Monitor
V
V
VDD
LTH
HTH
BAT(hi)
BAT(lo)
MIC2779L
= 3.6V
= 3.1V
/RST
GND
1
Features
• Optimized for PDAs, cellular telephones, pagers,
• Independently adjustable high- and
• Internal logic prevents battery-voltage-fluctuation chatter
• High 2% voltage threshold accuracy; 1% available
• Built in 140ms (minimum) delay deglitches output
• Extremely low 1 A typical supply current
• For applications requiring open-drain output, see
• Immune to brief power supply transients
• 5-lead SOT-23 package
Applications
• PDAs
• Pagers
• Cordless phones
• Consumer electronics
• Embedded controllers
• Personal electronics
Voltage Monitor with Adjustable Hysteresis
and other battery-powered devices
low-voltage thresholds
MIC2778/MIC833
MIC5207-3.0BM5
IN
EN
GND
OUT
BYP
Preliminary Information
470pF
MIC2779
V
3.0V
4.7µF
OUT
MIC2779
Micrel

Related parts for MIC2779

MIC2779 Summary of contents

Page 1

... For applications requiring open-drain output, see MIC2778/ MIC833. The IC’s power supply input is separate from the detector inputs, allowing the MIC2779 to be powered from a down- stream supply, such a boost converter. Supply current is extremely low (1 A, typical), making it ideal for portable applications. ...

Page 2

... UPB2 MIC2779L-1BM5 UPB1 Pin Configuration LTH GND HTH RST VDD SOT-23-5 (M5) “H” Version Pin Description Pin Number Pin Number Pin Name MIC2779H MIC2779L MIC2779 Output Polarity Accuracy Active-High RST 2% Active-High RST 1% Active-Low /RST ...

Page 3

... V HTH V LTH RST Propagation delays not shown for clarity. Note A. The MIC2779 ignores very brief transients. See “Applications Information” for details. 3 (Note 2) ) .................................. +1.5V to +5. –0.3V to +6.0V LTH HTH /RST RST ) ............. – + Min Typ ...

Page 4

... Upon being replaced, or being recharged above a second higher pro- grammed trip point, the output remains low (MIC2779L) or high (MIC2779H) for a minimum of 140ms and then sends a reset signal to a microprocessor or other downstream com- ponent. See “Timing Diagram.” ...

Page 5

... As shown in Figure 2, the narrower the transient, the deeper the threshold overdrive that will be ignored by the MIC2779. The graph represents the typical allowable transient duration for a given amount of threshold overdrive that will not gener- ate a reset ...

Page 6

... MIC2779 Package Information 1.90 (0.075) REF 0.95 (0.037) REF 3.02 (0.119) 2.80 (0.110) 0.50 (0.020) 0.35 (0.014) MIC2779 1.75 (0.069) 3.00 (0.118) 1.50 (0.059) 2.60 (0.102) DIMENSIONS: MM (INCH) 1.30 (0.051) 0.90 (0.035 0.15 (0.006) 0.60 (0.024) 0.00 (0.000) 0.10 (0.004) SOT-23-5 (M5) 6 Micrel 0.20 (0.008) 0.09 (0.004) June 2000 ...

Page 7

... MIC2779 June 2000 7 Micrel MIC2779 ...

Page 8

... This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc. MIC2779 + 1 (408) 944-0970 http://www ...

Related keywords