MIC2778-2BM5 MICREL [Micrel Semiconductor], MIC2778-2BM5 Datasheet

no-image

MIC2778-2BM5

Manufacturer Part Number
MIC2778-2BM5
Description
Voltage Monitor with Adjustable Hysteresis
Manufacturer
MICREL [Micrel Semiconductor]
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
MIC2778-2BM5
Manufacturer:
MICREL
Quantity:
69
General Description
The MIC2778 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 inde-
pendently, allowing for wide hysteresis. Voltage detection
thresholds are accurate to 2%.
If the battery voltage falls below the low-voltage threshold,
the output (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
not requiring built-in delay, see MIC841.
The IC’s power supply input is separate from the detector
inputs, allowing the MIC2778 to be powered from a down-
stream supply, such a boost converter. Supply current is
extremely low (1µA, typical), making it ideal for portable
applications.
A high-precision 1% grade is available. The MIC2778 is sup-
plied in Micrel’s IttyBitty™ 5-lead SOT-23-5 package.
Ordering Information
* Underscore indicates a Pb-Free part.
Typical Application
IttyBitty™ is a trademark of Micrel, Inc.
January 2005
MIC2778
Standard
MIC2778-2BM5
MIC2778-1BM5
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
Li-Ion
Cell
Marking
UFB
UFA
Part Number
Pb-Free
MIC2778-2YM5
MIC2778-1YM5
604k
1%
56k
1%
340k
1%
Cellular Telephone Battery Monitor
V
V
VDD
LTH
HTH
BAT(hi)
BAT(lo)
MIC2778
= 3.6V
= 3.1V
GND
R S T
Marking
UFB*
UFA*
1
100k
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 1µA typical supply current
• For applications not requiring built-in delay, see MIC841
• 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
MIC5207-3.0BM5
and other battery-powered devices
low-voltage thresholds
IN
E N
Accurary
2%
1%
GND
OUT
B Y P
470pF
Temperature Range
MIC2778
-40°C to +85°C
-40°C to +85°C
V
3.0V
4.7µF
OUT
SOT-23-5
SOT-23-5
Package
M9999-011405
Micrel

Related parts for MIC2778-2BM5

MIC2778-2BM5 Summary of contents

Page 1

... A high-precision 1% grade is available. The MIC2778 is sup- plied in Micrel’s IttyBitty™ 5-lead SOT-23-5 package. Ordering Information Part Number Standard Marking Pb-Free MIC2778-2BM5 UFB MIC2778-2YM5 MIC2778-1BM5 UFA MIC2778-1YM5 * Underscore indicates a Pb-Free part. Typical Application Li-Ion Cell IttyBitty™ ...

Page 2

... MIC2778 Pin Configuration Pin Description Pin Number Pin Name 1 HTH 2 GND 3 LTH 4 RST 5 VDD M9999-011405 LTH GND HTH VDD SOT-23-5 (M5) Pin Function High-Voltage Theshold (Input): Analog input to a comparator. When the level on this pin initially rises above V ...

Page 3

... V SINK V HTH V LTH RST V RSTH V RSTL Propagation delays not shown for clarity. Note A. The MIC2778 ignores very brief transients. See “Applications Information” for details. 3 (Note 2) ) .................................. +1.5V to +5. ................–0.3V to +6.0V RST LTH HTH ) .............. –40°C to +85°C A Min Typ ...

Page 4

... Voltage Low Output The voltage-low output (RST active-low, open-drain output which sinks current when the MIC2778 detects a low input voltage. M9999-011405 Low-Voltage Detect ...

Page 5

... Some microprocessors have reset signal pins that are bidi- rectional, rather than input only. The Motorola 68HC11 family is one example. Because the MIC2778’s output is open drain, it can be connected directly to the processor’s reset pin using only the pull-up resistor normally required. See Figure 3. ...

Page 6

... MIC2778 Package Information MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA + 1 (408) 944-0800 TEL This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to the customer. ...

Related keywords