MIC812SUY [MICREL]
Microprocessor Reset Circuits;型号: | MIC812SUY |
厂家: | MICREL SEMICONDUCTOR |
描述: | Microprocessor Reset Circuits |
文件: | 总7页 (文件大小:227K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
MIC811/812
Microprocessor Reset Circuits
General Description
Features
The MIC811 and MIC812 are inexpensive microprocessor
supervisory circuits that monitor power supplies in
microprocessor based systems.
• Precision voltage monitor for 3V, 3.3V or 5V power
supplies
• /RESET remains valid with VCC as low as 1V
• 5μA typical supply current
• 140ms minimum reset pulse width available
• Manual reset input
The function of this device is to assert a reset if either the
power supply drops below a designated reset threshold
level or /MR is forced low. Several different reset threshold
levels are available to accommodate 3V, 3.3V or 5V
powered systems.
• Available in 4-pin SOT-143 package
Applications
The MIC811 has an active low /RESET output, while the
MIC812 offers an active high RESET output. The reset
output is guaranteed to remain asserted for a minimum of
140ms after VCC has risen above the designed reset
threshold level. Having a push-pull output stage, the
MIC811/812 does not require a pull-up resistor at the
output. The MIC811/812 comes in a 4-pin SOT-143
package.
• Portable equipment
• Intelligent instruments
• Critical microprocessor power monitoring
• Printers/computers
• Controllers
If a microprocessor voltage supervisor with an open-drain
output stage is needed, see MIC6315.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Typical Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
Revision 2.0
September 9, 2014
Micrel, Inc.
MIC811/812
Ordering Information
Part Number
Pb-Free
Marking(1)
Threshold Voltage
Operating Temp. Range
Package
MIC811LUY
MIC811MUY
MIC811JUY
MIC811TUY
MIC811SUY
MIC811RUY
MIC812LUY
MIC812MUY
MIC812JUY
MIC812TUY
MIC812SUY
MIC812RUY
KL
KM
KJ
KT
KS
KR
LL
4.63
4.38
4.00
3.08
2.93
2.63
4.63
4.38
4.00
3.08
2.93
2.63
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
4-pin SOT-143
LM
LJ
LT
LS
LR
Note:
1. “_” underbar symbol not to scale
Pin Configuration
MIC811 4-Pin SOT-143 (U)
MIC812 4-Pin SOT-143 (U)
Pin Description
MIC811
MIC812
Pin Name
Pin Name
1
1
GND
IC Ground Pin.
/RESET goes low if VCC falls below the reset threshold and remains asserted
for one reset timeout period (140ms min.) after VCC exceeds the reset
threshold.
2
N/A
2
/RESET
RESET
RESET goes high if VCC falls below the reset threshold and remains asserted
for one reset timeout period (140ms min.) after VCC exceeds the reset
threshold.
N/A
Manual Reset Input. A logic low on /MR will force a reset. The reset will
remain asserted as long as /MR is held low and for one reset timeout period
(140ms min.) after /MR goes high. This input can be shorted to ground via a
switch or driven from CMOS or TTL logic. Float if unused.
3
4
3
4
/MR
VCC
Power Supply Input.
Revision 2.0
September 9, 2014
2
Micrel, Inc.
MIC811/812
Absolute Maximum Ratings(2)
Operating Ratings(3)
Terminal Voltage (VCC)................................-0.3V to +6.0V
Input Current (VCC, /MR)............................................20mA
Output Current (/RESET, RESET)..............................20mA
Lead Temperature (soldering, 10s)............................ 300°C
Storage Temperature (Ts)...............................5°C to 150°C
Rate of Rise (VCC) .................................................100V/µs
ESD Rating(4)..................................................................3kV
Operating Temperature Range
MIC811 .................................................–40°C to +85°C
MIC812 .................................................–40°C to +85°C
Power Dissipation (TA = +70°C) ...............................320mW
Thermal Resistance
SOT-143 (θJA)..................................................265°C/W
Electrical Characteristics(5)
For typical values, VCC = 5V for MIC8_L/M/J, VCC = 3.3V for MIC8_S/T, VCC = 3V for MIC8_R; TA = 25°C, bold values indicate –
40°C to ≤ TA ≤ +85°C; unless noted.
Symbol Parameter
Condition
Min
1
Typ
Max
5.5
15
Units
V
VCC
Operating Voltage Range
TA = –40°C to 85°C
5
5
µA
MIC811L/M/J, MIC812L/M/J: VCC = 5.0V,
no load
10
IVCC
Supply Current
µA
MIC811S/T, MIC812S/T: VCC = 3.3V, no
load
5
10
µA
V
MIC811R, MIC812R: VCC = 3.0V, no load
MIC811L, MIC812L
4.50
4.25
4.63
4.38
4.00
3.08
2.93
2.63
240
4.75
4.50
4.10
3.15
3.00
2.70
560
MIC811M, MIC812M
V
MIC811J, MIC812J
3.89
V
VTH
Reset Voltage Threshold
MIC811T, MIC812T
3.00
V
MIC811S, MIC812S
2.85
V
MIC811R, MIC812R
2.55
V
tRST
VOH
Reset Timeout Period
/RESET Output Voltage
140
ms
V
VCC–1.5V
0.8xVCC
ISOURCE = 800µA, MIC811L/M/J
V
ISOURCE = 500µA, MIC811R/S/T
0.4
0.3
V
VCC = VTH min., ISINK = 3.2mA, MIC811L/M/J
V
VCC = VTH min., ISINK = 1.2mA,
MIC811R/S/T
VOL
/RESET Output Voltage
0.3
V
V
V
V
VCC >1V, ISINK = 50µA, TA = –40°C to +85°C
1.8V <VCC <VTH min., ISOURCE = 150µA
0.8xVCC
VOH
RESET Output Voltage
RESET Output Voltage
0.4
0.3
I
SINK = 3.2mA, MIC812L/M/J
VOL
ISINK = 1.2mA, MIC812R/S/T
Notes:
2. Exceeding the absolute maximum ratings may damage the device.
3. The device is not guaranteed to function outside its operating ratings.
4. Devices are ESD sensitive. Handling precautions are recommended. Human body model, 1.5kΩ in series with 100pF.
5. Specification for packaged product only
Revision 2.0
September 9, 2014
3
Micrel, Inc.
MIC811/812
Electrical Characteristics (Continued)(5)
For typical values, VCC = 5V for MIC8_L/M/J, VCC = 3.3V for MIC8_S/T, VCC = 3V for MIC8_R; TA = 25°C, bold values indicate –40°C to
≤ TA ≤ +85°C; unless noted.
Symbol Parameter
/MR Minimum Pulse Width
Condition
Min
10
Typ
Max
Units
µs
µs
V
0.5
/MR to Reset Delay
/MR Input Threshold
VIH
VIL
VCC > VTH max., MIC81_L/M/J
MIC81_R/S/T
2.3
0.7xVCC
V
/MR Input Threshold
VCC > VTH max., MIC81-L/M/J
MIC81_R/S/T
0.8
0.25xVCC
30
V
V
10
20
/MR Pull-Up Resistance
/MR Glitch Immunity
kΩ
ns
100
Timing Diagram
Reset Timing Diagram
Functional Diagram
Revision 2.0
September 9, 2014
4
Micrel, Inc.
MIC811/812
/RESET Valid at Low Voltage
Application Information
A resistor can be added from the /RESET pin to ground
to ensure the /RESET output remains low with VCC down
to 0V. A 100kΩ resistor connected from the /RESET to
ground is recommended. The size of the resistor should
be large enough not to load the output excessively and
small enough to pull-down any stray leakage currents.
Microprocessor Reset
The /RESET (or RESET) pin is asserted whenever VCC
falls below the reset threshold voltage. The /RESET pin
remains asserted for a period of 140ms after VCC has
risen above the reset threshold voltage. The reset
function ensures that the microprocessor is properly reset
and powers up in a known condition after a power failure.
/RESET will remain valid with VCC as low as 1V.
VCC Transients
The MIC811/812 are relatively immune to negative-going
VCC glitches below the reset threshold. Typically, a
negative-going transient 125mV below the reset
threshold with a duration of 20μs or less will not cause a
reset.
Interfacing to Bidirectional Reset Pins
The MIC811/812 can interface with µPs with bidirectional
reset pins by connecting a 4.7kΩ resistor in series with
the MIC811/812 output and the µP reset pin.
Reset Valid to VCC = 0V
Revision 2.0
September 9, 2014
5
Micrel, Inc.
MIC811/812
Package Information
4-Pin SOT-143 (U)
Revision 2.0
September 9, 2014
6
Micrel, Inc.
MIC811/812
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel, Inc. is a leading global manufacturer of IC solutions for the worldwide high performance linear and power, LAN, and timing &
communications markets. The Company’s products include advanced mixed-signal, analog & power semiconductors; high-
performance communication, clock management, MEMs-based clock oscillators & crystal-less clock generators, Ethernet switches,
and physical layer transceiver ICs. Company customers include leading manufacturers of enterprise, consumer, industrial, mobile,
telecommunications, automotive, and computer products. Corporation headquarters and state-of-the-art wafer fabrication facilities are
located in San Jose, CA, with regional sales and support offices and advanced technology design centers situated throughout the
Americas, Europe, and Asia. Additionally, the Company maintains an extensive network of distributors and reps worldwide.
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this
datasheet. This information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the
right to change circuitry, specifications and descriptions at any time without notice. No license, whether express, implied, arising by
estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Micrel’s terms and
conditions of sale for such products, Micrel assumes no liability whatsoever, and Micrel disclaims any express or implied warranty
relating to the sale and/or use of Micrel products including liability or warranties relating to fitness for a particular purpose,
merchantability, or infringement of any patent, copyright, or other intellectual property right.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where
malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or
systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be
reasonably expected to result in a significant injury to the user. A Purchaser’s use or sale of Micrel Products for use in life support
appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully indemnify Micrel for any damages resulting
from such use or sale.”
© 2014 Micrel, Incorporated.
Revision 2.0
September 9, 2014
7
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