MIC8115_15 [MICREL]

Microprocessor Reset Circuit;


型号：	MIC8115_15
厂家：	MICREL SEMICONDUCTOR
描述：	Microprocessor Reset Circuit
文件：	总7页 (文件大小：505K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MIC8115

Microprocessor Reset Circuit

General Description

Features

The MIC8115 is an inexpensive microprocessor

supervisory circuit that monitors power supplies in

microprocessor-based systems.

• Precision voltage monitor for 3.3V power supplies

• Specifically-tailored to the AMD Elan SC500 Series

• /RESET remains valid with V_CCas low as 1.4V

• <15µA supply current

• 1100ms minimum reset pulse width

• Manual reset input

The function of the MIC8115 is to assert a reset if the

power supply drops below a designated reset threshold

level or /MR is forced low.

The MIC8115 has an active low /RESET output. The reset

output is guaranteed to remain asserted for a minimum of

1100ms after V_CChas risen above the designated reset

threshold level. The MIC8115 comes in a 4-pin SOT-143

package.

• Available in 4-Pin SOT-143 Package

Applications

• Portable equipment

• Intelligent instruments

• Critical microprocessor power monitoring

• Printers/computers

Datasheets and support documentation are available on

Micrel’s web site at: www.micrel.com.

• Embedded controllers

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

August 3, 2015 Revision 2.0

Micrel, Inc.

MIC8115

Ordering Information

Part Number⁽¹⁾

Marking

Junction Temperature Range

Package

Lead Finish

Pb-Free

MIC8115-TUY

–40°C to +85°C

4-Pin SOT-143

Note:

1. Underbar (__) may not be to scale.

Pin Configuration

4-Pin SOT-143

(Top View)

Pin Description

Pin Number

Pin Name Pin Function

GND

IC Ground Pin.

/RESET goes low if either VCC falls below the supply reset threshold voltage or if /MR is asserted.

/RESET remains asserted for one reset timeout period 1100ms (minimum) after both VCC exceeds

the supply reset threshold voltage and /MR is deasserted.

/RESET

Manual Reset Input. A logic low on /MR forces a reset. The reset will remain asserted as long as /MR

is held low and for one reset timeout period (1100ms, minimum) after /MR goes high. This input can

be shorted to ground via a switch or driven from CMOS or TTL logic. Pulled high internally through a

20kΩ resistor. Float if unused.

/MR

VCC

Power Supply Input.

August 3, 2015

Revision 2.0

Micrel, Inc.

MIC8115

Absolute Maximum Ratings⁽²⁾

Operating Ratings⁽³⁾

Terminal Voltage

Operating Temperature Range.................. –40°C to +85°C

Power Dissipation (T_A= +70°C)...............................320mW

(V_CC)......................................................... –0.3V to 6.0V

(/MR) ...............................................–0.3V (V_CC+ 0.3V)

Input Current (VCC, /MR)............................................20mA

Output Current (/RESET)............................................20mA

Rate of Rise (V_CC) ...................................................100V/µs

Lead Temperature (soldering, 10s)............................ 300°C

Storage Temperature (T_S).........................–65°C to +150°C

ESD Rating⁽⁴⁾..................................................................3kV

Electrical Characteristics

For typical values, V_CC= 3.3V; T_A= 25°C, bold values indicate –40°C ≤ T_A≤ +85°C, unless noted.

Symbol

V_CC

Parameter

Condition

Min.

Typ.

Max.

5.5

Units

Operating Voltage Range

Supply Current

T_A= –40°C to +85°C

I_CC

µA

3.00

1100

3.15

2500

V_TH

Reset Voltage Threshold

Reset Timeout Period

/RESET Output Voltage

3.08

1700

I_RST

0.8 × V_CC

V_OH

I_SOURCE= 500µA

0.3

V_CC= V_TH(MIN), I_SINK= 1.2mA

V_OL

/Reset Output Voltage

V_CC= 1V, I_SINK= 50µA,

T_A= –40°C to +85°C

0.7 × V_CC

/MR Minimum Pulse Width

/MR to Reset Delay

µs

0.5

VIH

VIL

/MR Input Threshold

/MR Pull-Up Resistance

/MR Glitch Immunity

0.25 × V_CC

kΩ

100

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.

August 3, 2015

Revision 2.0

Micrel, Inc.

MIC8115

Timing Diagram

Functional Diagram

August 3, 2015

Revision 2.0

Micrel, Inc.

MIC8115

Application Information

Microprocessor Reset

The /RESET pin is asserted whenever V_CCfalls below the

reset threshold voltage. The reset pin remains asserted

for a period of 1100ms after V_CChas risen above the

reset threshold voltage. The reset function ensures the

microprocessor is properly reset and powers up into a

known condition after a power failure. /RESET will remain

valid with V_CCas low as 1.4V.

V_CCTransients

The MIC1815 is relatively immune to the negative-going

V_CCglitches below the reset threshold. Typically, a

negative- going transient 125mV belt the reset threshold

with duration of 20µs or less will not cause a reset.

/RESET Valid at Low Voltage

A resistor can be added from the /RESET pin to the

ground to ensure the /RESET output remains low with

V_CCdown to 0V. A 100kΩ resistor connected from

/RESET to ground is recommended. The resistor should

be large enough not to load the /RESET output and small

enough to pull-down any stray leakage currents.

Figure 1. /RESET Valid to V_CC= 0V

August 3, 2015

Revision 2.0

Micrel, Inc.

MIC8115

Package Information and Recommended Landing Pattern⁽⁵⁾

4-Pin SOT-143 (TU)

Note:

5. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.

August 3, 2015

Revision 2.0

Micrel, Inc.

MIC8115

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.

August 3, 2015

Revision 2.0

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