MIC705/706/707/708

µP Supervisory Circuit

General Description

The

MIC705,

MIC706,

MIC707,

and

MIC708

are

inexpensive

microprocessor

supervisory

circuits

that

monitor power supplies in microprocessor-based systems.

The

circuit

functions

include

a

watchdog

timer,

microprocessor

reset,

power-failure

warning,

and

a

debounced manual reset input.

The MIC705 and MIC706 offer a watchdog timer function

while the MIC707 and MIC708 have an active-high reset

output in addition to the active-low reset output.

Supply voltage monitor levels of 4.65V and 4.4V are

available. The MIC705 and MIC707 have a nominal reset

threshold level of 4.65V while the MIC706 and MIC708

have a 4.4V nominal reset threshold level. When the

supply voltage drops below the respective reset threshold

level, /RESET is asserted.

Datasheets and support documentation are available on

Micrel’s web site at: www.micrel.com.

Features

• Debounced manual reset input is TTL/CMOS

compatible

• Reset pulse width: 200ms

• Watchdog timer: 1.6s (MIC705/706)

• 4.65V or 4.40V precision voltage monitor

• Early power-fail warning or low-battery detect

Applications

• Automotive systems

• Intelligent systems

• Critical microprocessor power monitoring

• Battery-powered computers

• Computers

• 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

September 15, 2014

Revision 2.1