MIC809/810

Microprocessor Reset Circuits

General Description

The MIC809 and MIC810 are inexpensive microprocessor

supervisory

circuits

that

monitor

power

supplies

in

microprocessor-based systems.

The function of these devices is to assert a reset if the

power supply drops below a designated reset threshold

level. Several different reset threshold levels are available

to accommodate 3V, 3.3V or 5V powered systems.

The MIC809 has an active-low /RESET output, while the

MIC810 offers an active-high RESET output. The reset

output is guaranteed to remain asserted for a minimum of

threshold level. Having a push-pull output stage, the

MIC809/810 does not require a pull-up resistor at the

output. The MIC809/810 comes in a 3-pin SOT-23 and

SC-70 package.

The MIC809 is also available with a shorter reset timeout

(30ms, minimum).

Datasheets and support documentation are available on

Micrel’s web site at: www.micrel.com.

Features

• Precision voltage monitor for 3V, 3.3V, or 5V power

supplies

• /RESET remains valid with V

CC

as low as 1.4V for

SOT-23 packaged part

• /RESET remains valid with V

CC

as low as 1V for

SC70-packaged part

• Typically less than

15μA supply current for SOT-23

packaged part

• 5µA (typical) supply current for SC70-packaged part

• 140ms (minimum) reset pulse widths available

• Available in 3-pin SOT-23 and SC-70 package

Applications

• Portable equipment

• Intelligent instruments

• Critical microprocessor power monitoring

• Printers/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

July 6, 2015

Revision 3.0