Datasheet MIC810U, MIC809U Datasheet (MICREL)

1

The MIC809/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 accomodate 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 140ms after VCC has risen above the designated
reset threshold level. The MIC809/MIC810 come in a 3­pin SOT-23 package.

1

2

3

V

CC

GND

MIC809

RESET

1

2

3

V

CC

GND

MIC810

RESET

Top View

Part Package Temp. Range

MIC809_U 3-Lead SOT23 -40°C to +85°C

MIC810_U 3-Lead SOT23 -40°C to +85°C

Place the device suffix of desired reset threshold voltage from table above in
blank to complete the part number.

·

Portable Equipment

·

Intelligent Instruments

·

Critical Microprocessor Power Monitoring

·

Printers/Computers

·

Controllers

·

RESET Remains Valid with V

CC

as Low

as 1.4V

·

Precision Voltage Monitor for 3V, 3.3V
or 5V Power Supplies

·

Available in 3-Pin SOT23 Package

·

<15µA Supply Current

·

140ms Minimum Reset Pulse Width

·

No External Components Required

V

CC

RESET

µP

RESET

V

CC

MIC809

V

CC

Typical Operating Circuit

Features

Description Pin Configuration

Ordering Information

Typical Applications

Reset Threshold Device

Voltage (V) Suffix

4.63 L

4.38 M

4.00 J

3.08 T

2.93 S

2.63 R

MIC809/MIC810 Microprocessor Reset Circuits

MIC809/MIC810

Microprocessor Reset Circuits

MIC809/MIC810 Microprocessor Reset Circuits

2

Electrical Characteristics

VCC= 5V for MIC8--L/M/J, VCC= 3.3V for MIC8--S/T, VCC= 3V for MIC8--R, TA= Operating Temperature Range, unless
otherwise noted.

Parameter Conditions Min Typ Max Units

Operating Voltage Range, V

CC

TA= 0°C to 70°C 1.4 5.5 V
TA= -40°C to 85°C 1.6 5.5

Supply Current, I

CC

MIC809L/M/J, MIC810L/M/J 9 15 µA

VCC< 3.6V, MIC809R/S/T, MIC810R/S/T 6 10

Reset Voltage Threshold, V

TH

MIC809L, MIC810L 4.50 4.63 4.75 V
MIC809M, MIC810M 4.25 4.38 4.50
MIC809J, MIC810J 3.89 4.00 4.10
MIC809T, MIC810T 3.00 3.08 3.15
MIC809S, MIC810S 2.85 2.93 3.00
MIC809R, MIC810R 2.55 2.63 2.70

Reset Timeout Period 140 240 560 ms

RESET Output Voltage, V

OH

I

Source

= 800µA, MIC809L/M/J

VCC- 1.5V

V

I

Source

= 500µA, MIC809R/S/T 0.8 X

V

CC

RESET Output Voltage, V

OL

VCC=VTHMin., I

Sink

=3.2mA, MIC809L/M/J

0.4 V

VCC=VTHMin., I

Sink

=1.2mA, MIC809R/S/T

0.3

VCC>1.4V, I

Sink

=50µA,

TA= 0°C to 70°C 0.3

VCC>1.6V, I

Sink

=50µA,

TA= -40°C to 85°C 0.3

RESET Output Voltage, V

OH

1.8V < V

CC

< VTHMin., 0.8 X

V

CC

V

I

Source

= 150µA

RESET Output Voltage, V

OL

I

Sink

=3.2mA, MIC810L/M/J 0.4 V

I

Sink

=1.2mA, MIC810R/S/T 0.3

Stresses above those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent device failure. Functionality at or above these limits is not implied. Exposure to absolute
maximum ratings for extended periods may affect device reliability. Operating ranges define those limits between which the functionality of the device is guaranteed.

Absolute Maximum Ratings

Terminal Voltage

VCC. . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V

Input Current, VCC, . . . . . . . . . . . . . . . . . . . . . . . 20mA

Output Current, RESET, RESET . . . . . . . . . . . . . .20mA

Rate of Rise, V

CC

. . . . . . . . . . . . . . . . . . . . . . 100V/µs

Operating Temperature Range

MIC809

-

U, MIC810-U . . . . . . . . . . . . . . . -40°C to 85°C

Storage Temperature Range . . . . . . . . . . . . . -65°C to 150°C

Lead Temperature (Soldering - 10 sec.) . . . . . . . . . . . 300°C

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

MIC809/MIC810 Microprocessor Reset Circuits

Pin Functions

3

IC Ground Pin.

RESET goes low if VCCfalls below the reset threshold and remains
asserted for one reset timeout period (140ms min.) after VCCexceeds
the reset threshold.

RESET goes high if VCCfalls below the reset threshold and remains
asserted for one reset timeout period (140ms min.) after VCCexceeds
the reset threshold.

Power supply input, 3V, 3.3V or 5V.

Pin No.

Pin Name MIC809 MIC810

GND 11

RESET 2 N/A

RESET N/A 2

V

CC

33

4

+

-

Reset

Threshold (V)

VCC(3)

RESET (2)
RESET (MIC810)

GND (1)

RESET

GENERATOR

Figure 1. MIC809/810 Block Diagram

Block Diagram

MIC809/MIC810 Microprocessor Reset Circuits

5

Microprocessor Reset

The RESET pin is asserted whenever V

CC

falls below
the reset threshold voltage. The reset pin remains
asserted for a period of 240ms after VCChas 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 VCCas low as 1.4V.

VCCTransients

The MIC809/MIC810 are relatively immune to negative­going VCCglitches below the reset threshold. Typically,
a negative-going transient 125mV below the reset

threshold with a duration of 50µs (25µs for

MIC8__R/S/T) or less will not cause an unwanted reset.

Interfacing to Bidirectional Reset Pins

The MIC809/MIC810 can interface with µPs with
bidirectional reset pins by connecting a 4.7KΩ resistor in
series with the MIC809/MIC810 output and the µP reset

pin.

RESET Valid to 0V

A resistor can be added from the RESET pin to ground
to ensure the RESET output remains low with V

CC

down to 0V. A 100KΩ resistor connected from RESET

to ground is recommended. The size of the resistor
should be large enough to not load the RESET output
and small enough to pull-down any stray leakage
currents.

Circuit Description

Figure 2. Reset Timing Diagram

Figure 3. RESET Valid to VCC= OV

V

CC

V

thr

RESET

t1t1

V

thr

V

CC

RESET

µP

RESET

V

CC

MIC809

V

CC

100K

MIC809/MIC810 Microprocessor Reset Circuits

6

MIC Direct

Industry P/N Replacement

MAX809JEUR-T MIC809JU

MAX809LEUR-T MIC809LU

MAX809MEUR-T MIC809MU

MAX809REUR-T MIC809RU

MAX809SEUR-T MIC809SU

MAX809TEUR-T MIC809TU

MAX810JEUR-T MIC810JU

MAX810LEUR-T MIC810LU

MAX810MEUR-T MIC810MU

MAX810REUR-T MIC810RU

MAX810SEUR-T MIC810SU

MAX810TEUR-T MIC810TU

Alternate Source Cross Reference Guide

MIC809/MIC810 Microprocessor Reset Circuits

7

Packaging Information

0.079

0.071

0.120

0.105

0.040

0.031

0.004

0.001

0.021

0.015

0.055

0.047

0.098

0.083

0.0059

0.0035

0.010

0.005

0-8¼

U Package, 3-Pin SOT-23 Small-Outline Transistor Package

Device Marking Information

Lot Code

IJXX = MIC809J
ILXX = MIC809L
IMXX = MIC809M
IRXX = MIC809R
ISXX = MIC809S
ITXX = MIC809T
JJXX = MIC810J
JLXX = MIC810L
JMXX = MIC810M
JRXX = MIC810R
JSXX = MIC810S
JTXX = MIC810T

Dimensions are in inches.

MIC809/MIC810 Microprocessor Reset Circuits

8

Packaging Information

4.0±0.1

4.0±0.1

2.0±0.05

3.5±0.05

8.0±0.3

1.75±0.1

¯1.5±0.1

¯1.1±0.1

2.7±0.1

3.1±0.1

1.2±0.1

Tape and Reel Information

Dimensions are in millimeters.

MIC809/MIC810 Microprocessor Reset Circuits