MAX809 - Beijing Estek Electronics Co., Ltd.

1

MAX809, MAX810

3-Pin Microprocessor

Reset Monitors

The MAX809 and MAX810 are cost–effective system supervisor

circuits designed to monitor VCC in digital systems and provide a reset

signal to the host processor when necessary. No external components

are required.

The reset output is driven active within 20 µsec of VCC falling

through the reset voltage threshold. Reset is maintained active for a

minimum of 140msec after VCC rises above the reset threshold. The

MAX810 has an active–high RESET output while the MAX809 has

an active–low RESET output. The output of the MAX809 is

guaranteed valid down to VCC = 1V. Both devices are available in a

SOT–23 package.

The MAX809/810 are optimized to reject fast transient glitches on

the VCC line. Low supply current of 17µA (VCC = 3.3V) makes these

devices suitable for battery powered applications.

Features

•Precision VCC Monitor for 3.0V, 3.3V, and 5.0V Supplies

•140msec Guaranteed Minimum RESET, RESET

Output Duration

•RESET Output Guaranteed to VCC = 1.0V (MAX809)

•Low 17µA Supply Current

•VCC Transient Immunity

•Small SOT–23 Package

•No External Components

•Wide Operating Temperature: –40°C to 85°C

Typical Applications

•Computers

•Embedded Systems

•Battery Powered Equipment

•Critical µP Power Supply Monitoring

VCC

PROCESSOR

RESET RESET

INPUT

MAX809

GND GND

TYPICAL APPLICATION DIAGRAM

SOT–23

(TO–236)

CASE 318

Device Package Shipping

ORDERING INFORMATION

MAX809xTR SOT–23 3000 Tape/Reel

MAX810xTR SOT–23 3000 Tape/Reel

PIN CONFIGURATION

(Top View)

3

1

2

VCC

GND

RESET

(RESET)**

SOT–23*

NOTE: *SOT–23 is equivalent to JEDEC (T O–236)

** RESET is for MAX809

** RESET is for MAX810

L 4.63

M 4.38

J* 4.00

T 3.08

S 2.93

R 2.63

Suffix Reset VCC Threshold (V)

NOTE: The ”x” denotes a suffix for VCC threshold –

see table below

NOTE: *J version is available for MAX809 only

MAX809, MAX810

2

ABSOLUTE MAXIMUM RATINGS*

Symbol Parameter Value Unit

Supply Voltage (VCC to GND) 6.0 V

RESET, RESET –0.3 to (VCC + 0.3) V

Input Current, VCC 20 mA

Output Current, RESET, RESET 20 mA

dV/dt (VCC) 100 V/µsec

PDPower Dissipation (TA ≤ 70°C)

SOT–23 (derate 4mW/°C above +70°C) 230 mW

TAOperating Temperature Range –40 to +85 °C

Tstg Storage Temperature Range –65 to +150 °C

Tsol Lead Temperature (Soldering, 10 Seconds) +260 °C

* Maximum Ratings are those values beyond which damage to the device may occur.

MAX809, MAX810

3

ELECTRICAL CHARACTERISTICS (VCC = Full Range, TA = –40°C to +85°C unless otherwise noted. typical values are at TA

= +25C, VCC = 5V for L/M/J, 3.3V for T/S, 3.0V for R) (Note NO TAG)

Symbol Characteristic Min Typ Max Unit

VCC Range

TA = 0°C to +70°C

TA = –40°C to +85°C1.0

1.2 —

—5.5

5.5

V

ICC Supply Current

MAX8xxL/M/J: VCC < 5.5V

MAX8xxR/S/T: VCC < 3.6V —

—24

17 60

50

µA

VTH Reset Threshold (Note NO TAG)

MAX8xxL: TA = 25°C

TA = –40°C to +85°C

MAX8xxM: TA = 25°C

TA = –40°C to +85°C

MAX809J: TA = 25°C

TA = –40°C to +85°C

MAX8xxT: TA = 25°C

TA = –40°C to +85°C

MAX8xxS: TA = 25°C

TA = –40°C to +85°C

MAX8xxR: TA = 25°C

TA = –40°C to +85°C

4.56

4.50

4.31

4.25

3.93

3.89

3.04

3.00

2.89

2.85

2.59

2.55

4.63

—

4.38

—

4.00

—

3.08

—

2.93

—

2.63

—

4.70

4.75

4.45

4.50

4.06

4.10

3.11

3.15

2.96

3.00

2.66

2.70

V

Reset Threshold Temperature Coefficient — 30 — ppm/°C

VCC to Reset Delay VCC = VTH to (VTH – 100mV) — 20 — µsec

Reset Active T imeout Period 140 240 560 msec

VOL RESET Output Voltage Low (MAX809)

MAX809R/S/T: VCC = VTH min, ISINK = 1.2mA

MAX809L/M/J: VCC = VTH min, ISINK = 3.2mA

VCC > 1.0V, ISINK = 50µA

—

0.3

0.4

0.3

V

VOH RESET Output Voltage High (MAX809)

MAX809R/S/T: VCC > VTH max, ISOURCE = 500µA

MAX809L/M/J: VCC > VTH max, ISOURCE = 800µA0.8 VCC

VCC – 1.5 —

——

—

V

VOL RESET Output Voltage Low (MAX810)

MAX810R/S/T: VCC = VTH max, ISINK = 1.2mA

MAX810L/M/J: VCC = VTH max, ISINK = 3.2mA —

——

—0.3

0.4

V

VOH RESET Output Voltage High (MAX810)

1.8 < VCC < VTH min, ISOURCE = 150µA0.8 VCC — — V

1. Production testing done at TA = 25°C, over temperature limits guaranteed by design.

PIN DESCRIPTION

Pin No. Symbol Description

ÁÁÁÁÁ

1

ÁÁÁÁÁÁ

GND

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Ground

ÁÁÁÁÁ

Á

ÁÁÁ

Á

ÁÁÁÁÁ

2

ÁÁÁÁÁÁ

Á

ÁÁÁÁ

Á

ÁÁÁÁÁÁ

RESET (MAX809)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Á

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Á

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

RESET output remains low while VCC is below the reset voltage threshold, and for 240msec (typ.)

after VCC rises above reset threshold

ÁÁÁÁÁ

2

ÁÁÁÁÁÁ

RESET (MAX810)

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

RESET output remains high while VCC is below the reset voltage threshold, and for 240msec (typ.)

after VCC rises above reset threshold

ÁÁÁÁÁ

3

ÁÁÁÁÁÁ

VCC

ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ

Supply Voltage (typ.)

MAX809, MAX810

4

APPLICATIONS INFORMATION

VCC Transient Rejection

The MAX809/810 provides accurate VCC monitoring and

reset timing during power–up, power–down, and

brownout/sag conditions, and rejects negative–going

transients (glitches) on the power supply line. Figure 1

shows the maximum transient duration vs. maximum

negative excursion (overdrive) for glitch rejection. Any

combination of duration and overdrive which lies under the

curve will not generate a reset signal. Combinations above

the curve are detected as a brownout or power–down.

T ransient immunity can be improved by adding a capacitor

in close proximity to the VCC pin of the MAX809/810.

Figure 1. Maximum Transient Duration vs. Overdrive

for Glitch Rejection at 25° C

Duration

VTH

Overdrive

VCC

TA = +25° C

MAX8xxL/M/J

1 10 100 1000

0

90

160

240

320

400

MAXIMUM TRANSIENT DURATION ( sec)

m

RESET COMPARATOR OVERDRIVE,

(VTH – VCC (mV)

MAX8xxR/S/T

RESET Signal Integrity During Power–Down

The MAX809 RESET output is valid to VCC = 1.0V.

Below this voltage the output becomes an ”open circuit” and

does not sink current. This means CMOS logic inputs to the

µP will be floating at an undetermined voltage. Most digital

systems are completely shutdown well above this voltage.

However, in situations where RESET must be maintained

valid to VCC = 0V, a pull–down resistor must be connected

from RESET to ground to discharge stray capacitances and

hold the output low (Figure 2). This resistor value, though

not critical, should be chosen such that it does not

appreciably load RESET under normal operation (100k

W

will be suitable for most applications). Similarly, a pull–up

resistor to VCC is required for the MAX810 to ensure a valid

high RESET for VCC below 1.0V.

VCC

RESET

R1

100 k

MAX809

GND

Figure 2. Ensuring RESET Valid to VCC = 0 V

Processors With Bidirectional I/O Pins

Some µP’s (such as Motorola 68HC11) have

bi–directional reset pins. Depending on the current drive

capability of the processor pin, an indeterminate logic level

may result if there is a logic conflict. This can be avoided

by adding a 4.7k

W

resistor in series with the output of the

MAX809/810 (Figure 3). If there are other components in

the system which require a reset signal, they should be

buffered so as not to load the reset line. If the other

components are required to follow the reset I/O of the µP, the

buffer should be connected as shown with the solid line.

VCC

m

P

RESET

MAX809

GND GND

47 k

Figure 3. Interfacing to Bidirectional Reset I/O

RESET

VCC

BUFFERED RESET

TO OTHER SYSTEM

COMPONENTS

BUFFER

MAX809, MAX810

5

TYPICAL CHARACTERISTICS

VCC = 5 V

VCC = 3 V

VCC = 1 V

TEMPERATURE (C°)

–40 –20 0 20 40 60 85

0

5

10

15

20

25

30

35

SUPPLY CURRENT ( A)

m

Figure 4. Supply Current vs Temperature

(No Load, MAX8xxR/S/T)

VCC = 5 V

VCC = 3 V

VCC = 1 V

–40 –20 0 20 40 60 85

0

5

10

15

20

30

TEMPERATURE (C°)

Figure 5. Supply Current vs Temperature

(No Load, MAX8xxL/M/J/)

VOD = VTH – VCC

VOD = 10 mV

TEMPERATURE (C°)

–40 –20 0 20 40 60 85

0

40

20

60

80

100

POWER–DOWN RESET DELAY ( sec)

m

Figure 6. Power–Down Reset Delay vs

Temperature and Overdrive (MAX8xxR/S/T)

VOD = 100 mV

VOD = 200 mV

VOD = VTH – VCC

VOD = 20 mV

TEMPERATURE (C°)

–40 –20 0 20 40 60 85

0

40

20

60

80

140

POWER–DOWN RESET DELAY ( sec)

m

Figure 7. Power–Down Reset Delay vs

Temperature and Overdrive (MAX8xxL/M/J)

VOD = 100 mV

VOD = 200 mV

100

120 VOD = 10 mV

TEMPERATURE (C°)

–40 –20 0 20 40 85

0.997

0.998

0.999

1.003

NORMALIZED THRESHOLD

1.001

1.002

Figure 8. Power–Up Reset Timeout vs

Temperature

TEMPERATURE (C°)

–40 –20 0 20 40 60 85

225

235

230

240

245

250

P

OWER

–UP

RE

S

ET TIMEO

U

T (msec

)

MAX8xxL/M/J

MAX8xxR/S/T

60

SUPPLY CURRENT ( A)

m

25

Figure 9. Normalized Reset Threshold vs

Temperature

1.000

MAX809, MAX810

6

TAPING FORM

PIN 1

USER DIRECTION OF FEED

Component Taping Orientation for 3L SOT–23 (JEDEC–236) Devices

Standard Reel Component Orientation

(Mark Right Side Up)

DEVICE

MARKING

SOT–23

Package Carrier Width (W) Pitch (P) Part Per Full Reel Reel Size

8 mm 4 mm 3000 7 inches

Tape & Reel Specifications Table

MARKING DIAGRAM

SOT–23

xxYW

YW = Date Code

MARKING

ON Semiconductor Part # Reset Threshold or Address Marking

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809L

ÁÁÁÁÁÁÁÁÁÁÁ

4.63

ÁÁÁÁÁÁÁÁÁÁÁÁ

J1YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809M

ÁÁÁÁÁÁÁÁÁÁÁ

4.38

ÁÁÁÁÁÁÁÁÁÁÁÁ

J2YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809T

ÁÁÁÁÁÁÁÁÁÁÁ

3.08

ÁÁÁÁÁÁÁÁÁÁÁÁ

J3YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809S

ÁÁÁÁÁÁÁÁÁÁÁ

2.93

ÁÁÁÁÁÁÁÁÁÁÁÁ

J4YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809R

ÁÁÁÁÁÁÁÁÁÁÁ

2.63

ÁÁÁÁÁÁÁÁÁÁÁÁ

J5YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX809J

ÁÁÁÁÁÁÁÁÁÁÁ

4.00

ÁÁÁÁÁÁÁÁÁÁÁÁ

J6YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX810L

ÁÁÁÁÁÁÁÁÁÁÁ

4.63

ÁÁÁÁÁÁÁÁÁÁÁÁ

K1YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX810M

ÁÁÁÁÁÁÁÁÁÁÁ

4.38

ÁÁÁÁÁÁÁÁÁÁÁÁ

K2YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX810T

ÁÁÁÁÁÁÁÁÁÁÁ

3.08

ÁÁÁÁÁÁÁÁÁÁÁÁ

K3YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX810S

ÁÁÁÁÁÁÁÁÁÁÁ

2.93

ÁÁÁÁÁÁÁÁÁÁÁÁ

K4YW

ÁÁÁÁÁÁÁÁÁÁÁÁ

MAX810R

ÁÁÁÁÁÁÁÁÁÁÁ

2.63

ÁÁÁÁÁÁÁÁÁÁÁÁ

K5YW

YW = Date code

MAX809, MAX810

7

PACKAGE DIMENSIONS

SOT–23

PLASTIC PACKAGE (TO–236)

CASE 318–08

ISSUE AF

DJ

K

L

A

C

BS

H

GV

3

12DIM

AMIN MAX MIN MAX

MILLIMETERS

0.1102 0.1197 2.80 3.04

INCHES

B0.0472 0.0551 1.20 1.40

C0.0350 0.0440 0.89 1.11

D0.0150 0.0200 0.37 0.50

G0.0701 0.0807 1.78 2.04

H0.0005 0.0040 0.013 0.100

J0.0034 0.0070 0.085 0.177

K0.0140 0.0285 0.35 0.69

L0.0350 0.0401 0.89 1.02

S0.0830 0.1039 2.10 2.64

V0.0177 0.0236 0.45 0.60

NOTES:

1. DIMENSIONING AND TOLERANCING PER ANSI

Y14.5M, 1982.

2. CONTROLLING DIMENSION: INCH.

3. MAXIMUM LEAD THICKNESS INCLUDES LEAD

FINISH THICKNESS. MINIMUM LEAD THICKNESS

IS THE MINIMUM THICKNESS OF BASE

MATERIAL.

MAX809, MAX810