MAX6800UR29D3-T - Maxim Integrated

General Description

The MAX6800/MAX6801/MAX6802 microprocessor (μP)

supervisory circuits monitor the power supplies in 2.85V to

5.0V μP and digital systems. They increase circuit reliability

and reduce cost by eliminating external components and

adjustments.

These devices perform a single function—they assert a

reset signal whenever the VCC supply voltage declines

below a preset threshold, keeping it asserted for a preset

timeout period after VCC has risen above the reset

threshold. The only difference among the three devices

is their output. The MAX6801 (push/pull) and MAX6802

(open-drain) have an active-low RESET output, while the

MAX6800 (push/pull) has an active-high RESET output.

The devices are guaranteed to be in the correct state for

VCC down to 0.7V. The MAX6802 is guaranteed to be in

the correct state for VCC down to 1.0V.

The reset comparator in these ICs is designed to ignore

fast transients on VCC. Reset thresholds are factory-

trimmable between 2.63V and 4.80V, in approximately

100mV increments. These devices are available with

a 1ms (min), 20ms (min), or 100ms (min) reset pulse

width. Ideal for space-critical applications, the MAX6800/

MAX6801/MAX6802 come packaged in a 3-pin SOT23.

For a lower threshold voltage version, see the MAX6332/

MAX6333/MAX6334.

Applications

●Computers

●Controllers

● Intelligent Instruments

● Critical μP/μC Power Monitoring

● Portable/Battery-Powered Equipment

Benets and Features

● Ultra-Low 0.7V Operating Supply Voltage

● Low 4.0μA Supply Current

● Precision Monitoring of 2.85V to 5.0V Power-

Supply Voltages

● Reset Thresholds Available from 2.63V to 4.80V, in

Approximately 100mV Increments

● Fully Specified over Temperature

● Three Power-On Reset Timeout Periods Available

(1ms min, 20ms min, 100ms min)

● Low Cost

● Three Available Output Structures: Push/Pull

RESET, Push/Pull RESET, Open-Drain RESET

● Guaranteed RESET/RESET Valid to VCC = 0.7V

(MAX6800/MAX6801)

● Power-Supply Transient Immunity

● No External Components Required

● 3-Pin SOT23 Package

● Pin-Compatible with MAX809/MAX810,

MAX6326/MAX6327/MAX6328, and

MAX6346/MAX6347/MAX6348

19-1933; Rev 5; 2/16

Selector Guide (Standard Versions*) appears at end of data sheet.

Typical Operating Circuit

MAX6801

VCC

RESET RESET

GND

VCC

GND

µP

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

Terminal Voltage (with respect to GND)

VCC ...................................................................... -0.3V to +6V

Push/Pull RESET, RESET .................... -0.3V to (VCC + 0.3V)

Open-Drain RESET .............................................-0.3V to +6V

Input Current (VCC) ............................................................ 20mA

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

Continuous Power Dissipation (TA = +70°C)

3-Pin SOT23 (derate 4mW/°C above +70°C) .............320mW

Operating Temperature Range ......................... -40°C to +125°C

Junction Temperature ...................................................... +150°C

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

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

Soldering Temperature (reflow) ....................................... +300°C

Lead (Pb)-free packages ............................................. +260°C

Package containing lead (Pb) ..................................... +240°C

(VCC = full range, TA = -40°C to +125°C, unless otherwise noted. Typical values are at VCC = +5.0V and TA = +25°C, reset not

asserted.) (Note 1)

Note 1: All parts are production tested at TA = +25°C. Overtemperature limits are guaranteed by design and not production tested.

Note 2: I

SOURCE for the MAX6800 is 100nA. ISINK for the MAX6801 is 100nA. ISINK for the MAX6802 is 50μA.

Absolute Maximum Ratings

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these

or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect

device reliability.

Electrical Characteristics

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range

(Note 2) VCC

TA = 0°C to +125°C MAX6800/MAX6801 0.7 5.5

MAX6802 1.0 5.5

TA = -40°C to +125°C MAX6800/MAX6801 0.78 5.5

MAX6802 1.2 5.5

Supply Current ICC No load VCC = +3.0V 4 10 µA

VCC = +5.0V 5 12

Reset Threshold VTH MAX680_UR_ _D_-T,

Table 1

TA = +25°C VTH

- 1.8% VTH

VTH

+ 1.8% V

TA = -40°C to +125°C VTH

- 3% VTH

VTH

+ 3%

VCC Falling Reset Delay VCC falling at 10V/ms 30 µs

Reset Active Timeout Period tRP

MAX680_UR_ _D1-T 1 1.5 2

msMAX680_UR_ _D2-T 20 30 40

MAX680_UR_ _D3-T 100 150 200

RESET Output Low-Voltage

(MAX6801/MAX6802) VOL Reset

asserted

ISINK = 50µA, VCC ≥ 1.0V 0.4

VISINK = 1.2mA, VCC ≥ 2.5V 0.3

ISINK = 1.2mA, VCC ≥ 4.25V 0.4

RESET Output High-Voltage

(MAX6801) VOH Reset not

asserted

ISOURCE = 500µA, VCC ≥ 3.0V 0.8 x VCC V

ISOURCE = 800µA, VCC ≥ 5.0V 0.8 x VCC

RESET Output Voltage

(MAX6800)

VOH Reset

asserted

ISOURCE = 1µA, VCC ≥ 1.0V 0.8 x VCC

ISOURCE = 200µA, VCC ≥ 1.8V 0.8 x VCC

ISOURCE = 800µA, VCC ≥ 4.25V 0.8 x VCC

VOL Reset not

asserted

ISINK = 1.2mA, VCC ≥ 3.0V 0.3

ISINK = 3.2mA, VCC ≥ 5.0V 0.4

RESET Output Leakage Current

(MAX6802) VCC > VTH, RESET not asserted 0.5 µA

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

www.maximintegrated.com Maxim Integrated

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(Reset not asserted, TA = +25°C, unless otherwise noted.)

Typical Operating Characteristics

0.950

0.980

0.970

0.960

1.000

0.990

1.040

1.030

1.020

1.010

1.050

-50 -25 0 25 50 75 100 125

NORMALIZED RESET TIMEOUT PERIOD

vs. TEMPERATURE

MAX6800/01/02 toc02

TEMPERATURE (°C)

NORMALIZED RESET TIMEOUT PERIOD

1.0 1.5 2.0 2.5 3.0

RESET (VOL)

vs. SUPPLY VOLTAGE

MAX6800/01/02 toc03

VCC (V)

OUTPUT VOLTAGE LOW (mV)

TA = +125°C

TA = +85°C

TA = +25°C

TA = -40°C

VTH = 2.93V

ISINK = 500mA

RESET ASSERTED

MAX6801/MAX6802

100

1.0 2.01.5 2.5 3.0

RESET (VOH)

vs. SUPPLY VOLTAGE

MAX6800/01/02 toc04

VCC (V)

OUTPUT VOLTAGE HIGH (VCC - VOH) (mV)

TA = +25°C

TA = -40°C

TA = +125°C

TA = +85°C

VTH = 2.93V

ISOURCE = 100A

RESET ASSERTED

(MAX6800)

100 1000

100

200

400

300

500

600

0.1 1 10

MAXIMUM TRANSIENT DURATION

vs. RESET COMPARATOR OVERDRIVE

MAX6800/01/02 toc05

RESET COMPARATOR OVERDRIVE (mV)

MAXIMUM TRANSIENT DURATION (µs)

RESET OCCURS

RESET DOES

NOT OCCUR

100

-50 -25 0 25 50 75 100 125

VCC FALLING PROPAGATION DELAY

vs. TEMPERATURE

MAX6800/01/02 toc06

TEMPERATURE (°C)

PROPAGATION DELAY (µs)

VCC = FALLING AT 1V/ms

VCC = FALLING AT 10V/ms

3.0

4.0

3.5

5.0

4.5

6.0

5.5

6.5

-50 0 25-25 50 75 100 125

SUPPLY CURRENT vs. TEMPERATURE

MAX6800/01/02 toc01

TEMPERATURE (°C)

(µA)

VCC = +5.0V

VCC = +3.3V

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

Maxim Integrated

│

www.maximintegrated.com

Pin Description

NAME FUNCTION

MAX6800 MAX6801/

MAX6802

1 1 GND Ground

—2RESET

Active-Low Reset Output. RESET is asserted while VCC is below the reset

threshold and remains asserted for a reset timeout period (tRP) after VCC

rises above the reset threshold. RESET on the MAX6801 is push/pull.

RESET on the MAX6802 is open-drain.

2— RESET

Active-High Reset Output. RESET is asserted while VCC is below the reset

threshold and remains asserted for a reset timeout period (tRP) after VCC

rises above the reset threshold. RESET on the MAX6800 is push/pull.

3 3 VCC Supply Voltage Input

Pin Conguration

TOP VIEW

3VCC

RESET (RESET)

MAX6800

MAX6801

MAX6802

SOT23-3

( ) ARE FOR MAX6800

GND

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

www.maximintegrated.com Maxim Integrated

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Applications Information

Interfacing to μPs with Bidirectional

Reset Pins

Since the RESET output on the MAX6802 is open-

drain, this device interfaces easily with μPs that have

bidirectional reset pins, such as the Motorola 68HC11.

Connecting the μP supervisor’s RESET output directly to

the microcontroller’s (μC’s) RESET pin with a single pullup

resistor allows either device to assert reset (Figure 1).

Negative-Going VCC Transients

In addition to issuing a reset to the μP during

power-up, power-down, and brownout conditions, these

devices are relatively immune to short-duration, negative-

going VCC transients (glitches). The Typical Operating

Characteristics show the Maximum Transient Duration

vs. Reset Comparator Overdrive graph. The graph shows

the maximum pulse width that a negative-going VCC

transient may typically have without issuing a reset signal.

As the amplitude of the transient increases, the maximum

allowable pulse width decreases.

Ensuring a Valid Reset Output Down to

VCC = 0V

When VCC falls below 1V and approaches the minimum

operating voltage of 0.7V, push/pull-structured reset

sinking (or sourcing) capabilities decrease drastically.

High-impedance CMOS-logic inputs connected to the

RESET pin can drift to indeterminate voltages. This does

not present a problem in most cases, since most μPs and

circuitry do not operate when VCC drops below 1V. For

the MAX6801 application, where RESET must be valid

down to 0V, adding a pulldown resistor between RESET

and GND removes stray leakage currents, holding RESET

low (Figure 2a). The pulldown resistor value is not critical;

100kΩ is large enough not to load RESET and small

enough to pull it low. For the MAX6800 application, where

RESET must be valid to VCC = 0V, a 100kΩ pullup resistor

between RESET and VCC will hold RESET high when

VCC falls below 0.7V (Figure 2b).

Since the MAX6802 has an open-drain, active-low output,

it typically uses a pullup resistor. With this device, RESET

will most likely not maintain an active condition, but will

drift to a non-active level due to the pullup resistor and

the reduced sinking capability of the open-drain device.

Therefore, this device is not recommended for applications

where the RESET pin is required to be valid down to VCC = 0V.

Figure 1. Interfacing to μPs with Bidirectional Reset Pins

VCC

GND

MAX6802

RESET

VCC

GND

RESET

MOTOROLA

68HCXX

µP

100kΩ

Figure 2. Ensuring Reset Valid Down to VCC = 0V

VCC

GND

MAX6801

RESET

100kΩ

(a)

VCC

GND

MAX6800

RESET

100kΩ*

(b)

*ASSUMES HIGH-Z RESET INPUT TO THE µP

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

www.maximintegrated.com Maxim Integrated

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Table 1. Factory-Trimmed Reset Thresholds

RESET

THRESHOLD

SUFFIX

TA = +25°C TA = -40°C to +125°C

MIN TYP (VTH)MAX MIN MAX

48 4.714 4.80 4.886 4.656 4.944

47 4.615 4.70 4.785 4.559 4.841

46 4.547 4.63 4.713 4.491 4.769

45 4.419 4.50 4.581 4.365 4.635

44 4.301 4.38 4.459 4.249 4.511

43 4.223 4.30 4.377 4.171 4.429

42 4.124 4.20 4.276 4.074 4.326

41 4.026 4.10 4.174 3.977 4.223

40 3.928 4.00 4.072 3.880 4.120

39 3.830 3.90 3.970 3.783 4.017

38 3.732 3.80 3.868 3.686 3.914

37 3.633 3.70 3.767 3.589 3.811

36 3.535 3.60 3.665 3.492 3.708

35 3.437 3.50 3.563 3.395 3.605

34 3.339 3.40 3.461 3.298 3.502

33 3.241 3.30 3.359 3.201 3.399

32 3.142 3.20 3.258 3.104 3.296

31 3.025 3.08 3.135 2.988 3.172

30 2.946 3.00 3.054 2.910 3.090

29 2.877 2.93 2.983 2.842 3.018

28 2.750 2.80 2.850 2.716 2.884

27 2.651 2.70 2.749 2.619 2.781

26 2.583 2.63 2.677 2.551 2.709

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

www.maximintegrated.com Maxim Integrated

│

*Sample stock is generally held on all standard versions.

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

Chip Information

PROCESS: BiCMOS

Selector Guide (Standard Versions*)

PART OUTPUT STAGE NOMINAL VTH (V) MIN RESET

TIMEOUT (ms)

SOT

TOP MARK

MAX6800UR26D3-T Push/Pull RESET 2.63 100 FZIE

MAX6800UR29D3-T Push/Pull RESET 2.93 100 FZIF

MAX6800UR31D3-T Push/Pull RESET 3.08 100 FZIG

MAX6800UR44D3-T Push/Pull RESET 4.38 100 FZIH

MAX6800UR46D3-T Push/Pull RESET 4.63 100 FZII

MAX6801UR26D3-T Push/Pull RESET 2.63 100 FZIK

MAX6801UR29D3-T Push/Pull RESET 2.93 100 FZIM

MAX6801UR31D3-T Push/Pull RESET 3.08 100 FZIN

MAX6801UR44D3-T Push/Pull RESET 4.38 100 FZIO

MAX6801UR46D3-T Push/Pull RESET 4.63 100 FZIP

MAX6802UR26D3-T Open-Drain RESET 2.63 100 FZIQ

MAX6802UR29D3-T Open-Drain RESET 2.93 100 FZIR

MAX6802UR31D3-T Open-Drain RESET 3.08 100 FZIS

MAX6802UR44D3-T Open-Drain RESET 4.38 100 FZIT

MAX6802UR46D3-T Open-Drain RESET 4.63 100 FZIU

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

3 SOT23 U3-1 21-0051 90-0179

*These devices are available in factory-set VCC reset thresh-

olds from 2.63V to 4.80V, in approximately 0.1V increments.

Choose the desired reset threshold suffix from Table 1 and

insert it in the blanks following “UR” in the part number.

Factory-programmed reset timeout periods are also available.

Insert the number corresponding to the desired nominal reset

timeout period (1 = 1ms min, 2 = 20ms min, 3 = 100ms min) in

the blank following “D” in the part number. There are 15 stan-

dard versions with a required order increment of 2500 pieces.

Sample stock is generally held on the standard versions only

(see Selector Guide). Contact the factory for availability of non-

standard versions (required order increment is 10,000 pieces).

All devices available in tape-and-reel only.

Devices are available in both leaded and lead-free packaging.

Specify lead-free by replacing “-T” with “+T” when ordering.

Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX6800UR_ _D_-T -40°C to +125°C 3 SOT23

MAX6801UR_ _D_-T -40°C to +125°C 3 SOT23

MAX6802UR_ _D_-T -40°C to +125°C 3 SOT23

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

www.maximintegrated.com Maxim Integrated

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Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

310/11 Added automotive-qualied part information to Ordering Information. 1

4 3/12 Updated Factory-Trimmed Reset Thresholds table. 5

5 2/16 Updated Ordering Information table 1

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses

are implied. Maxim Integrated reserves the right to change the circuitry and specications without notice at any time. The parametric values (min and max limits)

shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.

MAX6800/MAX6801/

MAX6802

3-Pin, Low-Power

μP Reset Circuits

│

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.