MAX6332UR25D1+T - Maxim

General Description

The MAX6332/MAX6333/MAX6334 microprocessor (µP)

supervisory circuits monitor the power supplies in 1.8V

to 3.3V µP and digital systems. They increase circuit

reliability and reduce cost by eliminating external com-

ponents 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 MAX6333 (push/pull) and MAX6334

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

MAX6332 (push/pull) has an active-high RESET output.

The MAX6332/MAX6333 are guaranteed to be in the cor-

rect state for VCC down to 0.7V. The MAX6334 is guaran-

teed 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 1.6V and 2.5V, in approximately

100mV increments. There are 15 standard versions

available (2,500 piece minimum-order quantity); con-

tact the factory for availability of nonstandard versions

(10,000 piece minimum-order quantity). For space-criti-

cal applications, the MAX6332/MAX6333/MAX6334

come packaged in a 3-pin SOT23.

Applications

Pentium®II Computers

Computers

Controllers

Intelligent Instruments

Critical µP/µC Power Monitoring

Portable/Battery-Powered Equipment

Automotive

Features

oUltra-Low 0.7V Operating Supply Voltage

oLow 3.3µA Supply Current

oPrecision Monitoring of 1.8V and 2.5V Power-

Supply Voltages

oReset Thresholds Available from 1.6V to 2.5V,

in Approximately 100mV Increments

oFully Specified over Temperature

oThree Power-On Reset Pulse Widths Available

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

oLow Cost

oThree Available Output Structures: Push/Pull

RESET, Push/Pull RESET, Open-Drain RESET

oGuaranteed RESET/RESET Valid to VCC = 0.7V

(MAX6332/MAX6333)

oPower-Supply Transient Immunity

oNo External Components

o3-Pin SOT23 Package

oPin Compatible with MAX809/MAX810 and

MAX6326/MAX6327/MAX6328

MAX6332/MAX6333/MAX6334

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

19-1411; Rev 3; 6/12

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

These devices are available in factory-set V

reset thresh-

olds from 1.6V to 2.5V, 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.

/V denotes an automotive qualified part.

Typical Operating Circuit and Pin Configuration appear

at end of data sheet.

Selector Guide appears at end of data sheet.

Pentium is a registered trademark of Intel Corp.

PART TEMP RANGE PIN-PACKAGE

MAX6332UR__D_-T -40°C to +125°C 3 SOT23

MAX6333UR__D_-T -40°C to +125°C 3 SOT23

MAX6333UR__D_/V-T -40°C to +125°C 3 SOT23

MAX6334UR__D_-T -40°C to +125°C 3 SOT23

MAX6332/MAX6333/MAX6334

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC = full range, TA= -40°C to +125°C, unless otherwise noted. Typical values are at TA= +25°C and VCC = 3V, reset not asserted.)

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.

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)

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

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

Storage Temperature Range .............................-65°C to +160°C

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

Soldering Temperature (reflow)

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

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range VCC

TA= 0°C to +85°C MAX6332/MAX6333 0.7 5.5

Supply Current ICC No load VCC = 1.8V 3.0 6.0

VCC = 2.5V 3.3 7.0 µA

TA = +25°C VTH - VTH VTH +

1.8% 1.8%

TA = -40°C to +125°C VTH - VTH VTH +

3% 3%

Reset Threshold VTH MAX633_UR__D_-T,

Table 1 V

VCC Falling Reset Delay VCC falling at 10V/ms 24 µs

MAX633_UR__D1-T 1 1.5 2

MAX633_UR__D2-T 20 30 40

Reset Active Timeout Period tRP

MAX633_UR__D3-T 100 150 200

RESET Output Low Voltage

(MAX6333/MAX6334) VOL

0.4

Reset

asserted V

RESET Output High Voltage

(MAX6333) VOH

ISOURCE = 200µA, VCC ≥1.8V 0.8VCC

ISOURCE = 500µA, VCC ≥2.7V 0.8VCC

RESET Output Voltage

(MAX6332)

VOH Reset

asserted

ISOURCE = 1µA, VCC ≥1.0V 0.8VCC

ISOURCE = 200µA, VCC ≥1.8V 0.8VCC

VOL Reset not

asserted

ISINK = 500µA, VCC ≥1.8V

ISINK = 1.2mA, VCC ≥2.7V

0.3 V

0.3

Reset not

asserted

ISINK = 50µA, VCC ≥1.0V

ISINK = 500µA, VCC ≥1.8V 0.3

RESET Output Leakage

Current (MAX6334) VCC >V

TH, RESET deasserted 0.5 µA

TA = -40°C to +125°C

TA = -40°C to +85°C

MAX6332/MAX6333

MAX6334

MAX6332/MAX6333

1.2 5.5

0.78 5.5

1.2 5.5

1.0 5.5

MAX6334

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

2.0

2.6

2.2

3.0

3.6

3.8

3.4

3.2

4.0

-60

2.4

-40 -20 0

2.8

20 40 60 80 100

SUPPLY CURRENT vs. TEMPERATURE

MAX6332/33/34 toc-1

TEMPERATURE (°C)

ICC (µA)

RESET NOT ASSERTED

VCC = 1.8V

VCC = 2.5V

0.950

0.990

0.970

1.000

1.030

1.040

1.020

1.010

1.050

-60 -40

0.980

-20 0

0.960

20 40 60 80 100

NORMALIZED RESET TIMEOUT PERIOD

vs. TEMPERATURE

MAX6332/33/34-2

TEMPERATURE (°C)

NORMALIZED RESET TIMEOUT PERIOD

VTH = 2.2V

0.5 1.00 1.50 2.00 2.50 3.00

OUTPUT VOLTAGE LOW

vs. SUPPLY VOLTAGE

MAX6332/33/34 toc-6

VCC (V)

OUTPUT VOLTAGE LOW (mV)

VTH = 2.5V

ISINK = 500µA

RESET ASSERTED

TA = -40°C

TA = +85°C

TA = +25°C

100

120

140

160

0.5 1.0 1.250.75 1.5 1.75 2.0 2.25 2.5

OUTPUT VOLTAGE HIGH

vs. SUPPLY VOLTAGE

MAX6332/33/34 toc-5

VCC (V)

OUTPUT VOLTAGE HIGH (VCC - VOH) (mV)

VTH = 2.2V

ISOURCE = 100µA

RESET ASSERTED

TA = -40°C

TA = +85°C

TA = +25°C

100 1000

100

200

400

300

500

600

0.1 1 10

MAXIMUM TRANSIENT DURATION

vs. RESET COMPARATOR OVERDRIVE

MAX6332/33/34 toc-4

RESET COMPARATOR OVERDRIVE (mV)

MAXIMUM TRANSIENT DURATION (µs)

RESET OCCURS

RESET DOES

NOT OCCUR

-20

-60 0-40 20406080100

VCC FALLING PROPAGATION DELAY

vs. TEMPERATURE

MAX6332/33/34 toc-3

TEMPERATURE (°C)

PROPAGATION DELAY (µs)

VCC FALLING AT 10V/ms

VCC FALLING AT 1V/ms

Typical Operating Characteristics

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

MAX6332/MAX6333/MAX6334

Pin Description

NAME

GND

MAX6332

Ground1

MAX6333

MAX6334

FUNCTION

—RESET

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

threshold and for a reset timeout period (tRP) after VCC rises above the

reset threshold. RESET on the MAX6334 is open-drain.

2RESET—

Active-High Reset Output. RESET remains high while VCC is below the

reset threshold and for a reset timeout period (tRP) after VCC rises above

the reset threshold.

3 VCC

3Supply Voltage (0.7V to 5.5V)

MAX6332/MAX6333/MAX6334

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

______________ Applications Information

Interfacing to µPs with Bidirectional

Reset Pins

Since the RESET output on the MAX6334 is open-drain,

this device interfaces easily with µPs that have bidirec-

tional 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

pull-up 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 maxi-

mum pulse width that a negative-going VCC transient may

typically have without issuing a reset signal. As the ampli-

tude of the transient increases, the maximum allowable

pulse width decreases.

Ensuring a Valid Reset Output

Down to V

= 0

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 at VCC below 1V. For

the MAX6333, where RESET must be valid down to 0,

adding a pull-down resistor between RESET and GND

removes stray leakage currents, holding RESET low

(Figure 2a). The pull-down resistor value is not critical;

100kΩis large enough not to load RESET and small

enough to pull it low. For the MAX6332, where RESET

must be valid to VCC = 0, a 100kΩpull-up resistor

between RESET and VCC will hold RESET high when

VCC falls below 0.7V (Figure 2b).

Since the MAX6334 has an open-drain, active-low out-

put, it typically uses a pull-up resistor. With this device,

RESET will most likely not maintain an active condition,

but will drift to a non-active level due to the pull-up

resistor and the reduced sinking capability of the open-

drain device. Therefore, this device is not recommend-

ed for applications where the RESET pin is required to

be valid down to VCC = 0.

VCC

GND

MAX6334

RESET

VCC

GND

RESET

INPUT

MOTOROLA

68HCXX

µP

Factory-trimmed reset thresholds are available in approximately

100mV increments, with a ±1.8% room-temperature variance.

TA= +25°C TA= -40°C to +125°C

MIN TYP MAX MIN MAX

MAX633_UR25D_ 2.46 2.50 2.55 2.43 2.58

MAX633_UR24D_ 2.36 2.40 2.44 2.33 2.47

MAX633_UR23D_ 2.26 2.30 2.34 2.23 2.37

MAX633_UR22D_ 2.16 2.20 2.24 2.13 2.27

MAX633_UR21D_ 2.06 2.10 2.14 2.04 2.16

MAX633_UR20D_ 1.96 2.00 2.04 1.94 2.06

MAX633_UR19D_ 1.87 1.90 1.93 1.84 1.96

MAX633_UR18D_ 1.77 1.80 1.83 1.75 1.85

MAX633_UR17D_ 1.67 1.70 1.73 1.65 1.75

MAX633_UR16D_ 1.57 1.60 1.63 1.55 1.65

RESET-

THRESHOLD

SUFFIX

Table 1. Factory-Trimmed Reset

Thresholds*

Figure 1. Interfacing to µPs with Bidirectional Reset Pins

Figure 2. Ensuring Reset Valid Down to VCC = 0

VCC

GND

MAX6333

RESET

100k

(a)

VCC

GND

MAX6332

RESET

100k*

(b)

*ASSUMES HIGH-Z RESET INPUT TO THE µP

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

MAX6332/MAX6333/MAX6334

TOP VIEW

3VCC

RESET (RESET)

MAX6332

MAX6333

MAX6334

SOT23-3

( ) ARE FOR MAX6332

GND

Pin Configuration

Selector Guide (Standard Versions

)

PART OUTPUT STAGE NOMINAL VTH (V) MINIMUM RESET

TIMEOUT (ms) SOT TOP MARK

MAX6332UR23D3-T Push/Pull RESET 2.30 100 FZDM

MAX6332UR22D3-T Push/Pull RESET 2.20 100 FZCN

MAX6332UR20D3-T Push/Pull RESET 2.00 100 FZDL

MAX6332UR18D3-T Push/Pull RESET 1.80 100 FZCM

MAX6332UR16D3-T Push/Pull RESET 1.60 100 FZCL

MAX6333UR23D3-T Push/Pull RESET 2.30 100 FZCS

MAX6333UR22D3-T Push/Pull RESET 2.20 100 FZCR

MAX6333UR20D3-T Push/Pull RESET 2.00 100 FZCQ

MAX6333UR18D3-T Push/Pull RESET 1.80 100 FZCP

MAX6333UR16D3-T Push/Pull RESET 1.60 100 FZCO

MAX6334UR23D3-T Open-Drain RESET 2.30 100 FZDO

MAX6334UR22D3-T Open-Drain RESET 2.20 100 FZCV

MAX6334UR20D3-T Open-Drain RESET 2.00 100 FZDN

MAX6334UR18D3-T Open-Drain RESET 1.80 100 FZCU

MAX6334UR16D3-T Open-Drain RESET 1.60 100 FZCT

MAX6332

MAX6333

VCC

RESET RESET

INPUT

GND

VCC

GND

µP

(RESET)

( ) ARE FOR MAX6332

Typical Operating Circuit

Sample stock is generally held on all standard versions.

Package Information

For the latest package outline information and land patterns (footprints), go to www.maxim-ic.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 per-

tains to the package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND

PATTERN NO.

3 SOT23 U3+1 21-0051 90-0179

MAX6332/MAX6333/MAX6334

3-Pin, Ultra-Low-Voltage, Low-Power

µP Reset Circuits

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

implied. Maxim reserves the right to change the circuitry and specifications 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 Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 12/98 Initial release —

1 6/00 Revised Ordering Information, Absolute Maximum Ratings, Electrical Characteristics,

and Table 1. 1, 2, 4

2 12/05 Revised Ordering Information to add lead-free information. 1

3 6/12 Update Ordering Information with automotive part. 1