MAXIM MAX823, MAX824, MAX825 Technical data

________________General Description

The MAX823/MAX824/MAX825* microprocessor (µP)
supervisory circuits combine reset output, watchdog,
and manual reset input functions in 5-pin SOT23 and
SC70 packages. They significantly improve system relia­bility and accuracy compared to separate ICs or discrete
components. The MAX823/MAX824/MAX825 are specifi­cally designed to ignore fast transients on VCC.

Seven preprogrammed reset threshold voltages are
available (see Reset Threshold Table). All three devices
have an active-low reset output, which is guaranteed to
be in the correct state for VCCdown to 1V. The MAX823
also offers a watchdog input and manual reset input.
The MAX824 offers a watchdog input and a comple­mentary active-high reset. The MAX825 offers a manual
reset input and a complementary active-high reset. The
Selector Guide explains the functions offered in this
series of parts.

________________________Applications

Computers and Controllers
Embedded Controllers
Intelligent Instruments
Automotive Systems
Critical µP Monitoring
Portable/Battery-Powered Equipment

Features

♦ Precision Monitoring of +2.5V, +3V, +3.3V, and

+5V Power Supplies

♦ Operating Current: 6µA (MAX823L/M) (SC70)

2µA (MAX825T/S/R/Z/Y) (SC70)

♦ Fully Specified Over Temperature

♦ 140ms min Power-On Reset
♦ Guaranteed RESET Valid to VCC= 1V

♦ Power-Supply Transient Immunity

♦ Watchdog Timer with 1.6s Timeout

(MAX823/MAX824)

♦ Manual Reset Input (MAX823/MAX825)

♦ No External Components

MAX823/MAX824/MAX825

5-Pin Microprocessor Supervisory Circuits With

Watchdog Timer and Manual Reset

________________________________________________________________ Maxim Integrated Products 1

1

5

2

3

4

1

5

2

3

4

1

5

2

3

4

GND

WDI

V

CC

MAX823

SOT23/SC70

TOP VIEW

MR

RESET

GND

WDI

RESET

V

CC

MAX824

SOT23/SC70

RESET

GND

MR

RESET

V

CC

MAX825

SOT23/SC70

RESET

______________________Selector Guide

19-0487; Rev 5; 12/05

†Insert the desired suffix letter (from the Reset Threshold table) into
the blank to complete the part number. All devices are available in
tape-and-reel only. There is a 2500 piece minimum order increment.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.

MAX823

Active-Low Reset

✔

Active-High Reset —

FUNCTION

Watchdog Input

✔

MAX824

✔

✔

✔

MAX825

✔

✔

—

Manual Reset Input

✔

—

✔

SUFFIX

RESET

THRESHOLD (V)

L 4.63

M 4.38

T 3.08

S 2.93

R 2.63

Typical Operating Circuit appears at end of data sheet.
Marking Information appears at end of data sheet.

Ordering Information

PART

†

TEMP. RANGE

PIN-PACKAGE

MAX823_EXK-T

-40°C to +85°C

5 SC70-5

MAX823_EUK-T

5 SOT23-5

MAX824_EXK-T

-40°C to +85°C

5 SC70-5

Ordering Information continued at end of data sheet.

Reset Threshold Table

Z (SC70 only) 2.32

Y (SC70 only) 2.19

Pin Configurations

*Patents Pending

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

查询MAX804R供应商

-40°C to +125°C

MAX823/MAX824/MAX825

5-Pin Microprocessor Supervisory Circuits With
Watchdog Timer and Manual Reset

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +4.75V to +5.5V for MAX82_L, VCC= +4.5V to +5.5V for MAX82_M, VCC= +3.15V to +3.6V for MAX82_T, VCC= +3V
to +3.6V for MAX82_S, VCC= +2.7V to +3.6V for MAX82_R, VCC= +2.38V to +2.75V for MAX82_Z, VCC= +2.25V to +2.75V for
MAX82_Y, TA= T

MIN

to T

MAX

, TA= -40°C to +85°C (SC70), TA= -40°C to +125°C (SOT23), unless otherwise noted. Typical values

are at T

A

= +25°C.) (Note 1)

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.

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

All Other Pins..............................................-0.3V to (V

CC

+ 0.3V)

Input Current, All Pins Except RESET and RESET..............20mA

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

Continuous Power Dissipation (T

A

= +70°C)

5-Pin SC70 (derate 3.1mW/°C above +70°C)...............247mW

5-Pin SOT23 (derate 7.1mW/°C above +70°C).............571mW

Operating Temperature Range

MAX82_EXK......................................................-40°C to +85°C

MAX82_EUK ...................................................-40°C to +125°C

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

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

MAX825T/S/R/Z/Y

PARAMETER SYMBOL MIN TYP MAX UNITS

4.56 4.63 4.70

Supply Current
(SOT23 Only)

I

SUPPLY

38

µA

4.5 12

10 24

4.50 4.75

Operating Voltage Range

MAX825L/M

MAX823L/M
MAX824L/M

1.0 5.5

V

CC

1.2

V

512

MAX823T/S/R/Z/Y
MAX824T/S/R/Z/Y

2.59 2.63 2.66

2.55 2.70TA= T

MIN

to T

MAX

TA= +25°C

MAX82_R

3.04 3.08 3.11

3.00 3.15TA= T

MIN

to T

MAX

TA= +25°C

MAX82_T

2.89 2.93 2.96

2.85 3.00TA= T

MIN

to T

MAX

TA= +25°C

CONDITIONS

MAX82_S

MR unconnected

TA= T

MIN

to T

MAX

TA= +25°C

MAX82_L

4.31 4.38 4.45

TA= 0°C to +70°C

TA= T

MIN

to T

MAX

4.25 4.50

WDI and MR
unconnected

TA= T

MIN

to T

MAX

TA= +25°C

MAX82_M

MAX825T/S/R/Z/Y

Supply Current
(SC70 Only)

I

SUPPLY

26

µA

38

617

MAX825L/M

MAX823L/M
MAX824L/M

412

MAX823T/S/R/Z/Y
MAX824T/S/R/Z/Y

MR unconnected

WDI and MR
unconnected

2.28 2.32 2.35

2.25 2.38

Reset Threshold

V

TA= T

MIN

to T

MAX

TA= +25°C

MAX82_Z
(SC70 only)

2.16 2.19 2.22

2.13 2.25TA= T

MIN

to T

MAX

TA= +25°C

MAX82_Y
(SC70 only)

V

RST

MAX823/MAX824/MAX825

5-Pin Microprocessor Supervisory Circuits With

Watchdog Timer and Manual Reset

_______________________________________________________________________________________ 3

PARAMETER

CONDITIONS

UNITS

MAX82_L/M 10

Reset Threshold Hysteresis

MAX82_T/S/R/Z/Y 5

mV

Reset Threshold Temperature
Coefficient

40

ppm/°C

Reset Timeout Period t

RP

ms

VCC to RESET Delay V

RST

- VCC = 100mV 20 µs

MAX82_L/M, VCC = V

RST

max,

I

SOURCE

= 120µA

V

CC -

1.5

V

OH

MAX82_T/S/R/Z/Y, VCC = V

RST

max,

I

SOURCE

= 30µA

MAX82_L/M, VCC = V

RST

min,

I

SINK

= 3.2mA

0.4

MAX82_T/S/R/Z/Y VCC = V

RST

min,

I

SINK

= 1.2mA

0.3

TA = 0°C to +70°C, VCC = 1V,
V

CC

falling, I

SINK

= 50µA

0.3

RESET Output Voltage

V

OL

TA = T

MIN

to T

MAX

, VCC = 1.2V,

V

CC

falling, V

BATT

= 0V, I

SINK

= 100µA

V

MAX82_L/M, RESET = 0V, VCC = 5.5V

RESET Output Short-Circuit
Current (Note 2)

MAX82_T/S/R/Z/Y, RESET = 0V, VCC = 3.6V

µA

V

OH

VCC > 1.8V, I

SOURCE

= 150µA

MAX824L/M, MAX825L/M,
V

CC

= V

RST

max, I

SINK

= 3.2mA

0.4

RESET Output Voltage

V

OL

MAX824T/S/R/Z/Y, MAX825T/S/R/Z/Y,
V

CC

= V

RST

max, I

SINK

= 1.2mA

0.3

V

WATCHDOG INPUT (MAX823/MAX824)

Watchdog Timeout Period t

WD

s

WDI Pulse Width t

WDI

VIL = 0.4V, VIH = 0.8 ✕ V

CC

50 ns

V

IL

WDI Input Voltage (Note 3)

V

IH

0.7 ✕ V

CC

V

WDI = VCC, time average

WDI Input Current (Note 4)

WDI = 0, time average -20

µA

ELECTRICAL CHARACTERISTICS (continued)

(VCC= +4.75V to +5.5V for MAX82_L, VCC= +4.5V to +5.5V for MAX82_M, VCC= +3.15V to +3.6V for MAX82_T, VCC= +3V
to +3.6V for MAX82_S, VCC= +2.7V to +3.6V for MAX82_R, VCC= +2.38V to +2.75V for MAX82_Z, VCC= +2.25V to +2.75V for
MAX82_Y, T

A

= T

MIN

to T

MAX

, TA= -40°C to +85°C (SC70), TA= -40°C to +125°C (SOT23), unless otherwise noted. Typical values

are at T

A

= +25°C.) (Note 1)

SYMBOL

MIN TYP MAX

140 200 280

0.8 ✕ V

I

SOURCE

0.8 ✕ V

1.12 1.60 2.40

0.3 ✕ V

CC

CC

120 160

-15

800

400

CC