MAXIM MAX705, MAX708, MAX813L User Manual

MAX705–MAX708/MAX813L

Low-Cost, µP Supervisory Circuits

________________________________________________________________

Maxim Integrated Products

1

_________________Pin Configurations

V

CC

PFI

MR

PFO

WDO

RESET

UNREGULATED DC

PUSHBUTTON

SWITCH

PFI

I/O LINE

INTERRUPT

µP

MAX705
MAX706

MAX813L

MAX667

+5V DC LINEAR

REGULATOR

V

CC

RESET

NMI

__________Typical Operating Circuit

19-4334; Rev. 8; 3/10

_______________General Description

The MAX705-MAX708/MAX813L microprocessor (µP)
supervisory circuits reduce the complexity and number
of components required to monitor power-supply and
battery functions in µP systems. These devices signifi­cantly improve system reliability and accuracy com­pared to separate ICs or discrete components.

The MAX705/MAX706/MAX813L provide four functions:

1) A reset output during power-up, power-down, and
brownout conditions.

2) An independent watchdog output that goes low if
the watchdog input has not been toggled within 1.6
seconds.

3) A 1.25V threshold detector for power-fail warning,
low-battery detection, or for monitoring a power sup­ply other than +5V.

4) An active-low manual-reset input.

The MAX707/MAX708 are the same as the MAX705/
MAX706, except an active-high reset is substituted for
the watchdog timer. The MAX813L is the same as the
MAX705, except RESET is provided instead of RESET.

Two supply-voltage monitor levels are available: The
MAX705/MAX707/MAX813L generate a reset pulse when
the supply voltage drops below 4.65V, while the
MAX706/MAX708 generate a reset pulse below 4.40V.
All four parts are available in 8-pin DIP, SO and µMAX

®

packages.

_______________________Applications

Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring

___________________________Features

o Available in Tiny µMAX Package
o Guaranteed RESET Valid at V

CC

= 1V

o Precision Supply-Voltage Monitor

4.65V in MAX705/MAX707/MAX813L

4.40V in MAX706/MAX708

o 200ms Reset Pulse Width
o Debounced TTL/CMOS-Compatible

Manual-Reset Input

o Independent Watchdog Timer—1.6s Timeout

(MAX705/MAX706)

o Active-High Reset Output

(MAX707/MAX708/MAX813L)

o Voltage Monitor for Power-Fail or Low-Battery

Warning

______________Ordering Information

PART TEMP RANGE PIN-PACKAGE

MAX705CPA

8 Plastic DIP

MAX705CSA 0°C to +70°C 8 SO

MAX705C/D 0°C to +70°C Dice*

Ordering Information continued at end of data sheet.

*

Dice are specified at TA= +25°C.

**

Contact factory for availability and processing to MIL-STD-883.
Devices in PDIP, SO and µMAX packages are available in both
leaded and lead-free packaging. Specify lead free by adding
the + symbol at the end of the part number when ordering.
Lead-free not available for CERDIP package.

0°C to +70°C

MAX705CUA 0°C to +70°C 8 µMAX

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.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

TOP VIEW

V

GND

MR

1

2

CC

MAX705

3

MAX706

MAX813L

PFI

4

WDO

8

RESET (RESET)

7

WDI

6

5

PFO

( ) ARE FOR MAX813L ONLY.
Pin Configurations continued at end of data sheet.

V

GND

DIP/SO

MR

1

2

CC

MAX707

3

PFI

MAX708

4

DIP/SO

RESET

8

RESET

7

N.C.

6

5

PFO

MAX705–MAX708/MAX813L

Low-Cost, µP Supervisory Circuits

2 _______________________________________________________________________________________

Terminal Voltage (with respect to GND)

V

CC

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

All Other Inputs (Note 1) ............... -0.3V to (V

CC

+ 0.3V)

Input Current

V

CC

...................................................... 20mA

GND .................................................... 20mA

Output Current (all outputs) ............................. 20mA

Continuous Power Dissipation (T

A

= +70°C)

Plastic DIP (derate 9.09mW/°C above +70°C) ....... 727mW

SO (derate 5.88mW/°C above +70°C) ............... 471mW

µMAX (derate 4.10mW/°C above +70°C) ............ 330mW

CERDIP (derate 8.00mW/°C above +70°C) .......... 640mW

Operating Temperature Ranges

MAX70_C__, MAX813LC__ .................... 0°C to +70°C

MAX70_E__, MAX813LE__ ................... -40°C to +85°C

MAX70_MJA ................................ -55°C to +125°C

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

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

Soldering Temperature (reflow)

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

Containing Lead(Pb)......................................................+240°C

ELECTRICAL CHARACTERISTICS

(VCC= 4.75V to 5.5V for MAX705/MAX707/MAX813L, VCC= 4.5V to 5.5V for MAX706/MAX708, TA= T

MIN

to T

MAX

, unless otherwise noted.)

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.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Operating Voltage Range V

CC

MAX70_C 1.0 5.5

V

MAX813LC 1.1 5.5
MAX70_E/M, MAX813LE/M 1.2 5.5

Reset Threshold (Note 2) V

RT

MAX705, MAX707, MAX813L 4.50 4.65 4.75
MAX706, MAX708 4.25 4.40 4.50

40 mV

Reset Pulse Width (Note 2) t

RS

140 200 280 ms

RESET Output Voltage

I

SOURCE

= 800µA VCC- 1.5

V

ABSOLUTE MAXIMUM RATINGS

Note 1: The input voltage limits on PFI and MR can be exceeded if the input current is less than 10mA.

Reset Threshold Hysteresis (Note 2)

I

SINK

= 3.2mA 0.4

0.3

0.3

RESET Output Voltage

MAX707, MAX708, I

SOURCE

= 800µA

V

MAX707, MAX708, I

SINK

= 1.2mA 0.4

0.8

0.9

MAX813L

VCC- 1.5

0.4

Watchdog Timeout Period t

WD

MAX705, MAX706, MAX813L

1.00 1.60 2.25 s

WDI Pulse Width t

WP

VIL= 0.4V, VIH= (VCC) (0.8) 50 ns

WDI Input Threshold

0.8
V

3.5

MAX70_C, VCC= 1V, I

SINK

= 50µA

MAX70_E/M, VCC= 1.2V, I

SINK

= 100µA

MAX813LC, I

SOURCE

= 4µA, VCC= 1.1V

MAX813LE/M, I

SOURCE

= 4µA, VCC= 1.2V

I

SOURCE

= 800µA

I

SINK

= 3.2mA

Low
High

WDI Input Current

MAX705, MAX706, MAX813L, WDI = V

CC

50 150

µA

MAX705, MAX706, MAX813L, WDI = 0V -150 -50

WDO Output Voltage

VCC- 1.5

V

0.4

MAX705, MAX706, MAX813L,
V

CC

= 5V

MAX705, MAX706, MAX813L,
I

SOURCE

= 800µA

MAX705, MAX706, MAX813L,
I

SINK

= 1.2mA

V

VCC- 1.5

MAX707C, MAX708C 50 350
MAX707E/M, MAX708E/M 50 500

Supply Current I

SUPPLY

MAX705C, MAX706C, MAX813LC 150 350

µA

MAX705E/M, MAX706E/M, MAX813LE/M 150 500

MAX705–MAX708/MAX813L

Low-Cost, µP Supervisory Circuits

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 4.75V to 5.5V for MAX705/MAX707/MAX813L, VCC= 4.5V to 5.5V for MAX706/MAX708, TA= T

MIN

to T

MAX

, unless otherwise noted.)

PARAMETER

SYMBOL CONDITIONS MIN TYP MAX UNITS

0.8
V

2.0

MR Pull-Up Current MR = 0V

100 250 600 µA

MR Pulse Width

t

MR

150 ns

Low

High

MR Input Threshold

MR to Reset Out Delay (Note 2)

t

MD

250 ns

PFI Input Threshold VCC= 5V 1.20 1.25 1.30 V

PFI Input Current -25.00 +0.01 +25.00 nA

PFO Output Voltage

I

SOURCE

= 800µA VCC- 1.5

V

I

SINK

= 3.2mA 0.4

Note 2: Applies to both RESET in the MAX705–MAX708 and RESET in the MAX707/MAX708/MAX813L.

MAX705–MAX708/MAX813L

Low-Cost, µP Supervisory Circuits

4 _______________________________________________________________________________________

__________________________________________Typical Operating Characteristics

MAX707/MAX708/MAX813L

RESET OUTPUT VOLTAGE

vs. SUPPLY VOLTAGE

500ms/div

V

CC

0V

RESET

0V

+5V

1V/div

+5V

1V/div

TA = +25°C

GND

RESET

V

CC

330pF

10k

Ω

MAX813L

RESET RESPONSE TIME

2µs/div

+5V

V

CC

0V

0V

+4V

+4V

GND

RESET

V

CC

330pF

10k

Ω

MAX705/MAX707

RESET OUTPUT VOLTAGE

vs. SUPPLY VOLTAGE

500ms/div

V

CC

0V

RESET

0V

+5V

1V/div

+5V

1V/div

V

CC

GND

RESET

V

CC

2k

Ω

RESET

330pF

TA = +25°C

MAX705/MAX707

RESET RESPONSE TIME

2µs/div

V

CC

+5V

RESET

+5V

+4V

1V/div

0V

TA = +25°C

V

CC

GND

RESET

V

CC

10k

Ω

RESET

30pF

POWER-FAIL COMPARATOR

DE-ASSERTION RESPONSE TIME

400ns/div

PFI

+1.20V

PFO

0V

+3V

+1.30V

VCC = +5V
T

A

= +25°C

+5V

PFO

30pF

1k

Ω

+1.25V

PFI

POWER-FAIL COMPARATOR

ASSERTION RESPONSE TIME

400ns/div

PFI

+1.30V

PFO

+5V

0V

+1.20V

1V/div 50mV/div

+5V

PFO

30pF

1k

Ω

+1.25V

PFI

VCC = +5V
T

A

= +25°C

MAX707

RESET, RESET ASSERTION

400ns/div

0V

+5V

RESET

RESET

1V/div

VCC = V

RT

TA = +25°C

+5V

0V

V

CC

GND

RESET

10k

Ω

330pF

RESET

10k

Ω

330pF

MAX707

RESET, RESET DE-ASSERTION

400ns/div

0V

+5V

RESET

RESET

2V/div

VCC = V

RT

TA = +25°C

+5V

0V

V

CC

GND

RESET

RESET

10k

Ω

330pF

10k

Ω

330pF