Maxim MAX808NESA, MAX808NEPA, MAX808NCPA, MAX808NCSA, MAX808MMJA Datasheet

19-1086; Rev 0; 6/96

8-Pin µP Supervisory Circuits

with ±1.5% Reset Accuracy

_______________General Description

The MAX801/MAX808 microprocessor (µP) supervisory
circuits monitor and control the activities of +5V µPs by
providing backup-battery switchover, low-line indica­tion, and µP reset. Additional features include a watch­dog for the MAX801 and CMOS RAM write protection
for the MAX808.

The MAX801/MAX808 offer a choice of reset-threshold
voltage (denoted by suffix letter): 4.675V (L), 4.575V
(N), and 4.425V (M). These devices are available in
8-pin DIP and SO packages.

________________________Applications

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

Pin Configurations appear at end of data sheet.

__________Typical Operating Circuit

+5V

0.1µF

0.1µF

BATT

V

CC

MAX808

OUT

LOWLINE

RESET

CE IN

CE OUT

GND

0.1µF

POWER FOR
CMOS RAM

NMI

RESET

µP SYSTEM

FROM I/O SYSTEM OR
ADDRESS DECODER

TO CMOS RAM

µP

POWER

____________________________Features

♦ Precision Voltage Monitoring, ±1.5% Reset

Accuracy

♦ 200ms Power-OK/Reset Time Delay
♦ RESET Output (MAX808)

RESET and RESET Outputs (MAX801)

♦ Watchdog Timer (MAX801)
♦ On-Board Gating of Chip-Enable Signals (MAX808):

Memory Write-Cycle Completion
3ns CE Gate Propagation Delay

♦ 1µA Standby Current
♦ Power Switching:

250mA in VCCMode
20mA in Battery-Backup Mode

♦ MaxCap™/SuperCap™ Compatible
♦ RESET Guaranteed Valid to VCC= 1V
♦ Low-Line Threshold 52mV Above Reset

Threshold

MaxCap is a trademark of The Carborundum Corp.
SuperCap is a trademark of Baknor Industries.

______________Ordering Information

PART*

MAX801_CPA

MAX801_CSA
MAX801_EPA -40°C to +85°C
MAX801_ESA
MAX801_MJA
MAX808_CPA
MAX808_CSA 0°C to +70°C 8 SO
MAX808_EPA
MAX808_ESA
MAX808_MJA -55°C to +125°C

* These parts offer a choice of reset threshold voltage. From the

table below, select the suffix corresponding to the desired
threshold and insert it into the blank to complete the part number.

**Contact factory for availability and processing to MIL-STD-883.

SUFFIX

L 4.60 4.675
N 4.50

M 4.35

TEMP. RANGE PIN-PACKAGE

0°C to +70°C
0°C to +70°C

-40°C to +85°C 8 SO

-55°C to +125°C
0°C to +70°C

-40°C to +85°C 8 Plastic DIP

-40°C to +85°C

RESET THRESHOLD (V)

MIN MAX

8 Plastic DIP
8 SO
8 Plastic DIP

8 CERDIP**
8 Plastic DIP

8 SO
8 CERDIP**

TYP

4.75

4.575 4.65

4.425 4.50

MAX801L/M/N, MAX808L/M/N

________________________________________________________________

Maxim Integrated Products

1

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]

8-Pin µP Supervisory Circuits
with ±1.5% Reset Accuracy

ABSOLUTE MAXIMUM RATINGS

Input Voltage (with respect to GND)

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

V

CC

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

V

BATT

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

Input Current

Peak ..........................................................................1.0A

V

CC

Continuous ............................................................500mA

V

CC

Peak.....................................................................250mA

I

BATT

Continuous ............................................................50mA

I

BATT

GND................................................................................50mA

OUT

+ 0.3V)

All Other Inputs...............................................................50mA

Output Current

OUT Peak..........................................................................1.0A

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

(VCC= 4.6V to 5.5V for the MAX80_L, VCC= 4.5V to 5.5V for the MAX80_N, VCC= 4.35V to 5.5V for the MAX80_M; V
T

= T

to T

A

MIN

Operating Voltage Range

, BATT (Note 1)

V

CC

V

in Normal Operating

OUT

Mode

MAX801L/M/N, MAX808L/M/N

VCCto OUT
On-Resistance

V

in Battery-Backup

OUT

Mode

BATT to OUT
On-Resistance

Supply Current in Normal
Operating Mode
(excludes I

Supply Current in Battery­Backup Mode (excludes
I

) (Note 2)

OUT

BATT Standby Current
(Note 3)

Battery-Switchover
Threshold

Battery-Switchover
Hysteresis

. Typical values are at VCC= 5V and TA= +25°C, unless otherwise noted.)

MAX

CONDITIONS

I

= 25mA VCC- 0.02

OUT

I

VCC= 4.5V VCC- 0.38 VCC- 0.25

VCC= 3V, V
VCC= 4.5V,

I

= 250mA

OUT

VCC= 3V, I

VCC= 0V V

VCC= 0V Ω

= 250mA, MAX80_C/E

OUT

I

= 250mA, MAX80_M VCC- 0.45

OUT

= 2.8V, I

BATT

MAX80_C/E
MAX80_M

= 100mA

OUT

V

BATT

V

BATT

V

BATT

V

BATT

V

BATT

V

BATT

MAX801

OUT

)

MAX808

VCC= 0V,
V

= 2.8V

BATT

V

+ 0.2V

BATT

≤ V

CC

V

= 2.8V

BATT

TA= +25°C
TA= T

MIN

to T

MAX

TA= +25°C
TA= T

MIN

Power-up
Power-down

OUT Continuous............................................................500mA

All Other Outputs ............................................................50mA

Continuous Power Dissipation (T

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

= +70°C)

A

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

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

Operating Temperature Ranges

MAX801_C_A/MAX808_C_A...............................0°C to +70°C

MAX801_E_A/MAX808_E_A ............................-40°C to +85°C

MAX801_MJA/MAX808_MJA.........................-55°C to +125°C

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

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

OUT

= 100mA

VCC- 0.25 VCC- 0.12

1.0 1.5

1.2 2.5
= 4.5V, I
= 2.8V, I
= 2.0V, I
= 4.5V, I
= 2.8V, I
= 2.0V, I

= 20mA V

OUT

= 10mA V

OUT

= 5mA

OUT

= 20mA 8

OUT

= 10mA 12 25

OUT

= 5mA

OUT

V

BATT
BATT

- 0.25 V

- 0.20 V

- 0.16

BATT

- 0.12

BATT

- 0.08

BATT

16 40
68 110

48 90

0.4 1

MAX80_C/E
MAX80_M

-0.1 0.1

to T

MAX

-1.0 1.0
V

+ 0.05

BATT

V

BATT

50 mV

BATT

1.8

5

50

= 2.8V;

UNITSMIN TYP MAXSYMBOLPARAMETER

V0 X 5.5

V

Ω

µA

µA

µA

V

2 _______________________________________________________________________________________

8-Pin µP Supervisory Circuits

with ±1.5% Reset Accuracy

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 4.6V to 5.5V for the MAX80_L, VCC= 4.5V to 5.5V for the MAX80_N, VCC= 4.35V to 5.5V for the MAX80_M; V
T

= T

to T

A

MIN

RESET AND LOW-LINE

Reset Threshold

LOWLINE to RESET
Threshold Voltage

LOWLINE Threshold,

Rising

V

CC

VCCto RESET Delay
VCCto LOWLINE Delay

RESET Active Timeout
Period

RESET Output Voltage

RESET Output

Short-Circuit Current
RESET Output Voltage

(MAX801)
RESET Output Short-

Circuit Current (MAX801)

LOWLINE Output Voltage

LOWLINE Output

Short-Circuit Current

WATCHDOG TIMER (MAX801)

Watchdog Timeout Period
Minimum Watchdog Input

Pulse Width
WDI Threshold Voltage

(Note 4)

WDI Input Current

. Typical values are at VCC= 5V and TA= +25°C, unless otherwise noted.)

MAX

CONDITIONS

VCCrising

V

RST

and falling

VCCfalling

LR

MAX80_L
MAX80_N

V

LL

MAX80_M
VCCfalling at 1mV/µs

RD

VCCfalling at 1mV/µs

LL

VCCrising

RP

I

SINK

V

BATT

VCCfalling
I

SINK

I

SOURCE

Output sink current, VCC= 4.25V

I

SC

Output source current
I

SINK

I

SOURCE

Output sink current

I

SC

Output source current, VCC= 4.25V
I

SINK

I

SOURCE

Output sink current, VCC= 4.25V

I

SC

Output source current

t

WD

VIL= 0.8V, VIH= 0.75V x V

V

IH

V

IL

RESET deasserted, WDI = 0V
RESET deasserted, WDI = V

MAX80_L
MAX80_N 4.500 4.575 4.650
MAX80_M

= 50µA,

= 3.2mA, VCC= 4.25V

= 3.2mA

= 3.2mA, VCC= 4.25V

VCC= 1.0V, MAX80_C

= 0V,

VCC= 1.2V, MAX80_E/M

= 0.1mA VCC- 1.5 VCC- 0.1

= 5mA, VCC= 4.25V

= 5mA, VCC= 4.25V

CC

CC

4.600 4.675 4.750

4.350 4.425 4.500

4.73 4.81

4.63 4.71

4.48 4.56

0.3

0.3

0.1 0.4

40

1.6

0.4

VCC- 1.5

55
15

0.4

VCC- 1.5

40
20

1.12 1.6 2.24 sec
100 ns

0.75 x V

CC

0.8

-50 -10
16 50

BATT

MAX801L/M/N, MAX808L/M/N

= 2.8V;

UNITSMIN TYP MAXSYMBOLPARAMETER

V

mV13Reset-Threshold Hysteresis
mV30 52 70V

V

µs17t
µs17t

ms140 200 280t

V

mA

V

mA

V

mA

V

µA

_______________________________________________________________________________________ 3

8-Pin µP Supervisory Circuits
with ±1.5% Reset Accuracy

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 4.6V to 5.5V for the MAX80_L, VCC= 4.5V to 5.5V for the MAX80_N, VCC= 4.35V to 5.5V for the MAX80_M; V
T

= T

to T

A

MIN

CHIP-ENABLE GATING (MAX808)CHIP-ENABLE GATING (MAX808)

CE IN Leakage Current
CE IN to CE OUT

Resistance (Note 5)
CE OUT Short-Circuit

Current (RESET Active)
CE IN to CE OUT

Propagation Delay (Note 6)
CE OUT Output Voltage

High (RESET Active)
RESET to CE OUT Delay

(Note 7)

. Typical values are at VCC= 5V and TA= +25°C, unless otherwise noted.)

MAX

CONDITIONS

V

= 4.25V ±0.00002 ±1 µA

CC

Enabled mode, VCC= V

(max) Ω75 150

RST

VCC= 4.25V, CE OUT = 0V

VCC= 5V, C
50Ω source-impedance driver

VCC= 4.25V, I
VCC= 0V, I

= 50pF,

LOAD

= 2mA

OUT

= 10µA V

OUT

VCCfalling, CE IN = 0V

3.5

BATT

- 0.1 V

BATT

BATT

= 2.8V;

UNITSMIN TYP MAXSYMBOLPARAMETER

mA15

ns38

V

µs18

Note 1: Either VCCor V
Note 2: The supply current drawn by the MAX80_ from the battery (excluding I

< V

V

CC

BATT

Characteristics

can go to 0V if the other is greater than 2V.

BATT

. In most applications, this is a brief period as VCCfalls through this region (see

) typically goes to 15µA when (V

OUT

).

Typical Operating

BATT

- 0.1V) <

Note 3: “+” = battery-discharging current, “-” = battery-charging current.
Note 4: WDI is internally connected to a voltage divider between V

MAX801L/M/N, MAX808L/M/N

disabling the watchdog function.

Note 5: The chip-enable resistance is tested with V
Note 6: The chip-enable propagation delay is measured from the 50% point at CE IN to the 50% point at CE OUT.

CE IN

= V

and GND. If unconnected, WDI is typically driven to 1.8V,

CC

CC

/ 2 and I

CE IN

= 1mA.

Note 7: If CE IN goes high, CE OUT goes high immediately and stays high until reset is deasserted and CE IN is low.

__________________________________________Typical Operating Characteristics

(VCC= 5V, V

VCC SUPPLY CURRENT vs. TEMPERATURE

75

70
65

60

55

SUPPLY CURRENT (µA)

50

CC

V

45

40

-55

= 2.8V, no load, TA= +25°C, unless otherwise noted.)

BATT

(NORMAL OPERATING MODE)

MAX801

MAX808

-15

-35 45 1255
TEMPERATURE (°C)

65

25

MAX801/808-01

105

85

TEMPERATURE (BATTERY-BACKUP MODE)

3.0

2.5

2.0

1.5

1.0

0.5

BATTERY SUPPLY CURRENT (µA)

0

-60 -20 60 140

BATTERY SUPPLY CURRENT vs.

20 100-40 40 120080

TEMPERATURE (°C)

CHIP-ENABLE PROPAGATION DELAY

MAX808

vs. TEMPERATURE

6

MAX801/808-02

5

4

3

2

PROPAGATION DELAY (ns)

1

0

-60 -20 60 140

20 100-40 40 120080

TEMPERATURE (°C)

MAX801/808-03

4 _______________________________________________________________________________________