Maxim MAX807LEWE, MAX807LMJE, MAX807LCPE, MAX807LCWE, MAX807NCWE Datasheet

19-0433; Rev 0; 9/95

Full-Featured µP Supervisory Circuit with

±1.5% Reset Accuracy

_______________General Description

The MAX807 microprocessor (µP) supervisory circuit
reduces the complexity and number of components
needed to monitor power-supply and battery-control func­tions in µP systems. A 70µA supply current makes the
MAX807 ideal for use in portable equipment, while a 2ns
chip-enable propagation delay and 250mA output current
capability (20mA in battery-backup mode) make it suit­able for larger, higher-performance equipment.

The MAX807 comes in 16-pin DIP and SO packages, and
provides the following functions:

1) µP reset. The active-low RESEToutput is asserted dur­ing power-up, power-down, and brownout conditions,
and is guaranteed to be in the correct state for V
down to 1V.

CC

2) Active-high RESET output.

3) Manual-reset input.

4) Two-stage power-fail warning. A separate low-line
comparator compares VCCto a threshold 52mV above
the reset threshold. This low-line comparator is more
accurate than those in previous µP supervisors.

5) Backup-battery switchover for CMOS RAM, real-time
clocks, µPs, or other low-power logic.

6) Write protection of CMOS RAM or EEPROM.

7) 2.275V threshold detector—provides for power-fail
warning and low-battery detection, or monitors a
power supply other than +5V.

8) BATT OK status flag indicates that the backup-battery
voltage is above 2.275V.

9) Watchdog-fault output—asserted if the watchdog input
has not been toggled within a preset timeout period.

________________________Applications

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

____________________________Features

♦ Precision 4.675V (MAX807L) or 4.425V

(MAX807M), or 4.575V (MAX807N) Voltage
Monitoring

♦ 200ms Power OK / Reset Time Delay
♦ RESET

and RESET Outputs

♦ Independent Watchdog Timer
♦ 1µA Standby Current
♦ Power Switching:

250mA in V

CC

Mode

20mA in Battery-Backup Mode

♦ On-Board Gating of Chip-Enable Signals:

2ns CE Gate Propagation Delay

♦ MaxCap™ and SuperCap™ Compatible
♦ Voltage Monitor for Power-Fail
♦ Backup-Battery Monitor
♦ Guaranteed RESET

Valid to VCC= 1V

♦ ±1.5% Low-line Threshold Accuracy 52mV above

Reset Threshold

__________________Pin Configuration

TOP VIEW

WDI
GND

LOW LINE

RESET

PFO
V

PFI

1
2

CC

3

MAX807

4
5

MR

6
7
8

16
15
14
13
12
11
10

9

OUT

BATT OK

BATT

BATT ON
CE IN
CE OUT
WDO
RESET

MAX807L/M/N

DIP/SO

Ordering Information and Typical Operating Circuit appear at end of data sheet.

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

________________________________________________________________

Maxim Integrated Products

Call toll free 1-800-998-8800 for free samples or literature.

1

Full-Featured µP Supervisory Circuit with
±1.5% Reset Accuracy

ABSOLUTE MAXIMUM RATINGS

Input Voltages (with respect to GND)

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

V

CC

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

V

BATT

All Other Inputs......................................-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

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

MAX807L/M/N

absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

(VCC= 4.60V to 5.5V for the MAX807L, VCC= 4.50V to 5.5V for the MAX807N, VCC= 4.35V to 5.5V for the MAX807M,
V

= 2.8V, V

BATT

Operating Voltage Range

, VCC(Note 1)

V

BATT

V

in Normal Operating

OUT

Mode

VCCto OUT On-Resistance

V

in Battery-Backup Mode V

OUT

BATT to OUT On-Resistance 12 25

Supply Current in Normal
Operating Mode (excludes I

Supply Current in Battery­Backup Mode (excludes I
(Note 2)

BATT Standby Current (Note 3)

Battery-Switchover Threshold
Battery-Switchover Hysteresis 50

BATT ON Output, Low Voltage V

= 0V, TA= T

PFI

OUT

OUT

)

MIN

to T

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

MAX

VCC= 4.5V

VCC= 3V, V

BATT

VCC= 4.5V,
I

= 250mA

OUT

VCC= 3V, I
V

BATT

V

BATT

V

BATT

V

BATT

V

BATT

V

BATT

OUT

= 4.5V, I
= 2.8V, I
= 2.0V, I
= 4.5V, I
= 2.8V, I
= 2.0V, I

)

VCC= 0V, V

V

BATT

V

BATT

RST (max)

BATT

+ 0.2V ≤ V

= 2.8V

, I

SINK

SOURCE

Continuous Power Dissipation (T

Plastic DIP (derate 10.53mW/°C above +70°C) ...........842mW

= +70°C)

A

Wide SO (derate 9.52mW/°C above +70°C).................762mW

CERDIP (derate 10.00mW/°C above +70°C)................800mW

Operating Temperature Ranges

MAX807_C_E.......................................................0°C to +70°C

MAX807_E_E ....................................................-40°C to +85°C

MAX807_MJE .................................................-55°C to +125°C

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

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

CONDITIONS

- 0.25 V

- 0.20 V

2 2.7BATT ON Output, High Voltage VCC= 0V, I

VCC- 0.02I

1.0 1.4

1.2 2.5

V

BATT
BATT
BATT

8.5

16 40

0.4 1

V

+ 0.05

BATT

V

BATT

0.1 0.4

1.8

- 0.17

- 0.12

- 0.08

5

50

= 25mA

OUT

I

= 250mA,

= 2.8V, I

OUT

MAX807C/E
I

OUT

MAX807M

= 100mA

OUT

= 250mA,

VCC- 0.35 VCC- 0.22

VCC- 0.45

VCC- 0.25 VCC- 0.12
MAX807C/E
MAX807M

= 100mA

= 20mA, VCC= 0V

OUT

= 10mA, VCC= 0V

OUT

= 5mA, VCC= 0V

OUT

= 20mA

OUT

= 10mA

OUT

= 5mA

OUT

V

BATT
BATT

TA= +25°C

= 2.8V

MAX807C/E
MAX807M

-0.1 0.1

to

-1.0 1.0

CC

TA= +25°C
TA= T

MIN

T

MAX

Power up
Power down

= 3.2mA V

= 0.1mA, V

= 2.8V V

BATT

UNITSMIN TYP MAXSYMBOLPARAMETER

V0 5.5

V

Ω

V

Ω

µA70 110

µA

µA

V

mV

2 _______________________________________________________________________________________

Full-Featured µP Supervisory Circuit with

±1.5% Reset Accuracy

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 4.60V to 5.5V for the MAX807L, VCC= 4.50V to 5.5V for the MAX807N, VCC= 4.35V to 5.5V for the MAX807M,
V

= 2.8V, V

BATT

BATT ON Output
Short-Circuit Current

RESET, LOW LINE, AND WATCHDOG TIMER

Reset Threshold VCCrising and falling

Reset Threshold Hysteresis
LOW LINE to RESET

Threshold Voltage
LOW LINE Threshold,

VCCRising

VCCto LOW LINE Delay VCCfalling at 1mV/µs 24 µs
RESET Active Timeout Period VCCrising
Watchdog Timeout Period
Minimum Watchdog Input

Pulse Width

RESET Output Voltage

RESET Output
Short-Circuit Current

RESET Output Voltage
RESET Output

Short-Circuit Current
LOW LINE Output Voltage
LOW LINE Output

Short-Circuit Current
WDO Output Voltage
WDO Output

Short-Circuit Current
WDI Threshold Voltage

(Note 4)
WDI Input Current

= 0V, TA= T

PFI

MIN

to T

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

MAX

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

Sink current 70
Source current, VCC= 0V, V

RST

V

VCCfalling 30 52 70 mV

LR

V

LL

RP

t

WD

VIL= 0.8V, VIH= 0.75 x V

I

= 50µA,

SINK

V

= 0V, VCCfalling

BATT

= 3.2mA, VCC= 4.25V

SINK

I

= 0.1mA

SOURCE

I

SC

Output source current

= 3.2mA

SINK

I

= 5mA

SOURCE

I

SC

Output source current, VCC= 4.25V

= 3.2mA, VCC= 4.25V

SINK

I

= 5mA

SOURCE

I

SC

Output source current

= 3.2mA

SINK

I

= 5mA

SOURCE

I

SC

Output source current

V

IH

V

IL

V

IH

Reset deasserted, WDI = V

BATT

MAX807L
MAX807N
MAX807M

CC

VCC= 1V,
MAX807_C

VCC= 1.2V,
MAX807_E/M

CC

= 2.8V

4.600 4.675 4.750

4.500 4.575 4.650V

4.350 4.425 4.500

1.12 1.6 2.24 sec
100 ns

VCC- 1.5 VCC- 0.1

VCC- 1.5

VCC- 1.5

VCC- 1.5

0.75 x V

-50 -10Reset deasserted, WDI = 0V

5

13 mV

4.73 4.81MAX807L

4.63 4.71MAX807N

4.48 4.56MAX807M

0.1 0.4I

60Output sink current, VCC= 4.25V

1.6

60Output sink current
15

28Output sink current, VCC= 4.25V
20

35Output sink current
20

CC

16 50

0.3

0.3

0.4I

0.4I

0.4I

0.8

mA

V

V

µs26VCCto RESET Delay VCCfalling at 1mV/µs

ms140 200 280t

V

mA

V

mA

V

mA

V

mA

V

µA

MAX807L/M/N

_______________________________________________________________________________________ 3

Full-Featured µP Supervisory Circuit with
±1.5% Reset Accuracy

ELECTRICAL CHARACTERISTICS (continued)

(VCC= 4.60V to 5.5V for the MAX807L, VCC= 4.50V to 5.5V for the MAX807N, VCC= 4.35V to 5.5V for the MAX807M,
V

= 2.8V, V

BATT

PFI Input Threshold V

PFI Leakage Current ±0.005 ±40 nA

CHIP-ENABLE GATING

MAX807L/M/N

CE IN to CE OUT Resistance
(Note 6)

CE OUT Short-Circuit Current
(RESET active)

CE IN to CE OUT
Propagation Delay (Note 7)

CE OUT Output Voltage High
(RESET active)

RESET to CE OUT Delay VCCfalling 28 µs

MANUAL RESET INPUT

MR Minimum Pulse Input 1 µs
MR-to-RESET Propagation

Delay
MR Threshold
MR Pull-Up Current MR = 0V 50 100 200 µA

BATT OK COMPARATOR

BATT OK Threshold V
BATT OK Hysteresis 20 mV

LOGIC OUTPUTS

Output Voltage
(PFO, BATT OK)

Output Short-Circuit Current I

Note 1: Either VCCor V
Note 2: The supply current drawn by the MAX807 from the battery (excluding I

< V

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

disabling the watchdog function.

Note 5: Overdrive (V
Note 6: The chip-enable resistance is tested with V
Note 7: The chip-enable propagation delay is measured from the 50% point at CE

CC

= 0V, TA= T

PFI

BATT

< V

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

BATT

) is measured from center of hysteresis band.

OD

to T

MIN

can go to 0V, if the other is greater than 2.0V.

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

MAX

CONDITIONS UNITSMIN TYP MAXSYMBOLPARAMETER

V

falling

PFI

PFT

V

rising

PFI

VOD= 30mV, V

Enabled mode, VCC= V
VCC= 5V, disabled mode,

CE OUT = 0V, MR = 0V
VCC= 5V, C

50Ω source impedance driver

Disabled mode, MR = 0V

V

IH

V

IL

BOK

V

OLISINK

V

OHISOURCE

SC

= 3.2mA 0.4

Output sink current 35
Output source current 20

CE IN

falling

PFI

RST

= 50pF,

LOAD

= 5mA VCC- 1.5

and GND. If unconnected, WDI is driven to 1.8V (typical),

CC

= VCC/2, and I

(max)

VCC= 5V,
I

OUT

VCC= 0V,
I

OUT

) typically goes to 15µA when (V

OUT

= 1mA.

CE IN

2.20 2.265 2.33

2.22 2.285 2.35

= 2mA

= 10µA

3.5

V

- 0.1 V

BATT

2.4

2.200 2.265 2.350 V

Typical Operating Characteristics

IN to the 50% point at CE OUT.

BATT

BATT

0.8

- 0.1V)

V

mV20PFI Hysteresis

µs14PFI to PFO Delay (Note 5)

µA±0.00002 ±1CE IN Leakage Current Disabled mode, MR = 0V

Ω75 150

mA17

ns28

V

ns170

V

V

mA

).

4 _______________________________________________________________________________________

Full-Featured µP Supervisory Circuit with

±1.5% Reset Accuracy

__________________________________________Typical Operating Characteristics

(VCC= 5V, V

VCC SUPPLY CURRENT vs. TEMPERATURE

80
78

76
74
72
70
68

SUPPLY CURRENT (µA)

66

CC

V

64
62
60

-60 -20 60 140

30

25

20

15

10

BATT-to-OUT ON-RESISTANCE (Ω)

5

-60 -20 60 140

4.70

4.65

4.60

4.55

4.50

RESET THRESHOLD (V)

4.45

4.40

-60 -20 60 140

= 2.8V, PFI = 0V, no load, TA= +25°C, unless otherwise noted.)

BATT

BATTERY SUPPLY CURRENT vs.

(NORMAL OPERATING MODE)

20 100-40 40 120080

TEMPERATURE (°C)

BATT-to-OUT ON-RESISTANCE

vs. TEMPERATURE

V

CC

I

OUT

V

BATT

V

BATT

V

BATT

20 100-40 40 120080

TEMPERATURE (°C)

RESET THRESHOLD
vs. TEMPERATURE

MAX807L

MAX807N

MAX807M

20 100-40 40 120080

TEMPERATURE (°C)

= 0V

= 10mA

= 2.0V

= 2.8V

= 4.5V

MAX807-01

MAX807-04

MAX807-07

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

1.6

1.5

1.4

1.3

1.2

1.1

1.0

-to-OUT ON-RESISTANCE (Ω)

0.9

CC

V

0.8

0.7

-60 -20 60 140

vs. TEMPERATURE (V

280
260

240

220

200

180

RESET TIMEOUT PERIOD (ms)

160
140

-60 -20 60 140

20 100-40 40 120080

TEMPERATURE (°C)

VCC-to-OUT ON-RESISTANCE

vs. TEMPERATURE

20 100-40 40 120080

TEMPERATURE (°C)

RESET TIMEOUT PERIOD

20 100-40 40 120080

TEMPERATURE (°C)

I

= 250mA

OUT

RISING)

CC

CHIP-ENABLE PROPAGATION DELAY

6

MAX807-02

5

4

3

2

PROPAGATION DELAY (ns)

1

0

2.340

MAX807-05

2.320

2.300

2.280

2.260

PFI THRESHOLD (V)

2.240

2.220

2.200

80

MAX807-08

70
60
50
40
30
20
10

LOW LINE-to-RESET THRESHOLD (mV)

0

vs. TEMPERATURE

-60 -20 60 140

vs. TEMPERATURE (V

-60 -20 60 140

vs. TEMPERATURE (V

-60 -20 60 140

20 100-40 40 120080

TEMPERATURE (°C)

PFI THRESHOLD

20 100-40 40 120080

TEMPERATURE (°C)

LOW LINE -to-RESET THRESHOLD

20 100-40 40 120080

TEMPERATURE (°C)

PFI

CC

FALLING)

FALLING)

MAX807L/M/N

MAX807-03

MAX807-06

MAX807-09

_______________________________________________________________________________________

5