Maxim MAX6314US26D3-T, MAX6314US31D2-T, MAX6314US38D1-T Schematic [ru]

19-1090; Rev 2; 12/05

68HC11/Bidirectional-Compatible

µP Reset Circuit

General Description

The MAX6314 low-power CMOS microprocessor (µP)
supervisory circuit is designed to monitor power
supplies in µP and digital systems. The MAX6314’s
RESET output is bidirectional, allowing it to be directly
connected to µPs with bidirectional reset inputs, such
as the 68HC11. It provides excellent circuit reliability
and low cost by eliminating external components and
adjustments. The MAX6314 also provides a debounced
manual reset input.

This device performs a single function: it asserts a reset
signal whenever the V

supply voltage falls below a

CC

preset threshold or whenever manual reset is asserted.
Reset remains asserted for an internally programmed
interval (reset timeout period) after V

has risen above

CC

the reset threshold or manual reset is deasserted.
The MAX6314 comes with factory-trimmed reset

threshold voltages in 100mV increments from 2.5V
to 5V. Preset timeout periods of 1ms, 20ms, 140ms,
and 1120ms (minimum) are also available. The device
comes in a SOT143 package.

For a µP supervisor with an open-drain reset pin, see
the MAX6315 data sheet.

________________________Applications

Computers

Controllers

Intelligent Instruments

Critical µP and µC Power Monitoring

Portable/Battery-Powered Equipment

Typical Operating Circuit

Features

♦ Small SOT143 Package
♦ RESET Output Simplifies Interface to

Bidirectional Reset I/Os

♦ Precision Factory-Set V

Reset Thresholds:

CC

100mV Increments from 2.5V to 5V

♦ ±1.8% Reset Threshold Accuracy at TA= +25°C
♦ ±2.5% Reset Threshold Accuracy Over Temp.
♦ Four Reset Timeout Periods Available:

1ms, 20ms, 140ms, or 1120ms (minimum)

♦ Immune to Short V

Transients

CC

♦ 5µA Supply Current
♦ Pin-Compatible with MAX811

Ordering Information

(V)

MIN t

(ms)

RP

†

PART

MAX6314US50D1-T 5.00 1 AA_ _

MAX6314US49D1-T 4.90 1 AB_ _

MAX6314US48D1-T 4.80 1 AC_ _

MAX6314US47D1-T 4.70 1 AD_ _

MAX6314US46D1-T 4.63 1 AE_ _

MAX6314US45D1-T 4.50 1 AF_ _

†

The MAX6314 is available in a SOT143 package, -40°C to

+85°C temperature range.

††

The first two letters in the package top mark identify the part,

while the remaining two letters are the lot tracking code.

Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.

NOMINAL

V

TH

TOP

MARK

MAX6314

††

V

CC

V

CC

LASER­TRIMMED
RESISTORS

V

CC

4.7kΩ

RESET

CIRCUITRY

MR

MAX6314

**OR OTHER µC/µP WITH BIDIRECTIONAL RESET I/O PIN.

GND

________________________________________________________________ Maxim Integrated Products 1

RESET

68HC11**

RESET

µP

Ordering Information continued at end of data sheet.

Pin Configuration

TOP VIEW

*P

GND

1

MAX6314

2

SOT143

4

V

CC

MRRESET

3

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.

V

MAX6314

68HC11/Bidirectional-Compatible
µP Reset Circuit

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +2.5V to +5.5V, TA= -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.)

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.

Note 1: The MAX6314 monitors VCCthrough an internal, factory-trimmed voltage divider that programs the nominal reset threshold.

Factory-trimmed reset thresholds are available in 100mV increments from 2.5V to 5V (see Ordering and Marking Information).

Note 2: This is the minimum time RESET must be held low by an external pull-down source to set the active pull-up flip-flop.
Note 3: Measured from RESET V

OL

to (0.8 x VCC), R

LOAD

= ∞.

V

CC

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

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

CC

+ 0.3V)

Input Current (V

CC

).............................................................20mA

Output Current (RESET)......................................................20mA

Rate of Rise (V

CC

) ...........................................................100V/µs

Continuous Power Dissipation (T

A

= +70°C)

SOT143 (derate 4mW/°C above +70°C).......................320mW

Operating Temperature Range ...........................-40°C to +85°C

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

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

T

A

= +25°C

VCC= 5.5V, no load

TA= 0°C to +70°C

VTH> 4.0V

VCC= falling at 1mV/µs
MAX6314US_ _D1-T

VCC> 4.25V, I

SINK

= 3.2mA

CONDITIONS

V

0.4

V

OL

RESET Output Voltage

kΩ32 63 100

MR Pullup Resistance

VTH- 1.8% V

THVTH

+ 1.8%

V

TH

Reset Threshold (Note 1)

µA

512

I

CC

V1.0 5.5V

CC

Operating Voltage Range

VCCSupply Current

ns500

MR to Reset Delay

ns100

MR Glitch Rejection

µs1

MR Minimum Input Pulse

V

0.8V

IL

MR Input Threshold

ppm/°C60∆VTH/°CReset Threshold Tempco

µs35VCCto Reset Delay

ms

1 1.4 2

t

RP

Reset Timeout Period

UNITSMIN TYP MAXSYMBOLPARAMETER

V

IL

V

IH

V

IH

VCC= 3.6V, no load

TA= -40°C to +85°C

VTH< 4.0V

MAX6314US_ _D3-T

MAX6314US_ _D2-T

MAX6314US_ _D4-T

VCC> 1.2V, I

SINK

= 0.5mA

VCC> 2.5V, I

SINK

= 1.2mA

VCC> 1.0V, I

SINK

= 80µA

410

VTH- 2.5% VTH+ 2.5%

1120 1570 2240

140 200 280

20 28 40

0.3 x V

CC

2.4

0.7 x V

CC

0.3

0.3

0.3

V

ns400t

S

Transition Flip-Flop Setup Time (Note 2)

VCC= 5V

VCC= 5V

mA20

RESET Active Pullup Current

V0.4 0.9Active Pullup Enable Threshold

VCC= 3V

ns

333

kΩ4.2 4.7 5.2

RESET Pullup Resistance

333

666

VCC= 5V

666

t

R

RESET Output Rise Time
(Note 3)

C

LOAD

= 120pF

C

LOAD

= 250pF

C

LOAD

= 200pF

C

LOAD

= 400pF

MANUAL RESET INPUT

RESET INTERNAL PULLUP

MAX6314

68HC11/Bidirectional-Compatible

µP Reset Circuit

_______________________________________________________________________________________ 3

__________________________________________Typical Operating Characteristics

(TA = +25°C, unless otherwise noted.)

4.7kΩ PULL-UP
2V/div

MAX6314 PULL-UP
2V/div

INPUT
5V/div

200ns/div

PULLUP CHARACTERISTICS

MAX6314-01

100pF

4.7kΩ

+5V

74HC05

74HC05

V

CC

GND

MR

100pF

+5V

RESET

MAX6314

6

0

-50 -30 30 90

SUPPLY CURRENT vs. TEMPERATURE

2

1

5

MAX6314-02

TEMPERATURE (°C)

SUPPLY CURRENT (µA)

-10 10 50

3

4

70

VCC = 5V

VCC = 3V

VCC = 1V

6

0

0

1

35

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

2

1

5

MAX6314-03

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

2

3

4

4

TA = -40°C

TA = +25°C

TA = +85°C

50

0

-50 -30 10 90

POWER-DOWN RESET DELAY

vs. TEMPERATURE

10

40

MAX6314-04

TEMPERATURE (°C)

POWER-DOWN RESET DELAY (µs)

-10

20

30

30 50 70

VCC FALLING AT 1mV/µs

VTH = 4.63V

VTH = 3.00V

1.04

0.96

-50 -30 10 90

NORMALIZED RESET TIMEOUT PERIOD

vs. TEMPERATURE (V

CC

RISING)

0.97

0.98

1.02

1.00

1.03

MAX6314-05

TEMPERATURE (°C)

NORMALIZED RESET TIMEOUT PERIOD

-10

0.99

1.01

30 50 70

1.006

0.994

-50 -30 10 90

NORMALIZED RESET THRESHOLD

vs. TEMPERATURE (V

CC

FALLING)

0.996

0.998

1.004

1.000

MAX6314-06

TEMPERATURE (°C)

NORMALIZED RESET THRESHOLD

-10

1.002

30 50 70

100

0

10 100 1000

MAXIMUM TRANSIENT DURATION

vs. RESET COMPARATOR OVERDRIVE

20

MAX6314-07

RESET COMP. OVERDRIVE, VTH - VCC (mV)

MAXIMUM TRANSIENT DURATION (µs)

40

60

80

TA = +25°C
RESET OCCURS
ABOVE CURVE

VTH = 4.63V

VTH = 3.00V

600

0

-50 -30 10 90

RESET PULLUP TIME

vs. TEMPERATURE

100

200

500

300

MAX6314-08

TEMPERATURE (°C)

RESET PULL-UP-TIME (ns)

-10

400

30 50 70

CL = 390pF

CL = 100pF