NSC LM3710YQMM-232, LM3710XQMM-308, LM3710XQBP-308, LM3710XNMM-470, LM3710XKMMX-463 Datasheet

LM3710/LM3711

Microprocessor Supervisory Circuits with Power Fail

Input, Low Line Output, Manual Reset and Watchdog

Timer

General Description

The LM3710/LM3711 series of microprocessor supervisory

circuits provide the maximum flexibility for monitoring power

supplies and battery controlled functions in systems without

backup batteries. The LM3710/LM3711 series are available

in MSOP-10 and 9-bump micro SMD packages.

Built-in features include the following:

Reset: Reset is asserted during power-up, power-down, and

brownout conditions. RESET is guaranteed down to V

CC

of

1.0V.

Manual Reset Input: An input that asserts reset when pulled

low.

Power-Fail Input: A 1.225V threshold detector for power fail

warning, or to monitor a power supply other than V

CC

.

Low Line Output: This early power failure warning indicator

goes low when the supply voltage drops to a value which is

2% higher than the reset threshold voltage.

Watchdog Timer: The WDI (Watchdog Input) monitors one of

the µP’s output lines for activity. If no output transition occurs

during the watchdog timeout period, reset is activated.

Features

n Standard Reset Threshold voltage: 3.08V

n Custom Reset Threshold voltages: For other voltages

between 2.2V and 5.0V in 10mV increments, contact

National Semiconductor Corp.

n No external components required

n Manual-Reset input

n RESET (LM3710) or RESET (LM3711) outputs

n Precision supply voltage monitor

n Factory programmable Reset and Watchdog Timeout

Delays

n Separate Power Fail comparator

n Available in micro SMD package for minimum footprint

n

±

0.5% Reset threshold accuracy at room temperature

n

±

2% Reset threshold accuracy over temperature

extremes

n Reset assertion down to 1V V

CC

(RESET option only)

n 28 µA V

CC

supply current

Applications

n Embedded Controllers and Processors

n Intelligent Instruments

n Automotive Systems

n Critical µP Power Monitoring

Typical Application

20011803

June 2002

LM3710/LM3711 Microprocessor Supervisory Circuits with Power Fail Input, Low Line Output,

Manual Reset and Watchdog Timer

© 2002 National Semiconductor Corporation DS200118 www.national.com

Connection Diagram

MSOP-10

Top View

(looking from the coating side)

micro SMD 9 Bump Package

BPA09

20011802

20011801

Pin Descriptions

Pin No.

Name Function

micro

SMD

MSOP

A1 2 MR

Manual-Reset input. When MR is less than V

MRT

(Manual Reset Threshold)

RESET/RESET is engaged.

B1 1 V

CC

Power Supply input.

C1 10 RESET

Reset Logic Output. Pulses low for t

RP

(Reset Timeout Period) when triggered, and stays

low whenever V

CC

is below the reset threshold or when MR is below V

MRT

. It remains low

for t

RP

after either V

CC

rises above the reset threshold, or after MR input rises above

V

MRT

(LM3710 only).

RESET Reset Logic Output. RESET is the inverse of RESET (LM3711 only).

C2 8 PFO Power-Fail Logic Output. When PFI is below V

PFT

, PFO goes low; otherwise, PFO

remains high.

C3 7 LLO

Low-Line Logic Output. Early Power-Fail warning output. Low when V

CC

falls below V

LLOT

(Low-Line Output Threshold). This output can be used to generate an NMI (Non-Maskable

Interrupt) to provide an early warning of imminent power-failure.

B3 5 GND Ground reference for all signals.

A3 4 WDI Watchdog Input Transition Monitor: If no transition activity occurs for a period exceeding

t

WD

(Watchdog Timeout Period), reset is engaged.

A2 3 PFI Power-Fail Comparator Input. When PFI is less than V

PFT

(Power-Fail Reset Threshold),

the PFO goes low; otherwise, PFO remains high.

B2 6, 9 NC No Connect. Test input used at factory only. Leave floating.

LM3710/LM3711

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Block Diagram

20011805

LM3710/LM3711

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Ordering Information

20011804

*

For other voltages between 2.2V and 5.0V, please contact National Semiconductor sales office.

LM3710/LM3711

Part Number Output

Reset Timeout

Period

Watchdog

Timeout

Period

Package

Package

Marking

MSOP

micro

SMD

LM3710XQBP-308 totem-pole 200ms 1600ms x %%IA

LM3710XQBPX-308 totem-pole 200ms 1600ms x %%IA

LM3710XQMM-308 totem-pole 200ms 1600ms x R37B

LM3710XQMMX-308 totem-pole 200ms 1600ms x R37B

LM3711XQBP-308 totem-pole 200ms 1600ms x %%IB

LM3711XQBPX-308 totem-pole 200ms 1600ms x %%IB

LM3711XQMM-308 totem-pole 200ms 1600ms x R38B

LM3711XQMMX-308 totem-pole 200ms 1600ms x R38B

%% is the datecode and will vary with time.

Table Of Functions

Part

Number

Active

Low

Reset

Active

High

Reset

Output

(X = totem-pole)

(Y = open-drain)

Reset

Timeout

Period

Watchdog

Timeout

Period

Manual

Reset

Power Fail

Comparator

Low

Line

Output

LM3710 x X, Y

*

Customized Customized x x x

LM3711 x X Customized Customized x x x

*

= available upon request. Contact National

LM3710/LM3711

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales Office/

Distributors for availability and specifications.

Supply Voltage (V

CC

) −0.3V to 6.0V

All Other Inputs −0.3V to V

CC

+ 0.3V

ESD Ratings (Note 2)

Human Body Model

Machine Model

1.5kV

150V

Power Dissipation (Note 3)

Operating Ratings (Note 1)

Temperature Range −40˚C ≤ T

J

≤ 85˚C

LM3710/LM3711 Series Electrical Characteristics

Limits in the standard typeface are for T

J

= 25˚C and limits in boldface type apply over full operating range. Unless otherwise

specified: V

CC

= +2.2V to 5.5V.

Symbol Parameter Conditions Min Typ Max Units

POWER SUPPLY

V

CC

Operating Voltage

Range: V

CC

LM3710 1.0 5.5

V

LM3711 1.2 5.5

I

CC

V

CC

Supply

Current

All inputs = V

CC

; all outputs floating 28 50 µA

RESET THRESHOLD

V

RST

Reset Threshold V

CC

falling −0.5

−2

V

RST

+0.5

+2

%

V

CC

falling: T

A

= 0˚C to 70˚C −1.5 +1.5

V

RSTH

Reset Threshold

Hysteresis

0.0032

•

V

RST

mV

t

RP

Reset Timeout

Period

Reset Timeout Period = E, J, N, S

Reset Timeout Period = F, K, P, T

Reset Timeout Period = G, L, Q, U

Reset Timeout Period = H, M, R, V

1

20

140

1120

1.4

28

200

1600

2

40

280

2240

ms

t

RD

V

CC

to Reset

Delay

V

CC

falling at 1mV/µs 20 µs

RESET (LM3711)

V

OL

RESET V

CC

>

2.25V, I

SINK

= 900µA 0.3

VV

CC

>

2.7V, I

SINK

= 1.2mA 0.3

V

CC

>

4.5V, I

SINK

= 3.2mA 0.4

V

OH

RESET V

CC

>

1.2V, I

SOURCE

= 50µA 0.8 V

CC

V

V

CC

>

1.8V, I

SOURCE

= 150µA 0.8 V

CC

V

CC

>

2.25V, I

SOURCE

= 300µA 0.8 V

CC

V

CC

>

2.7V, I

SOURCE

= 500µA 0.8 V

CC

V

CC

>

4.5V, I

SOURCE

= 800µA V

CC

− 1.5V

I

LKG

Output Leakage

Current

V

RESET

= 5.5V 1.0 µA

RESET (LM3710)

V

OL

RESET V

CC

>

1.0V, I

SINK

= 50µA 0.3

V

V

CC

>

1.2V, I

SINK

= 100µA 0.3

V

CC

>

2.25V, I

SINK

= 900µA 0.3

V

CC

>

2.7V, I

SINK

= 1.2mA 0.3

V

CC

>

4.5V, I

SINK

= 3.2mA 0.4

V

OH

RESET V

CC

>

2.25V, I

SOURCE

= 300µA 0.8 V

CC

V

CC

>

2.7V, I

SOURCE

= 500µA 0.8 V

CC

V

CC

>

4.5V, I

SOURCE

= 800µA V

CC

− 1.5V

LM3710/LM3711

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