NSC LM3705XBBPX-463, LM3705XBBPX-232, LM3705XBBP-232, LM3705XDMMX-463, LM3705XDMM-232 Datasheet

July 2002

LM3704/LM3705

Microprocessor Supervisory Circuits with Power Fail Input, Low Line Output and Manual Reset

General Description

The LM3704/LM3705 series of microprocessor supervisory circuits provide the maximum flexibility for monitoring power supplies and battery controlled functions in systems without backup batteries. The LM3704/LM3705 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 VCC 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 VCC.

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.

Features

nStandard Reset Threshold voltage: 3.08V

nCustom Reset Threshold voltages: For other voltages between 2.2V and 5.0V in 10mV increments, contact National Semiconductor Corp.

nNo external components required

nManual-Reset input

nRESET (LM3704) or RESET (LM3705) outputs

nPrecision supply voltage monitor

nFactory programmable Reset Timeout Delay

nSeparate Power Fail comparator

nAvailable in micro SMD package for minimum footprint

n±0.5% Reset threshold accuracy at room temperature

n±2% Reset threshold accuracy over temperature extremes

nReset assertion down to 1V VCC (RESET option only)

n28 µA VCC supply current

Applications

nEmbedded Controllers and Processors

nIntelligent Instruments

nAutomotive Systems

nCritical µP Power Monitoring

Typical Application

10136903

and Output Line Low Input, Fail Power with Circuits Supervisory Microprocessor LM3704/LM3705

Reset Manual

© 2002 National Semiconductor Corporation

DS101369

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LM3704/LM3705

Connection Diagram

	Top View
	(looking from the coating side)
	micro SMD 9 Bump Package
MSOP-10	BPA09

10136902

10136901

Pin Description

Pin No.

Name

Function

micro

MSOP

SMD

A1

2

Manual-Reset input. When

is less than VMRT (Manual Reset Threshold)

MR

MR

RESET/RESET is engaged.

B1

1

VCC

Power Supply input.

C1

10

Reset Logic Output. Pulses low for tRP (Reset Timeout Period) when triggered, and stays

RESET

low whenever VCC is below the reset threshold or when

MR

is below VMRT. It remains low

for tRP after either VCC rises above the reset threshold, or after

MR

input rises above

VMRT (LM3704 only).

RESET

Reset Logic Output. RESET is the inverse of

RESET

(LM3705 only).

C2

8

Power-Fail Logic Output. When PFI is below VPFT,

goes low; otherwise,

PFO

PFO

PFO

remains high.

C3

7

Low-Line Logic Output. Early Power-Fail warning output. Low when VCC falls below VLLOT

LLO

(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, 6

NC

No Connect.

A2

3

PFI

Power-Fail Comparator Input. When PFI is less than VPFT (Power-Fail Reset Threshold),

the

PFO

goes low; otherwise,

PFO

remains high.

B2

9

NC

No Connect. Test input used at factory only. Leave floating.

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Block Diagram

LM3704/LM3705

10136926

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LM3704/LM3705

Ordering Information

10136904

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

LM3704/LM3705

		Reset Timeout		Package		Package
Part Number	Output
					micro
		Period	MSOP			Marking
					SMD
LM3704XCBP-308	totem-pole	200ms			x	%%I4
LM3704XCBPX-308	totem-pole	200ms			x	%%I4
LM3704XCMM-308	totem-pole	200ms	x			R35B
LM3704XCMMX-308	totem-pole	200ms	x			R35B
LM3705XCBP-308	totem-pole	200ms			x	%%I5
LM3705XCBPX-308	totem-pole	200ms			x	%%I5
LM3705XCMM-308	totem-pole	200ms	x			R36B
LM3705XCMMX-308	totem-pole	200ms	x			R36B

%% is the datecode and will vary with time.

Table Of Functions

Part	Active	Active	Output	Reset	Manual	Power Fail	Low
Number	Low	High	(X = totem-pole)	Timeout	Reset	Comparator	Line
	Reset	Reset	(Y = open-drain)	Period			Output
LM3704	x		X, Y*	Customized	x	x	x
LM3705		x	X	Customized	x	x	x
* = available upon request. Contact National

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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 (VCC)	−0.3V to 6.0V
All Other Inputs	−0.3V to VCC + 0.3V
ESD Ratings (Note 2)
Human Body Model	1.5kV
Machine Model	150V

Power Dissipation (Note 3)

Operating Ratings (Note 1)

Temperature Range −40˚C ≤ TJ ≤ 85˚C

LM3704/LM3705 Series Electrical Characteristics

Limits in the standard typeface are for TJ = 25˚C and limits in boldface type apply over full operating range. Unless otherwise specified: VCC = +2.2V to 5.5V.

	Symbol			Parameter		Conditions	Min	Typ	Max	Units
	POWER SUPPLY
	VCC			Operating Voltage		LM3704	1.0		5.5	V
				Range: VCC		LM3705	1.2		5.5
	ICC			VCC Supply		All inputs = VCC; all outputs floating		28	50	µA
				Current
	RESET THRESHOLD
	VRST			Reset Threshold		VCC falling	−0.5		+0.5
							−2	VRST	+2	%
						VCC falling: TA = 0˚C to 70˚C	−1.5		+1.5
	VRSTH			Reset Threshold				0.0032•VRST		mV
				Hysteresis
	tRP			Reset Timeout		Reset Timeout Period = A	1	1.4	2
				Period		Reset Timeout Period = B	20	28	40	ms
						Reset Timeout Period = C	140	200	280
						Reset Timeout Period = D	1120	1600	2240
	tRD			VCC to Reset		VCC falling at 1mV/µs		20		µs
				Delay
	RESET (LM3705)
	VOL			RESET		VCC > 2.25V, ISINK = 900µA			0.3
						VCC > 2.7V, ISINK = 1.2mA			0.3	V
						VCC > 4.5V, ISINK = 3.2mA			0.4
	VOH			RESET		VCC > 1.2V, ISOURCE = 50µA	0.8 VCC
						VCC > 1.8V, ISOURCE = 150µA	0.8 VCC
						VCC > 2.25V, ISOURCE = 300µA	0.8 VCC			V
						VCC > 2.7V, ISOURCE = 500µA	0.8 VCC
						VCC > 4.5V, ISOURCE = 800µA	VCC − 1.5V
	ILKG			Output Leakage		VRESET = 5.5V			1.0	µA
				Current
		(LM3704)
	RESET
	VOL			RESET		VCC > 1.0V, ISINK = 50µA			0.3
						VCC > 1.2V, ISINK = 100µA			0.3
						VCC > 2.25V, ISINK = 900µA			0.3
						VCC > 2.7V, ISINK = 1.2mA			0.3	V
						VCC > 4.5V, ISINK = 3.2mA			0.4
	VOH					VCC > 2.25V, ISOURCE = 300µA	0.8 VCC
				RESET
						VCC > 2.7V, ISOURCE = 500µA	0.8 VCC
						VCC > 4.5V, ISOURCE = 800µA	VCC − 1.5V

LM3704/LM3705

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LM3704/LM3705

LM3704/LM3705 Series Electrical Characteristics (Continued)

Limits in the standard typeface are for TJ = 25˚C and limits in boldface type apply over full operating range. Unless otherwise specified: VCC = +2.2V to 5.5V.

Symbol

Parameter

Conditions

Min

Typ

Max

Units

PFI/MR

VPFT

PFI Input

1.200

1.225

1.250

V

Threshold

VMRT

Input

Low

0.8

MR

MR,

V

Threshold

2.0

MR, High

VPFTH/

0.0032•VRST

PFI/MR

Threshold

PFI/MR falling: VCC = VRST MAX to 5.5V

mV

VMRTH

Hysteresis

IPFI

Input Current (PFI

−75

75

nA

only)

RMR

35

56

75

kΩ

MR

Pull-up

Resistance

tMD

12

µS

MR

to Reset

Delay

tMR

25

µS

MR

Pulse Width

PFO,

LLO

VOL

PFO,

LLO

Output

VCC > 2.25V, ISINK = 900µA

0.3

Voltage

VCC > 2.7V, ISINK = 1.2mA

0.3

VCC > 4.5V, ISINK = 3.2mA

0.4

V

VOH

VCC > 2.25V, ISOURCE = 300µA

0.8 VCC

VCC > 2.7V, ISOURCE = 500µA

0.8 VCC

VCC > 4.5V, ISOURCE = 800µA

VCC − 1.5V

OUTPUT

LLO

VLLOT

LLO

Output

1.01•VRST

1.02•VRST

1.03•VRST

V

Threshold

(V

− VRST, VCC

LLO

falling)

VLLOTH

Low-Line

0.0032•VRST

mV

Comparator

Hysteresis

tCD

Low-Line

VCC falling at 1mV/µs

20

µs

Comparator Delay

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed conditions.

Note 2: The Human Body model is a 100 pF capacitor discharged through a 1.5 kΩ resistor into each pin. The machine model is a 200pF capacitor discharged directly into each pin.

Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, θJ-A, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperture is calculated using:

Where the value of θJ-A for the MSOP-10 package is 195˚C/W in a typical PC board mounting and the micro SMD package is 220˚C/W.

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