DS1818R-5-U+ - Hytronics - Datasheet.Live

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FEATURES

§ Automatically restarts a microprocessor after

power failure

§ Monitors pushbutton for external override

§ Maintains reset for 150 ms after VCC returns

to an in-tolerance condition

§ Reduces need for discrete components

§ Precision temperature-compensated voltage

reference and voltage sensor

§ Accurate 5%, 10% or 20% power monitoring

§ Low-cost TO-92 or space saving surface

mount SOT-23 packages available

§ Efficient open-drain output with internal

5.5 kW pull-up resistor

§ Operating temperature -40°C to +85°C

PIN ASSIGNMENT

PIN DESCRIPTION

TO-92

1 RST Active Low Reset Output

2 VCC Power Supply

3 GND Ground

SOT-23

1 RST Active Low Reset Output

2 VCC Power Supply

3 GND Ground

DESCRIPTION

The DS1818 EconoReset uses a precision temperature-compensated reference and comparator circuit to

monitor the status of the power supply (VCC). When an out-of-tolerance condition is detected, an internal

power-fail signal is generated which forces reset to the active state. When VCC returns to an in-tolerance

condition, the reset signal is kept in the active state for approximately 150 ms to allow the power supply

and processor to stabilize.

The DS1818 also monitors a pushbutton on the reset output. If the reset line is pulled low, a reset is

generated upon release and the DS1818 output will be held in reset output low for typically 150 ms.

DS1818

3.3V EconoReset with Pushbutton

www.maxim-ic.com

TOP VIEW

SOT-23 PACKAGE

See Mech.

Drawings Section

On Website

1 2 3

BOTTOM VIEW

TO-92 PACKAGE

See Mech.

Drawings Section

On Website

DALLAS

DS1818

Econo

Reset

DS1818

2 of 5

OPERATION - POWER MONITOR

The DS1818 provides the functions of detecting out-of-tolerance power supply conditions and warning a

processor-based system of impending power failures. When VCC is detected as out-of-tolerance, the RST

signal is asserted. On power-up, RST is kept active for approximately 150 ms after the power supply has

reached the selected tolerance. This allows the power supply and microprocessor to stabilize before RST

is released.

BLOCK DIAGRAM (OPEN-DRAIN OUTPUT) Figure 1

APPLICATION EXAMPLE Figure 2

OPERATION - PUSHBUTTON RESET

The DS1818 provides a pushbutton switch for manual reset control. When the DS1818 is not in a reset

cycle, a pushbutton reset can be generated by pulling the RST pin low for at least 1 ms. When the

pushbutton is held low, the RST is forced active low and will remain active low for about 150 ms after

the pushbutton is released. See Figure 2 for an application example and Figure 3 for the timing diagram.

TIMING DIAGRAM: PUSHBUTTON RESET Figure 3

DS1818

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TIMING DIAGRAM: POWER-UP Figure 4

TIMING DIAGRAM: POWER-DOWN Figure 5

DS1818

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ABSOLUTE MAXIMUM RATINGS*

Voltage on VCC Pin Relative to Ground -0.5V to +7.0V

Voltage on RST Relative to Ground -0.5V to +5VCC +0.5V

Operating Temperature -40°C to +85°C

Storage Temperature -55°C to +125°C

Soldering Temperature 260°C for 10 seconds

* This is a stress rating only and functional operation of the device at these or any other conditions

above those indicated in the operation sections of this specification is not implied. Exposure to

absolute maximum rating conditions for extended periods of time may affect reliability.

RECOMMENDED DC OPERATING CONDITIONS (-40°C to +85°C)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Supply Voltage VCC 1.0 5.5 V 1

DC ELECTRICAL CHARACTERISTICS (-40°C to +85°C; VCC=1.2V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

Output Current @ 0.4 V IOL +10 mA 2, 3

Voltage Input Low VIL 0.4 V 1

Voltage Input High VIH 0.7

*VCC

Operating Current VCC < 5.5V ICC 28 35 mA4

VCC Trip Point (DS1818-5) VCCTP 2.98 3.06 3.15 V 1

VCC Trip Point (DS1818-10) VCCTP 2.80 2.88 2.97 V 1

VCC Trip Point (DS1818-20) VCCTP 2.47 2.55 2.64 V 1

Internal Pull-up Resistor RP3.50 5.5 7.5 kW7

Output Capacitance COUT 10 pF

AC ELECTRICAL CHARACTERISTICS (-40°C to +85°C; VCC=1.2V to 5.5V)

PARAMETER SYMBOL MIN TYP MAX UNITS NOTES

RESET Active Time tRST 100 150 250 ms 5

VCC Detect to RST tRPD 25 ms

VCC Slew Rate

(VCCTP (MAX) to VCCTP (MIN))

tF300 ms8

VCC Slew Rate

(VCCTP (MIN) to VCCTP (MAX))

tR0ns

VCC Detect to RST tRPU 100 150 250 ms 5, 6

Pushbutton Detect to RST tPB 1ms

Pushbutton Reset tPBRST 100 150 250 ms 5

DS1818

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NOTES:

1. All voltages are referenced to ground.

2. Measured with VCC ³ 2.7V.

3. A 1 kW external pull-up resistor may be required in some applications for proper operation of the

microprocessor reset control circuit.

4. Measured with RST output open.

5. Measured with 2.7V £ VCC £ 3.3V.

6. tR = 5 ms.

7. VOH and IOH are a function of the value of RP and the associated output load conditions.

8. The tF value is for reference in defining values for tRPD and should not be considered a requirement for

proper operation or use of the device.

PART MARKING CODES

“A”, “B”, &“C” represent the device type.

810 - DS1810

811 - DS1811

812 - DS1812

813 - DS1813

815 - DS1815

816 - DS1816

817 - DS1817

818 - DS1818

“D” represents the device tolerance.

A- 5%

B - 10%

C - 15%

D - 20%

ENGLISH • ???? • ??? • ???

WHAT'S NEW

PRODUCTS

SOLUTIONS

DESIGN

APPNOTES

SUPPORT

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DS1818

Part Number Table

Notes:

See the DS1818 QuickView Data Sheet for further information on this product family or download the DS1818 full data sheet

(PDF, 128kB).

Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.2.

Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.3.

Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: See full data sheet or Part

Naming Conventions.

* Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses.5.

Part Number

Notes

Free

Sample

Buy

Direct

Package:

TYPE PINS SIZE

DRAWING CODE/VAR *

Temp

RoHS/Lead-Free?

Materials Analysis

DS1818R-10/T&R/C01

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-20+T&R

3.3V-

20%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818R-5+T&R

3.3V-

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818R-20-U

3.3V-

20%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-10-U

3.3V-

10%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-5-U

3.3V-

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-20/T&R

3.3V-

20%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-10/T&R

3.3V-

10%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-5/T&R

3.3V-

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818R-10-U+

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818R-20-U+

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818R-5-U+

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818R-10+T&R

3.3V-

10%

SOT23;3 pin;50

Dwg: 21-0051G (PDF)

Use pkgcode/variation: U3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-20+T&R

3.3V-

20%

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-5+T&R

3.3V-

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-10+T&R

3.3V-

10%

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3+4*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-20/T&R

3.3V-

20%

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-10/T&R

3.3V-

10%

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-5/T&R

3.3V-

TO92;3 pin;185

Dwg: 56-G0006-003A (PDF)

Use pkgcode/variation: Q3-4*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-20

3.3V-

20%

Monitor

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3-1*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-10

3.3V-

10%

Monitor

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3-1*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-5

3.3V-

Monitor

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3-1*

-40C to +85C

RoHS/Lead-Free: No

Materials Analysis

DS1818-20+

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3+1*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-5+

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3+1*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

DS1818-10+

TO92;3 pin;185

Dwg: 56-G0006-001A (PDF)

Use pkgcode/variation: Q3+1*

-40C to +85C

RoHS/Lead-Free: Yes

Materials Analysis

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