CAT1232LPL-GT2_技术文档

CAT1232LP/CAT1832

5V and 3.3V Supply Monitor, Watchdog Timer,

Manual Reset, with Active High & Low Resets

FEATURES

DESCRIPTION

ꢀ Selectable reset voltage tolerance

— CAT1232LP for 5V supply

— CAT1832 for 3.3V supply

The CAT1232LP and CAT1832 microprocessor

supervisors can halt and restart a “hung-up” or “stalled”

microprocessor, restart a microprocessor after a power

failure, and debounce a manual/push-button micro-

processor reset switch. The devices are drop in

replacements for the Maxim/Dallas Semiconductor

DS1232LP and DS1832 supervisors

ꢀ Selectable watchdog period:

150ms, 600ms or 1.2 sec

ꢀ Two reset outputs

Precision reference and comparator circuits monitor the

5V or 3.3V system power supply voltage, V_CC. During

power-up or when the power supply falls outside

selectabletolerancelimits, boththeRESETandRESET

become active. After the power supply voltage rises

above the RESET threshold voltage, the reset signals

remain active for a minimum of 250ms, allowing the

power supply and system processor to stabilize. The

trip-point tolerance input, TOL, selects the trip level

tolerance to be either 5% or 10% for the CAT1232LP 5V

supply and 10% or 20% for the CAT1832 3.3V supply.

— Active high, push-pull reset output

— Active low, open-drain reset output

(CAT1232LP)

— Active low, push-pull reset output (CAT1832)

ꢀ Debounced manual push-button reset

ꢀ Compact SOIC and MSOP packages

APPLICATIONS

ꢀ Microprocessor Systems

ꢀ Portable Equipment

ꢀ Controllers

Each device has a push-pull, active HIGH reset output.

The CAT1232LP also has an open drain, active LOW

reset output while the CAT1832 also has a push-pull,

active LOW reset output.

ꢀ Single Board Computers

ꢀꢀ Instrumentations

A debounced manual reset input activates the reset

outputs and holds them active for a minimum period of

250ms after being released.

ꢀ Telecommunications

Also included is a watchdog timer to reset a

microprocessor that has stopped due to a software or

hardware failure. Three watchdog time-out periods are

selectable: 150ms, 600ms and 1.2sec. If the ST input is

not strobed low before the watchdog time out period

expires, the reset signals become active for a minimum

of 250ms.

For Ordering Information details, see page 11.

FUNCTIONAL DIAGRAM

VCC

(CAT1232LP)

RESET

TOL

Tolerance Selection

Reference

+

V_CC

–

40kΩ

RESET

PBRST

TD

Push Button Debounce

Watchdog Timebase Selection

Watchdog Transition Detector

Reset &

Watchdog Timer

(CAT1832)

ST

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

1

CAT1232LP/CAT1832

PIN CONFIGURATION

16-Lead SOIC

8-Lead SOIC/MSOP/DIP

PBRST

TD

1

2

3

4

8

7

6

5

V

CC

NC

PBRST

NC

1

2

3

4

5

6

7

8

16 NC

15 V

ST

CC

TOL

RESET

14 NC

GND

TD

13 ST

NC

12 NC

TOL

NC

11 RESET

10 NC

GND

9 RESET

PIN DESCRIPTION

Pin Number

8-Lead Package 16-Lead Package

Pin Number

Name

PBRST

TD

Function

1

2

4

Debounced manual pushbutton reset input

Watchdog typical time delay selection:

a) t_TD= 150ms for TD = GND

b) t_TD= 600ms for TD = Open

c) t_TD= 1200ms for TD = V_CC

3

6

TOL

CAT1232LP TOL selects 5% (TOL = GND) or 10% (TOL = V_CC) trip

point tolerance. CAT1832 TOL selects 10% (TOL = GND) or 20% TOL =

V_CC) trip point tolerance.

4

5

8

9

GND

Ground

RESET Active HIGH reset output. RESET is active

1. If V_CCfalls below the reset voltage trip point

2. If PBRST is low

3. If ST is not strobed low before the timeout period set by TD expires.

4. During power-up.

6

7

8

11

13

15

Active LOW reset output. (See RESET)

Strobe Input

RESET

ST

V_CC

Power Supply

1, 3. 5, 7, 10, 12,

14, 16

NC

No internal connection

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

2

CAT1232LP/CAT1832

ABSOLUTE MAXIMUM RATINGS*

Voltage on V_CC....................................... -0.5V to 7.0V

Maximum Junction Temperature ...................... 125°C

Storage Temperature Range ............ -65°C to +150°C

Lead Soldering Temperature (10 sec).............. 300°C

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

Voltage on ST and TD ................. -0.5V to V_CC+ 0.5V

Voltage on PBRST, RESET

and RESET ............................ -0.5V to V_CC+ 0.5V

ELECTRICAL CHARACTERISTICS

Unless otherwise stated, 1.0V ≤ V

≤ 5.5V and over the operating temperature range of -40°C to +85°C. All

CC

voltages are referenced to ground.

Symbol Parameter

Conditions

Min

Typ

Max

5.5

50

Units

V_CC

Supply Voltage

1.0

V

_CC= 5.5V, CAT1232LP

35

20

I_CC1

Supply Current

µA

V

V_CC= 3.6V, CAT1832

(5)

35

2

V_IH

V_IL

V_CC+ 0.3V

0.8

ST and PBRST Input High Level

ST and PBRST Input Low Level

(6)

V_CC- 0.4V

– 0.3

V_CC= 5.5V, CAT1232LP

V

V_CC= 3.6V, CAT1832

0.5

V_CCTPV_CCTrip Point (TOL = GND)

V_CCTPV_CCTrip Point (TOL = V_CC

V_CCTPV_CCTrip Point (TOL = GND)

V_CCTPV_CCTrip Point (TOL = V_CC

t_TDWatchdog Time-Out Period

t_TD

CAT1232LP

4.50

4.25

4.62

4.37

4.74

4.49

V

)

CAT1832

2.80

2.47

2.88

2.55

2.97

2.64

V

)

TD = GND

TD = V_CC

62.5

500

250

150

1200

600

250

2000

1000

ms

V

Watchdog Time-Out Period

Output Voltage

t_TD

TD floating

I = – 500µA⁽³⁾

V_OH

V_CC- 0.5V V_CC- 0.1V

I_OH

I_OL

Output Current

Output = 2.4V⁽²⁾

– 350

µA

Output = 0.4V,

10

mA

(1)

I_IL

Input Leakage

– 1.0

1.0

55

µA

(1)

R_PU

Internal Pull-Up Resistor

32

40

kΩ

C_IN

Input Capacitance

Output Capacitance

5

7

pF

C_OUT

t_PB

pF

20

ms

PBRST Manual Reset

PBRST = V_IL

Minimum Low Time

t_RST

Reset Active Time

250

20

600

5

1000

8

ms

(4)

t_ST

ns

µs

ST Pulse Width

t_RPD

V_CCFail Detect to

RESET or RESET

t_F

V_CCSlew Rate

20

µs

t_PDLY

20

ms

PBRST Stable LOW to

RESET and RESET Active

t_RPU

V_CCDetect to RESET or

RESET Inactive

t_RISE= 5µs

250

0

600

1000

ms

ns

t_R

V_CCSlew Rate

4.25V to 4.75V

Notes:

(1) PBRST is internally pulled HIGH to V through a nominal 40kΩ

(4) Must not exceed the minimum watchdog time-out period (t ).

CC

TD

resistor (R ).

The watchdog circuit cannot be disabled. To avoid a reset, ST

PU

must be strobed.

(2) RESET is an open drain output on the CAT1232LP.

(5) Measured with V ≥ 2.7V.

CC

(3) RESET remains within 0.5V of V on power-down until V falls

CC

below 2V. RESET remains within 0.5V of ground on power-down

(6) Measured with V < 2.7V.

CC

until V falls below 2.0V.

CC

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

3

CAT1232LP/CAT1832

TYPICAL CHARACTERISTICS

For the CAT1232LP, V_CC= 5V and T_AMB= 25°C unless otherwise stated.

Threshold Voltage vs. Temperature (10% TOL)

Threshold Voltage vs. Temperature (5% TOL)

4.630

4.625

4.620

4.615

4.610

4.450

4.445

TOL = GND (5%)

TOL = Vcc (10%)

4.440

4.435

4.430

-50

0

50

100

-50

0

50

100

TEMPERATURE (°C)

Supply Current vs. Temperature

Reset Active Time vs. Temperature

40

800

Vcc = 5.5V

30

TD = open

700

600

500

400

300

Vcc = 5.5V

Vcc = 4.5V

20

Vcc = 4.5V

10

0

-50

0

50

100

-50

0

50

100

TEMPERATURE (°C)

Reset Active Time Waveform

Transient Response

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

4

CAT1232LP/CAT1832

APPLICATION INFORMATION

Connecting TOL to VCC makes the VCC trip threshold

4.37V for the CAT1232LP and 2.55V for the CAT1832.

SUPPLY VOLTAGE MONITOR

After V_CChas risen above the trip point set by TOL,

RESET and RESET remain active for a minimum time

period of 250ms.

Reset Signal Polarity and Output Stage Structure

RESET is an active LOW signal. It is developed with an

open drain driver in the CAT1232LP. A pull-up resistor

is required, typical values are 10kΩ to 50kΩ. The

CAT1832 uses a CMOS push-pull output stage for the

RESET.

Onpower-down,onceV_CCfallsbelowtheresetthreshold

theRESEToutputswillremainactiveandareguaranteed

valid down to a V_CClevel of 1.0V.

RESET is an active High signal developed by a CMOS

push-pull output stage and is the logical opposite to

RESET.

Tolerance

Select

Trip Point Voltage (V)

Trip Point

Tolerance

MIN

NOMINAL

4.37

MAX

Voltage

Trip Point Tolerance Selection

CAT1232LP

TOL = V_CC

10 %

5 %

4.25

4.50

2.47

2.80

4.49

4.74

2.64

2.97

The TOL input is used to select the V_CCtrip point

threshold. This selection is made connecting the TOL

input to ground or V_CC. Connecting TOL to Ground

makes the V_CCtrip threshold 4.62V for the CAT1232LP

and 2.88V for the CAT1832.

CAT1232LP

TOL = GND

4.62

2.55

2.88

CAT1832

TOL = V_CC

20 %

10 %

CAT1832

TOL = GND

t_F

t_R

V_CC

V_CCTP(MAX)

V_CCTP

V_CCTP(MAX)

V_CCTP

V_CCTP(MIN)

V_CC

t_RPU

RESET

t_RPD

RESET

V_OH

V_OL

RESET

Figure 1. Timing Diagram: Power Up

Figure 2. Timing Diagram: Power Down

Manual Reset Operation

Push-button input, PBRST, allows the user to issue

reset signals. The pushbutton input is debounced and is

pulled high through an internal 40kΩ resistor.

No external pull-up resistor is required, since PBRST is

pulled high by an internal 40kΩ resistor.

PBRST can be driven from a TTL or CMOS logic line or

When PBRST is held low for the minimum time of 20 ms,

both resets become active and remain active for a

minimum time period of 250ms after PBRST returns

high.

short-ed to ground with a mechanical switch.

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

5

CAT1232LP/CAT1832

WATCHDOG TIMER AND ST INPUT

A watchdog timer stops and restarts a microprocessor

that has stopped proper operation or become “hung”.

The watchdog performs this function by monitoring the

ST input. After the reset outputs go inactive the ST input

must be strobed with a high-to-low signal transition prior

totheminimumwatchdogtimeoutperiod. Howeverifthe

ST input is not strobed with a high-to-low signal transi-

tion prior to a watchdog timeout the reset outputs will

become active for T_RSTreseting and restarting the

microprocessor. Once the resets return to the inactive

state the watchdog timer restarts the process.

Watchdog Time-out Period (ms)

TD Voltage

Level

MIN

NOMINAL

150

MAX

GND

Floating

V_CC

62.5

250

500

250

1000

2000

600

1200

3.3V

CAT1832

8

7

6

5

1

The TD input allows the user to select from three

predetermined watchdog timeout periods. Always use

the minimum timeout period to determine the required

frequency of ST high-to-low transitions and the maxi-

mum to determine the time prior to the reset outputs

becoming active. ST pulse widths must be 20ns or

greater.

PBRST

TD

V

CC

ST

2

3

4

I/O

µP

TOL

RESET

GND RESET

RESET

The watchdog timer cannot be disabled. It must be

strobed with a high-to-low signal transition to avoid a

watchdog timeout and subsequent reset.

Figure 4. CAT1832 Application Circuit:

Pushbutton Reset

5V

CAT1232LP

8

7

6

5

1

2

3

4

MREQ

PBRST

TD

V

CC

ST

10k

µP

RESET

Address

Bus

Decoder

TOL

RESET

GND RESET

Figure 5. CAT1232LP Application Circuit: Watchdog Timer

t_PB

Valid

Strobe

Valid

Strobe

Invalid

Strobe

PBRST

t_PDLY

V

ST

IH

V

IL

t_ST

t_TD

t_RST

t_TD

t_RST

(Min)

RESET

V_OH

V_OL

Note:ST is ignored whenever a reset is active.

Figure 6. Timing Diagram: Pushbutton Reset

Figure 7. Timing Diagram: Strobe Input

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

6

CAT1232LP/CAT1832

PACKAGE DRAWING

16-LEAD WIDE BODY SOIC (300mil)

E1

E

h x 45

D

C

A

θ1

e

A1

L

b

SYMBOL

MIN

0.10

2.36

0.33

0.23

10.10

10.00

7.40

NOM

MAX

0.30

2.65

0.51

0.32

10.50

10.65

7.60

A1

A

2.49

0.41

b

C

D

E

0.28

10.31

7.50

E1

e

1.27 BSC

h

0.25

0.40

0°

0.75

1.27

8°

16-Lead_SOIC_(300mil).eps

L

0.81

θ

1

For current Tape and Reel information, download the PDF file from:

http://www.catsemi.com/documents/tapeandreel.pdf.

Notes:

1. All dimensions are in millimeters.

2. Complies with JEDEC specification MS-013.

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

7

CAT1232LP/CAT1832

PACKAGE DRAWING

8-LEAD DIP (300mil)

E1

E

D

A2

A

L

A1

e

eB

b2

b

SYMBOL

MIN

NOM

MAX

A

A1

A2

b

4.57

0.38

3.05

0.36

1.14

9.02

7.62

6.17

3.81

0.56

1.52

10.16

8.26

7.49

0.46

b2

D

E

7.87

6.35

E1

e

2.54 BSC

eB

L

7.87

2.79

9.65

3.81

24C16_8-LEAD_DIP_(300P).eps

For current Tape and Reel information, download the PDF file from:

http://www.catsemi.com/documents/tapeandreel.pdf.

Notes:

1. All dimensions are in millimeters.

2. Complies with JEDEC Standard MS001.

3. Dimensioning and tolerancing per ANSI Y14.5M-1982

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

8

CAT1232LP/CAT1832

PACKAGE DRAWING

8-LEAD MSOP

E1

E

e

D

GAUGE

PLANE

A2

A

L

b

A1

SYMBOL

MIN

NOM

MAX

1.10

0.15

0.95

0.38

3.10

5.00

3.10

A

A1

A2

b

0.00

0.75

0.22

2.90

4.80

2.90

D

3.00

4.90

E

E1

e

3.00

0.65 BSC

L

0.40

0.8

0°

8°

8-lead_MSOP3.eps

For current Tape and Reel information, download the PDF file from:

http://www.catsemi.com/documents/tapeandreel.pdf.

Notes:

1. All dimensions are in millimeters. Angles in degrees.

2. Complies with JEDEC Specification MO-187.

3. Stand off height/coplanarity are considered as special characteristics.

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

9

CAT1232LP/CAT1832

PACKAGE MECHANICAL

8-LEAD Narrow Body SOIC (150mil)

E1

E

h x 45

D

C

A

θ1

e

A1

L

b

SYMBOL

MIN

0.10

1.35

0.33

0.19

4.80

5.80

3.80

NOM

MAX

0.25

1.75

0.51

0.25

5.00

6.20

4.00

A1

A

b

C

D

E

E1

e

1.27 BSC

h

0.25

0.40

0°

0.50

1.27

8°

24C16_8-LEAD_SOIC.eps

L

θ

1

For current Tape and Reel information, download the PDF file from:

http://www.catsemi.com/documents/tapeandreel.pdf.

Notes:

1. All dimensions are in millimeters. Angles in degrees.

2. Complies with JEDEC Specification MS-012.

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

10

CAT1232LP/CAT1832

SAMPLE OF ORDERING INFORMATION

Prefix

Device #

1232LP

Suffix

CAT

V

–

G

T3

Company ID

Product Number

1232 LP

1832

T: Tape & Reel

2: 2000/Reel

3: 3000/Reel

Package

L: PDIP (Lead-free, Halogen-free)

V: SOIC 8-Lead (Lead-free, Halogen-free)

W: SOIC 16-Lead (Lead-free, Halogen-free)

Z: MSOP (Lead-free, Halogen-free)

Lead Finish

Blank: Matte-Tin

G: NiPdAu

Notes:

(1) All packages are RoHS-compliant (Lead-free, Halogen-free).

(2) The standard lead finish is NiPdAu.

(3) The device used in the above example is a CAT1232LPV-GT3 (SOIC, NiPdAu, Tape & Reel).

(4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office.

Green NiPdAu Lead Finish

Ordering Part Number

CAT1232LPL-G

Package

8-lead, DIP

8-lead, SOIC

MSOP

Parts per Tube

Parts Per Reel

—

Reel Size (inch)

50

—

13

CAT1232LPV-GT3

CAT1232LPZ-GT3

CAT1232LPW-GT2

3,000

16-lead, SOIC

2,000

CAT1832L-G

CAT1832V-GT3

CAT1832Z-GT3

8-lead, DIP

8-lead, SOIC

MSOP

50

—

13

3,000

Characteristics subject to change without notice

Doc. No. 25089, Rev. 0C

11

REVISION HISTORY

Date

Revision Comments

06/13/2005

07/26/2005

00

0A

Initial Issue

Update Electrical Characteristics

Add Typical Characteristics

03/27/2006

08/21/2006

0B

0C

Update Document Title

Update Ordering Information

Add Ordering Information detail to page 1

Update Sample of Ordering Information

Copyrights, Trademarks and Patents

Trademarks and registered trademarks of Catalyst Semiconductor include each of the following:

DPP ™

AE²™

Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products.

CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS

PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE

RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING

OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES.

Catalyst Semiconductor products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or

other applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a

situation where personal injury or death may occur.

Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets

labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale.

Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate

typical semiconductor applications and may not be complete.

Catalyst Semiconductor, Inc.

Corporate Headquarters

2975 Stender Way

Santa Clara, CA 95054

Phone: 408.542.1000

Fax: 408.542.1200

www.catsemi.com

Publication #: 25089

Revison:

0C

Issue date:

08/21/06


型号：	CAT1232LPL-GT2
厂家：	CATALYST SEMICONDUCTOR
描述：	5V and 3.3V Supply Monitor, Watchdog Timer, Manual Reset, with Active High & Low Resets 5V和3.3V电源监视器，看门狗定时器，手动复位，与Active高，低复位监视器
文件：	总12页 (文件大小：179K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

CAT1232LPL-GT2 [CATALYST]

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