Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsPMICsPMIC - system monitor Reset/power-on reset SOIC 8

 2002-2012 Microchip Technology Inc. Preliminary DS21370D-page 1

TC1232

Features

• Precision Voltage Monitor

- Adjustable +4.5V or +4.75V

• Reset Pulse Width – 250 msec minimum

• No External Components

• Adjustable Watchdog Timer

- 150 msec, 600 msec or 1.2 sec

• Operating Voltage 4.0V to 5.5V

• Debounced Manual Reset Input for External

Override

Block Diagram

General Description

The TC1232 is a fully-integrated processor supervisor

that provides three important functions to safeguard

processor sanity: precision power on/off reset control,

watchdog timer and external reset override.

On power-up, the TC1232 holds the processor in the

reset state for a minimum of 250 msec after V

within tolerance to ensure a stable system start-up.

Microprocessor sanity is monitored by the onboard

watchdog circuit. The microprocessor must provide a

periodic low-going signal on the ST

input. Should the

processor fail to supply this signal within the selected

time-out period (150 msec, 600 msec or 1200 msec),

an out-of-control processor is indicated and the

TC1232 issues a processor reset as a result.

The outputs of the TC1232 are immediately driven

active when the PB input is brought low by an external

push button switch or other electronic signal. When

connected to a push button switch, the TC1232

provides contact debounce.

The TC1232 is packaged in a space-saving 8-Pin PDIP

or SOIC package, a 16-Pin SOIC (wide) package and

requires no external components.

Package Types

Device Features

–

REF

–

RST

Toleran ce

Select

(5% or 10%)

TOL

Debounce

Watchdog

Timebase

Select

PB RST

Watchdog

Timer

Reset

Generator

Device

RST

pin RST pin

Trip Points

(Max)

Minimum

Reset

Active Time

(ms)

WDI Input

Typical

Timeouts (ms)

Input

Type

Pull-up

Resistor

Active

Level

Type

Active

Level

TC1232 Open-drain External Low Push-pull High 4.75V

or 4.5V

250 150, 600 or

1200

Yes

TC1232

RST

GND

TOL

PB RST

RST

RSTGND

TOL

PB RST

RST

PB RST

VCC

NC NC

TOL

GND

TC1232

16-Pin SOIC (Wide)8-Pin PDIP 8-Pin SOIC

TC1232

Microprocessor Monitor

Summary of content (20 pages)

PAGE 1
TC1232 Microprocessor Monitor Features General Description • Precision Voltage Monitor - Adjustable +4.5V or +4.75V • Reset Pulse Width – 250 msec minimum • No External Components • Adjustable Watchdog Timer - 150 msec, 600 msec or 1.2 sec • Operating Voltage 4.0V to 5.
PAGE 2
TC1232 1.0 ELECTRICAL CHARACTERISTICS † Stresses above 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 above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. Absolute Maximum Ratings† Voltage on Any Pin (With Respect to GND) ............
PAGE 3
TC1232 tF VCC tR +4.75V +4.75V +4.25V +4.25V VCC VCC = 5V 4.6V (5% Trip Point) +4.5V (5% Trip Point) 4.5V(10% Trip Point) +4.25V (10% Trip Point) VCC tRPU tRPD RST RST RST Determined by external Pull-up resistor FIGURE 1-1: VOH VOH VOL Determined by external Pull-up resistor VOL RST Rise Time, Fall Time and Reset Detected to Reset Active Timing Waveforms. AC CHARACTERISTICS Electrical Specifications: Unless otherwise noted, TA = TMIN to TMAX; VCC = +4.0V to 5.5V.
PAGE 4
TC1232 tPB ST tTD tST tPBD PB RST VIH VIL RST (when tTD  tTD (min)) tRST “H” RST (when tTD(min)  tTD  tTD(max)) RST RST RST (when tTD  tTD(max)) The debounced PB RST input ignores input pulses less than 1 ms and is designed to recognize pulses of 20 ms or greater. RST (when tTD  tTD(min)) “L” RST (when tTD(min)  tTD  tTD(max)) RST (when tTD  tTD(max)) FIGURE 1-2: Push Button Reset and Watchdog Timer Reset Timing Waveforms.
PAGE 5
TC1232 2.0 TYPICAL PERFORMANCE CURVES Performance Graphs are not available.  2002-2012 Microchip Technology Inc.
PAGE 6
TC1232 3.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 3-1. TABLE 3-1: PIN FUNCTION TABLES Pin No. Buffer/ Pin 8-pin Symbol Driver 16-pin Type PDIP, Type SOIC SOIC Function 1 2 PB RST I ST Push-button Reset Input. Input for a Manual Reset Switch. This input debounces (ignores) pulses less than 1 ms in duration and is ensured to recognize inputs of 20 ms or greater. L = Manual Reset Switch is Active, Force RST/RST pins Active H = Manual Reset Switch is Inactive.
PAGE 7
TC1232 4.0 OPERATIONAL DESCRIPTION 4.1 Power Monitor VCC = 5V +4.5V (5% Trip Point) The TC1232 provides the function of warning the processor of a power failure. When VCC is detected as being below the voltage levels defined by the TOL pin, the TC1232’s comparator outputs the RST and RST signals to a logic level that warns the system of an outof-tolerance power supply. The RST and RST signals switch at a threshold value of 4.5V if TOL is tied to VCC, and at a value of 4.75 volts if TOL is grounded.
PAGE 8
TC1232 4.2 Push Button Reset Input +5V The debounced manual reset input (PB RST) manually forces the reset outputs into their active states. Figure 4-5 shows a block diagram for using the TC1232 with a push button switch. VCC Once PB RST has been low for a time tPBD (the pushbutton delay time), the reset outputs go active. The reset outputs remain in their active states for a minimum of 250 ms after PB RST rises above VIH.
PAGE 9
TC1232 4.3 Watchdog Timer When the ST input is not stimulated for a preset time period, the watchdog timer function forces RST and RST signals to the active state. The preset time period is determined by the TD inputs to be 150 ms with TD connected to ground, 600 ms with TD floating or 1200 ms with TD connected to VCC (typ.). The watchdog timer starts timing-out from the set time period as soon as RST and RST are inactive.
PAGE 10
TC1232 5.0 PACKAGING INFORMATION 5.1 Package Marking Information 8-Lead PDIP (300 mil) XXXXXXXX XXXXXNNN YYWW TC1232 I/P256 0518 8-Lead SOIC (150 mil) XXXXXXXX XXXXYYWW NNN XXXXXXXXXXXXX XXXXXXXXXXXXX YYWWNNN Legend: XX...
PAGE 11
TC1232 8-Lead Plastic Dual In-line (PA) – 300 mil (PDIP) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.
PAGE 12
TC1232 8-Lead Plastic Small Outline (OA) – Narrow, 150 mil (SOIC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.
PAGE 13
TC1232 16-Lead Plastic Small Outline (OE) – Wide, 300 mil (SOIC) Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.
PAGE 14
TC1232 NOTES: DS21370D-page 14 Preliminary  2002-2012 Microchip Technology Inc.
PAGE 15
TC1232 APPENDIX A: REVISION HISTORY Revision D (November 2012) • Added a note to the package outline drawing. Revision C (June 2005) The following is the list of modifications: 1. 2. 3. 4. Since no data is given in Section 2.0 “Typical Performance Curves”, “Preliminary” was added to the bottom of this document.
PAGE 16
TC1232 NOTES: DS21370D-page 16 lPreliminary  2002-2012 Microchip Technology Inc.
PAGE 17
TC1232 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO.
PAGE 18
TC1232 NOTES: DS21370D-page 18 Preliminary  2002-2012 Microchip Technology Inc.
PAGE 19
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
PAGE 20
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