MIC706P [MICREL]

レP Supervisory Circuits; μP监控电路


型号：	MIC706P
厂家：	MICREL SEMICONDUCTOR
描述：	レP Supervisory Circuits μP监控电路监控
文件：	总8页 (文件大小：185K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

MIC706P/R/S/T, MIC708R/S/T

µP Supervisory Circuits

Description

Pin Configuration

Top View

The MIC706P/R/S/T and MIC708R/S/T are inexpensive

microprocessor supervisory circuits that monitor power

supplies in 3.0 and 3.3 Volt microprocessor based

systems. The circuit functions include a watchdog timer,

microprocessor reset, power failure warning and a

debounced manual reset input.

N Package - 8 Lead Plastic DIP Package

M Package - 8 Lead Plastic SOIC Package

The MIC706 offers a watchdog timer function, while the

MIC708 has no watchdog timer but has an active high

reset output in addition to the active low reset output.

The R, S, and T versions are similar in all respects

except for supply voltage reset threshold levels. The

threshold levels are 2.63, 2.93, and 3.08V respectively.

When the supply voltage drops below the reset

threshold level, RESET (and RESET for the MIC708) is

asserted.

Features

The MIC706P is identical to the MIC706R, except that

the Reset output is asserted high.

30µA Maximum Supply Current

Debounced Manual Reset Input is

TTL/CMOS Compatible

Typical Applications

Reset Pulse Width, 200ms

Laptop Computers

Watchdog Timer, 1.6s (MIC706)

Intelligent Instruments

Precision Supply Voltage Monitor

Critical Microprocessor Power Monitoring

Printers

Early Power Fail Warning or Low Battery

Detect

Computers

Controllers

Typical Operating Circuit

Ordering Information

Part

Package

Temp. Range

-40°C to +85°C

MIC70_ _N

MIC70_ _M

8-Lead PDIP

8-Lead SOIC

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Absolute Maximum Ratings

Terminal Voltage

Operating Temperature Range

. . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V

MIC70_N, MIC70_M . . . . . . . . . . . . . . . . . -40°C to 85°C

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

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

Power Dissipation (PDIP) . . . . . . . . . . . . . . . . . . . . 475mW

Power Dissipation (SOIC) . . . . . . . . . . . . . . . . . . . . 400mW

All Other Inputs . . . . . . . . . . . . -0.3V to (V

Input Current

+ 0.3V)

Gnd. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25mA

CC,

Output Current (all outputs) . . . . . . . . . . . . . . . . . 20mA

Stresses above those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent device failure. Functionality at or above these limits is not implied. Exposure to absolute

maximum ratings for extended periods may affect device reliability. Operating ranges define those limits between which the functionality of the device is guaranteed.

Electrical Characteristics

= 2.70V to 5.5V for MIC70_P/R, V

= 3.00V to 5.5V for MIC70_S, V = 3.15V to 5.5V for MIC70_T, T = -40°C to 85°C

unless otherwise noted.

Parameter

Conditions

Min

Typ

Max

Units

Operating Voltage Range, V

1.4

5.5

Supply Current

µA

Reset Voltage Threshold

MIC70_P/R

MIC70_S

MIC70_T

2.55

2.85

3.00

2.63

2.93

3.08

2.70

3.00

3.15

Reset Threshold Hysteresis

Reset Pulse Width, t

140

200

280

RESET Output Voltage

(MIC70_R/S/T)

= 200µA

= 1.2mA

0.8 x

Source

Sink

0.3

= 50µA, V

= 1.4V

RESET Output Voltage

(MIC706P)

= 200µA

= 1.2mA

0.8 x

Source

Sink

0.3

RESET Output Voltage

(MIC708R/S/T)

= 200µA

= 500µA

Source

Sink

0.3

Watchdog Timeout Period, t

1.0

1.6

2.25

sec

WDI Minimum Input Pulse, t

WDI Threshold Voltage

= 0.4V, V = 80% of V

IH CC

100

= 0.4V, V = 80% of V >4.5V

IH CC

0.7 x V

0.6

WDI Input Current

WDI = 0V or V

-1

µA

WDO Output Voltage

= 200µA

0.8 x

Source

= 500µA

0.3

Sink

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Electrical Characteristics

= 2.70V to 5.5V for MIC70_P/R, V

= 3.00V to 5.5V for MIC70_S, V = 3.15V to 5.5V for MIC70_T, T = -40°C to 85°C

unless otherwise noted.

Parameter

Conditions

Min

Typ

Max

Units

MR Pull-Up Current

MR = 0V

250

600

µA

MR Pulse Width, t

500

150

> 4.5V

MR Input Threshold

0.6

0.7 x

MR to Reset Output Delay, t

PFI Input Threshold

750

1.3

1.2

-25

1.25

0.01

PFI Input Current

+25

0.3

PFO Output Voltage

= 1.2mA

Sink

= 200µA

0.8 x V

Source

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Pin Functions

Pin No.

Pin Name

MIC706

R/S/T

MIC706P

MIC708

Manual Reset Input forces reset outputs to assert when

pulled below 0.8V. An internal pull-up current of 250µA on

this input forces it high when left floating. This input can

also be driven from TTL or CMOS logic.

Primary supply input, +5V.

IC ground pin, 0V reference.

VCC

GND

PFI

Power fail input. Internally connected to the power fail

comparator which is referenced to 1.25V. The power fail

output (PFO) remains high if PFI is above 1.25V. PFI

should be connected to GND or V

comparator is not used.

if the power fail

OUT

Power fail output. The power fail comparator is

independent of all other functions on this device.

PFO

WDI

Watchdog input. The WDI input monitors microprocessor

activity, an internal watchdog timer resets itself with each

transition on the watchdog input. If the WDI pin is held high

or low for longer than the watchdog timeout period, WDO is

forced to active low. The watchdog function cannot be

disabled.

N/A

No Connect

N/C

N/A

RESET is asserted if either V

goes below the reset

RESET

threshold or by a low signal on the manual reset input (MR).

RESET remains asserted for one reset timeout period

(200ms) after V

exceeds the reset threshold or after the

manual reset pin transitions from low to high. The

watchdog timer will not assert RESET unless WDO is

connected to MR.

Output for the watchdog timer. The watchdog timer resets

itself with each transition on the watchdog input. If the WDI

pin is held high or low for longer than the watchdog timeout

period, WDO is forced low. WDO will also be forced low if

WDO

N/A

is below the reset threshold and will remain low until

returns to a valid level.

RESET is the compliment of RESET and is asserted if

either V goes below the reset threshold or by a low

RESET

N/A

signal on the manual reset input (MR). RESET is suitable

for microprocessors systems that use an active high reset.

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Block Diagram

* 2.63, 2.93, or 3.08V

Figure 1. MIC706 Block Diagram

* 2.63, 2.93, or 3.08V

Figure 2. MIC708 Block Diagram

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Circuit Description

Power Fail Warning

An additional comparator which is independent of other

functions on the MIC706/MIC708 is provided for early

warning of power failure. An external voltage divider

the WDI pin will reset the watchdog timer. The output of

the watchdog timer (WDO) will remain high if WDI sees

a valid transition within the watchdog timeout period. If

falls below the reset threshold voltage then WDO

goes low immediately regardless of WDI. Likewise,

WDO goes high immediately after V exceeds the

Unregulated DC

reset threshold. WDO can be connected to MR to

generate a reset pulse upon watchdog timeout.

PFI

Microprocessor Reset

The RESET pin is asserted whenever V

the reset threshold voltage or when MR goes low. The

reset pin remains asserted for a period of 200ms after

falls below

PFO

1.25V

Figure 3. Power Fail Comparator

can be used to compare unregulated DC to an internal

1.25V reference. The voltage divider ratio on the input

of the power fail comparator (PFI) can be chosen so as

to trip the power fail comparator a few milliseconds

before V

CC falls below the maximum reset threshold

voltage. The output of the power fail comparator (PFO)

can be used to interrupt the microprocessor when used

in this mode and execute shut-down procedures prior to

power loss.

Figure 4. Reset Timing Diagram

Watchdog Timer

The microprocessor can be monitored by connecting

the WDI pin (watchdog input) to a bus line or I/O line. If

a transition doesn’t occur on the WDI pin within the

watchdog timeout period, then WDO will go low. A

minimum pulse of 50ns (4.5V supply) or 100ns (2.7V

supply) or any transition low-to-high or high-to-low on

has risen above the reset threshold voltage and

MR goes high. The reset function ensures the

microprocessor is properly reset and powers up into a

known condition after a power failure. RESET will

remain valid with V

as low as 1.4V.

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Alternate Source Cross Reference Guide

MIC Direct

Industry P/N

MAX706PCPA

MAX706PCSA

MAX706PEPA

MAX706PESA

DS706PEPA

DS706PESA

MAX706RCPA

MAX706RCSA

MAX706REPA

MAX706RESA

DS706REPA

DS706RESA

MAX706SCPA

MAX706SCSA

MAX706SEPA

MAX706SESA

DS706SEPA

DS706SESA

MAX706TCPA

MAX706TCSA

MAX706TEPA

MAX706TESA

DS706TEPA

DS706TESA

MAX708RCPA

MAX708RCSA

MAX708REPA

MAX708RESA

DS708REPA

DS708RESA

MAX708SCPA

MAX708SCSA

MAX708SEPA

MAX708SESA

DS708SEPA

Replacement

MIC706PN

MIC706PM

MIC706PN

MIC706PM

MIC706PN

MIC706PM

MIC706RN

MIC706RM

MIC706RN

MIC706RM

MIC706RN

MIC706RM

MIC706SN

MIC706SM

MIC706SN

MIC706SM

MIC706SN

MIC706SM

MIC706TN

MIC706TM

MIC706TN

MIC706TM

MIC706TN

MIC706TM

MIC708RN

MIC708RM

MIC708RN

MIC708RM

MIC708RN

MIC708RM

MIC708SN

MIC708SM

MIC708SN

MIC708SM

MIC708SN

MIC708SM

MIC708TN

MIC708TM

MIC708TN

MIC708TM

MIC708TN

MIC708TM

DS708SESA

MAX708TCPA

MAX708TCSA

MAX708TEPA

MAX708TESA

DS708TEPA

DS708TESA

MIC706P/R/S/T, MIC708R/S/T µP Supervisory Circuits

Packaging Information

M Package, 8-Pin Small Outline

N Package, 8-Pin Plastic Dual-In-Line

0.400

0.370

0.260

0.240

0.310

0.290

0.150

0.035

0.120

0.015

0.150

0.125

0.110

0.090

0.370

0.300

0.023

0.015

MIC706P [MICREL]

相关型号：

MIC706PM

MIC706PMY

MIC706PN

MIC706P_06

MIC706R

MIC706RM

MIC706RMTR

MIC706RMY

MIC706RN

MIC706R_11

MIC706R_14

MIC706S