· Selectable trip-point tolerance and watchdog period
 
       
     
   
  · Selectable trip-point tolerance and watchdog period
  · Active LOW and active High push-pull reset outputs
 
       
     
   
  · Low Power Supervisors
 
       
     
   
  · Low Power μP Supervisors
 
       
     
   
  · Dual 5V/3.3V microprocessor supervisors
 
       
     
   
  · Low power supervisors reduce current by 60%
 
       
     
   
  · Microprocessor Supervisors with Watchdog Timer, Battery Backup Switch and Power Fail Indicator
 
       
     
   
  · 3/3.3/4V Microprocessor Supervisors with Power Fail Indicator and Improved Watchdog Timer
 
       
     
   
  · Microprocessor Supervisors with Watchdog Timer and Power Fail Indicator
 
       
     
   
  · Low Power, Low Cost Microprocessor Supervisors, 75% Lower Power Supply Current than Maxim
 
       
     
    IMP1232LP 5V Low Power Supervisor  
       
    The IMP1232LP/LPS microprocessor supervisor can halt and restart a "hung-up" or "stalled" microprocessor, restart a microprocessor after a power failure, and debounce and interface a manual push-button microprocessor reset switch. The low-power supervisors feature 40% lower supply current than the pin compatible Dallas Semiconductor DS1232LP/LPS devices.

Precision temperature compensated reference and comparator circuits monitor the 5V, VCC input voltage. During power-up or when the VCC power supply falls outside selectable tolerance limits, both the RESET and RESET (bar, active LOW) become active. When VCC rises above the threshold voltage, the reset signals remain active for an additional 250ms minimum, allowing the power supply and system microprocessor to stabilize. The trip point tolerance signal, TOL, selects the trip level tolerance to be either 5- or 10-percent.

Each device has both a push-pull, active HIGH reset output and an open drain, active LOW reset output. A debounced manual reset input activates the reset outputs for a minimum period of 250ms.

Also included is a watchdog timer to stop and restart a microprocessor that is "hung-up". Watchdog time-out periods of 150ms, 610ms and 1,200ms are user selectable. If the ST input is not strobed LOW before the time-out period expires, a reset is issued.

Devices are available in 8-pin DIP, 8/16-pin SO and compact 8-pin MicroSO packages.

 
       
    · Key Features  
       
   
  • User selectable threshold tolerance via TOL pin
    - 5% for 4.74V max. threshold and 10% for 4.49V

  • Selectable watchdog timer period via TD pin: 150ms/610ms/1.2sec
  • 40% lower power supply current than Dallas
    - 30m A maximum (IMP) vs 50m A for Dallas

  • Dual reset outputs: Active LOW (open drain) and Active HIGH
    - 250ms minimum reset period

  • 8-pin package options: DIP, SO and compact MicroSO
  • MicroSO footprint 50% smaller than the SO
  • 16-pin package option: SO
  • Debounced manual reset pin
 
       
    · Data Sheets  
   
  · IMP1232LP   
 
       
     
    IMP1832 3.3V Low Power Supervisor  
       
    The IMP1832 microprocessor supervisor can halt and restart a "hung-up" or "stalled" microprocessor, restart a microprocessor after a power failure, and debounce and interface a manual push-button microprocessor reset switch. The low-power supervisors feature 40% lower supply current than the pin compatible Dallas Semiconductor DS1832 devices.

Precision temperature compensated reference and comparator circuits monitor the 3/3.3VV, VCC input voltage. During power-up or when the VCC power supply falls outside selectable tolerance limits, both the active HIGH and active LOW reset outputs become active. When VCC rises above the threshold voltage, the reset signals remain active for an additional 250ms minimum, allowing the power supply and system microprocessor to stabilize. The trip point tolerance signal, TOL, selects the trip level tolerance to be either 10- or 20-percent.

Each device has both a push-pull active HIGH reset and a push-pull active LOW output. A debounced manual reset input activates the reset outputs for a minimum period of 250ms.

Also included is a watchdog timer to stop and restart a microprocessor that is "hung-up". Watchdog time-out periods of 150ms, 610ms and 1,200ms are user selectable. If the ST input is not strobed LOW before the time-out period expires, a reset is issued.

Devices are available in 8-pin DIP, 8-pin SO and compact 8-pin MicroSO packages.

 
       
    · Key Features  
       
   
  • User selectable threshold tolerance via TOL pin
    - 10% for 2.97V max. threshold and 20% for 2.64V max. threshold

  • Selectable watchdog timer period via TD pin: 150ms/610ms/1.2sec
  • 40% lower power supply current than Dallas
    - 20m A maximum (IMP) vs 35m A for Dallas

  • Dual reset outputs: Active LOW (open drain) and Active HIGH
    - 250ms minimum reset period

  • 8-pin package options: DIP, SO and compact MicroSO
  • MicroSO footprint 50% smaller than the SO
  • Debounced manual reset pin
 
       
    · Data Sheets  
   
  · IMP1832   
 
       
     
    IMP161, IMP162 Supervisor with Edge Triggered Manual Reset  
       
    The IMP161 and IMP162 are low power supervisory circuits that monitor power supplies in microprocessor based systems. If the power supply drops below the reset threshold level, a reset is asserted and remains asserted for at least 800ms after VCC has risen above the reset threshold. An improved manual reset architecture gives the system designer additional flexibility.

The debounced manual reset input is negative edge triggered. The reset pulse period generated by a MR transition is a minimum of 800ms and maximum of 2 sec. In addition, the MR input signal is blocked for an additional 49S minimum after the reset pulse ends. During the MR disable period, the microcontroller is guaranteed a time period free of additional manual reset signals. During this period DRAM contents can be refreshed or other critical system tasks undertaken.

Low supply current makes the IMP161/162 ideal for use in battery operated equipment. With 3V supplies power consumption is 8m W typically and 30m W maximum.

The IMP161 has an open-drain, active-LOW RESET output and uses an external pull-up resistor. The IMP162 has an active-HIGH RESET output. Available in compact 4-pin SOT-143 packages, six voltage thresholds are offered to support 3.0V, 3.3V and 5V power systems.

 
       
    · Key Features  
       
   
  • Edge triggered manual reset input
    - Single pulse output
    - 49μS minimum MR disable period after reset
    - CMOS/TTL logic or switch interface
    - Debounced input

  • Low supply current extends battery life
    - 6μA/15μA typ/max at 5.5V
    - 4.5μA/10μA typ/max at 3.6V

  • Long reset period
    - 0.8 sec minimum, 2 sec maximum

  • Two reset polarity options
    - IMP161: Active LOW, open-drain
    - IMP162: Active HIGH

  • Pinout matches the IMP811/812
  • Small 4-pin SOT-143 package
 
       
    · Data Sheets  
   
  · IMP161, IMP162   
 
       
     
    IMP1810/1811/1812/1815/1816/1817 Supervisors  
       
    The IMP1810, IMP1811, IMP1812, IMP1815, IMP1816 and IMP1817 microprocessor supervisory and reset circuits are lower power, direct replacements for devices originally offered by Dallas Semiconductor. The IMP devices reduce supply current requirements by up to 57 percent when compared to Dallas Semiconductor devices. Maximum supply current is as low as 15 microamperes. Typical supply current is 8 microamperes.

Both open-drain and push-pull reset output stages with active HIGH or active LOW reset signals are offered. No external components are required, which reduces the overall system cost and complexity while increasing the system reliability. The reset period is 150 milliseconds.

 
       
    · Product Summary Table  
       
    All devices operate over an operating temperature range of -40 degrees centigrade to +85 degrees centigrade.  
       
 
IMP Part
Output Stage

RESET Polarity

System Supply

IMP1810
Push-Pull
LOW
5V
IMP1811
Open-Drain
LOW
5V
IMP1812
Push-Pull
HIGH
5V
IMP1815
Push-Pull
LOW
3/3.3V
IMP1816
Open-Drain
LOW
3/3.3V
IMP1817
Push-Pull
HIGH
3/3.3V
 
       
    · Data Sheets  
   
  · IMP1810/11/12/15/16/17, IMP1233D, IMP1233M   
 
       
     
    IMP1834, IMP1834A, IMP1834D  
       
    The IMP1834 microprocessor supervisors serve applications where both 3.3-volt and 5-volt power supplies must be monitored. Compared to competitive offerings, IMP devices operate with up to 40 percent lower supply current.

40 Percent Lower Supply Current

The IMP1834 family offers up to 40 percent lower supply current. The 5-volt supply current is typically 16 microamperes and is 30-microamperes maximum. This compares to a 50-microampere maximum specification for Dallas Semiconductor devices.

Selectable Reset Threshold Tolerance

The IMP1834 independently monitors 5-volt and 3.3-volt power supplies. Users can independently select the 5-volt and 3.3-volt tolerance thresholds through two select pins. For a 3.3-volt supply, tolerance levels are 10 percent or 20 percent and for 5-volt systems, 5 percent or 10 percent. When an out-of-tolerance power supply voltage is detected, the proper reset output asserts and remains active for 350 milliseconds after the supply returns to an in-tolerance condition.

Manual Pushbutton Reset Input

A single debounced push button reset input is included. When pulled low by a mechanical switch, both 5-volt and 3.3-volt reset outputs are asserted and remain active for 350 milliseconds after the pushbutton is released.

Two Output Stage Configurations

The IMP1834 family consists of three devices. Like the IMP1834, the IMP1834D devices have a push-pull output stage but have active LOW reset signals. The IMP1834A differs from the IMP1834D by its open drain output structure.

Output Configuration Summary

 
       
 
IMP Part
Output Structure

RESET Polarity

IMP1834
Push-Pull
LOW
IMP1834A
Open-Drain
LOW
IMP1834D
Push-Pull
HIGH
 
       
    · Data Sheets  
   
  · IMP1834, IMP1834A, IMP1834D   
 
       
     
    IMP1233D and 1233M  
       
    The IMP1233D and IMP1233M are low cost, low power microprocessor supervisors. Maximum supply current is 20 microamperes at 5 volts or 15 microamperes at 3.6 volts. Compared to competitive devices available from Dallas Semiconductor, IMP1233D and IMP1233M devices offer over 60 percent lower supply current. Threshold voltages are available for 5-, 3.3- and 3-volt systems.

The IMP1233 devices have an open-drain output structure with an on-chip pull-up resistor. No external components are needed. An active-low reset signal is issued whenever the monitored supply voltage is below the reset threshold. After the supply voltage returns to an in-tolerance condition, the reset signal remains active for 350 milliseconds, allowing the power supply and system microprocessor to stabilize.

All devices operate over an operating temperature range of -40 degrees centigrade to +85 degrees centigrade.

 
       
    · Product Summary Table  
       
 
IMP Part
Reset Threshold

Maximum Supply Current

Package

IMP1233MS-55
4.625V
20 microamperes
8-pin, SO
IMP1233MS-5
4.375V
20 microamperes
8-pin, SO
IMP1233MS-3
2.720V
20 microamperes
8-pin, SO
IMP1233DZ-5
4.625V
20 microamperes
4-pin, SOT-223
IMP1233DZ-15
4.125V
20 microamperes
4-pin, SOT-223
IMP1233DZ-10
4.375V
20 microamperes
4-pin, SOT-223
 
       
    · Data Sheets  
   
  · IMP1233D   
  · IMP1233M   
 
       
     
    IMP690A, IMP692A, IMP802L/M, and IMP805L  
       
    · New Microprocessor Supervisors Offer 70% Lower Power at 50% Lower Price

The IMP690A, IMP692A, IMP802L, IMP802M, and IMP805L are pin-for-pin replacements for the similarly numbered devices from Maxim Integrated Products, with the addition of thermal and short-circuit protection while offering 70 percent lower operating power and 50 percent lower list pricing.
Using a 0.8 micron CMOS process, the new IMP supervisors integrate a battery backup switchover circuit and 20 ohm power switch, microprocessor/microcontroller watchdog function, microprocessor reset and power failure detection functions. In addition, the IMP designs add short-circuit protection and thermal protection to all members of the family. The new IMP supervisors are specified at 100 microamperes maximum supply current consumption, compared to the 350-microampere limit published by Maxim, a reduction of 70 percent in power usage.
 
       
    · Product Summary Table  
       
 
IMP Part No.
RESET Polarity

Threshold Voltage

Power Fail Threshold Accuracy

Watchdog Function

IMP690A
LOW
4.65V
4%
YES
IMP692A
LOW
4.40V
4%
YES
IMP802L
LOW
4.65V
2%
YES
IMP802M
LOW
4.40V
2%
YES
IMP805L
HIGH
4.40V
4%
YES
 
       
    · Data Sheets  
   
  · IMP690A, IMP692A, IMP802L, IMP802M, IMP805L   
 
       
     
    IMP706P/R/S/T/J, IMP708P/R/S/T/J  
       
    · 3/3.3/4V Microprocessor Supervisors with Power Fail Indicator and Improved Watchdog Timer

The IMP706P/R/S/T/J and IMP708R/S/T/J microprocessor supervisors are designed for 3.0-, 3.3- and 4.0-volt power supply rails. Compared to pin-compatible devices available from Maxim Integrated Products Integrated Products, the low reset threshold IMP706 and IMP708 microprocessor supervisors feature 30-percent lower supply current and include a 4-volt supply monitoring option. Maximum supply current is a low 140 microamperes. Another functional enhancement is that the internal watchdog timer can be disabled, an often needed capability during system development and debugging.

IMP Watchdog Function Enhanced

The IMP706 watchdog timer was improved by adding a disable function. It is often desirable to disable the watchdog timer during the system development phase or in troubleshooting a system in the field.
 
       
    Feature Summary  
 
IMP Part No.
RESET Polarity

Manual
RESET

Watchdog
Timer

Threshold
Voltage

IMP706P
LOW
YES
YES
2.63V
IMP706R/S/T/J
HIGH
YES
YES
2.63V/2.93V/3.08V/
4.0V
IMP708R/S/T/J
LOW and HIGH
YES
NO
2.63V/2.93V/3.08V/
4.0V
 
       
    · Data Sheets  
   
  · IMP706P, IMP706R/S/T/J, IMP708R/S/T/S/J   
 
       
     
    IMP705, IMP706, IMP707, IMP708, and IMP813L
Supervisors with Watchdog Timer and Power Fail Indicator
 
       
    · 60% Lower Supply Current than Maxim Devices
· MicroSO Package

The IMP705, IMP706, IMP707, IMP708, and IMP813L integrate power supply monitoring and microprocessor/microcontroller watchdog functions into compact 8-pin MicroSO packages. In addition, compared to pin-compatible devices available from Maxim Integrated Products, the IMP devices have reduced supply current requirements by 60 percent. Maximum supply current is a low 140 microamperes.
The new IMP supervisor family offers several functional options. Each device generates a reset signal during power-up, power-down and during brownout conditions. Designed to monitor a 5 volt power supply, 4.65 volt and 4.4 volt threshold devices are offered. A separate 1.25 volt threshold, power-fail detection circuit can check battery levels or non-5 volt supplies.

All devices have a manual reset input. The IMP705/706/813L feature a watchdog timer output that is set if the watchdog input is not triggered within 1.6 seconds.

The IMP813L has the same pin-out and functions as the IMP705 but has an active-HIGH reset output. The IMP707/IMP708 have both active-HIGH and active-LOW reset outputs instead of a watchdog function.

The IMP705, IMP706, and IMP813L supervisors monitor the power supply and battery in microprocessor and digital systems. A reset signal is generated whenever the supply voltage drops below 4.65 volts for the IMP705, IMP707 and IMP813L. The IMP706 and IMP708 generate a reset for supply voltages below 4.40 volts.

 
       
    · Product Summary Table  
       
 
IMP Part No.
RESET Polarity

Manual
RESET

Watchdog
Timer

Threshold
Voltage

IMP705
LOW
YES
YES
4.65V
IMP706
LOW
YES
YES
4.40V
IMP707
LOW and HIGH
YES
YES
4.65V
IMP708
LOW and HIGH
YES
YES
4.40V
IMP813
HIGH
YES
YES
4.65V
 
       
    · Data Sheets  
   
  · IMP705, IMP706, IMP707, IMP708, IMP 813L   
 
       
     
    IMP809, IMP810, IMP811, IMP812  
       
    · Low Power, Low Cost Microprocessor Supervisors
· 75% Lower Power Supply Current than Maxim

The IMP809, IMP810, IMP811 and IMP812 supervisors monitor the power supply of a microprocessor or microcontroller. A supervisor chip prevents the microprocessor or microcontroller from executing software instructions or enabling hardware incorrectly because of low power supply voltage. Each supervisor is available with six reset threshold options that range from 2.63V to 4.63 V with 1.5%, or better, accuracy.
 
       
    · Supervisor Selection Guide  
       
 
IMP809

IMP810

IMP811

IMP812

Package Pins
3
3
4
4
Package Type
SOT-23
SOT-23
SOT-143
SOT-143
Manual Reset
Active-HIGH RESET Output
 
Active-LOW RESET Output
 
 
 
       
    If the monitored power supply voltage drops below the chip-reset threshold, the supervisor generates a RESET signal to the microprocessor or microcontroller. The RESET signal is maintained active for a minimum time, 140 milliseconds, after the supply goes back above the reset threshold voltage. The IMP809 and IMP810 RESET output signals are opposite polarity. The IMP811 and IMP812 supervisors add a Manual Reset (MR) input for push-button RESET activation and also have opposite polarity RESET output signals.

The IMP supervisors were designed for low current consumption to support battery operated systems. Power supply current is 15 microamperes maximum for the 4.00V, 4.38V and 4.63V threshold devices that serve 5V systems and 10 microamperes maximum for the 2.63V, 2.93V and 3.08V threshold devices that are designed for 3V systems. Compared to the 4.63V threshold Maxim MAX809, the IMP809, manufactured on an advanced 0.8-micron analog CMOS process, reduces maximum unloaded supply current by 75%.

 
       
    · Data Sheets  
   
  · IMP809/810   
  · IMP811/812