MAX16997AAUA+ Maxim Integrated Products, MAX16997AAUA+ Datasheet

IC TIMER WATCHDOG 8-UMAX

MAX16997AAUA+

Manufacturer Part Number
MAX16997AAUA+
Description
IC TIMER WATCHDOG 8-UMAX
Manufacturer
Maxim Integrated Products
Type
Watchdog Circuitr
Datasheet

Specifications of MAX16997AAUA+

Number Of Voltages Monitored
1
Output
Open Drain or Open Collector
Reset
Active Low
Reset Timeout
Adjustable/Selectable
Voltage - Threshold
Adjustable/Selectable
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
Mounting Style
SMD/SMT
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
The MAX16997/MAX16998 are microprocessor (µP)
supervisory circuits for high-input-voltage and low-qui-
escent-current applications. These devices detect
downstream circuit failures and provide switchover to
redundant circuitry. See the Selector Guide for the dif-
ferent versions of this product family.
The MAX16997/MAX16998 family has four independent
inputs for reset and watchdog functions. SWT and SRT
inputs independently set the timeout periods of watch-
dog and reset timers through external capacitors.
RESETIN/EN monitor voltages at respective inputs. A
resistive voltage-divider sets the reset threshold.
The MAX16998A/B/D generate two output signals,
RESET and ENABLE. RESET asserts whenever
RESETIN drops below its threshold voltage or when the
watchdog timer detects a timing fault at WDI. Once
asserted, and after all reset conditions are removed,
RESET remains low for the reset timeout period, t
and then goes high. The MAX16997A generates one
output signal (ENABLE) based on the voltage level at
EN and the signal at WDI.
The MAX16997A does not have a RESET output. The
watchdog is disabled if the voltage at EN is below its
threshold. The MAX16997A watchdog timer starts tim-
ing when the voltage at EN becomes higher than the
preset threshold voltage level. Each time EN rises
above the preset threshold voltage, the initial watchdog
timeout period is 8 times the normal watchdog timeout
period (t
The MAX16997/MAX16998 are available in 8-pin lead-
free µMAX
-40°C to +125°C automotive temperature range.
19-4000; Rev 2; 8/09
Pin Configurations appear at end of data sheet.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Automotive
Industrial
MAX16997A
MAX16998A
MAX16998B
MAX16998D
PART
WP
®
).
packages and are fully specified over the
________________________________________________________________ Maxim Integrated Products
WINDOW SIZE (%)
WATCHDOG
General Description
100
100
50
75
High-Voltage Watchdog Timers with
Applications
ENABLE
RESET
Adjustable Timeout Delay
,
o Wide 5V to 40V Input Voltage Range
o 18µA Quiescent Current (Typical at +125°C)
o Capacitor-Adjustable Timeout Period for
o Windowed Watchdog Timer Options
o External Voltage Monitoring (RESETIN for the
o Car Battery-Compatible EN Input
o TTL- and CMOS-Compatible Open-Drain Outputs
o 18V Maximum Open-Drain Reset Output Voltage
o 28V Maximum Open-Drain Enable Output Voltage
o Power-On/Power-Off Reset Functionality
o AEC-Q100 Qualified
o -40°C to +125°C Operating Temperature Range
o Small (3mm x 3mm) µMAX Package
o WDI Narrow Pulse Immunity
+Denotes a lead(Pb)-free/RoHS-compliant package.
/V Denotes Automotive qualified part.
MAX16997AAUA+
MAX16997AAUA/V+
MAX16998AAUA+
MAX16998AAUA/V+
MAX16998BAUA+
MAX16998BAUA/V+
MAX16998DAUA+
MAX16998DAUA/V+
Watchdog and Reset
(MAX16998B/D)
MAX16998A/B/D and EN for the MAX16997A)
(MAX16998A/B/D Only)
RESET
PART
Ordering Information
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
TEMP RANGE
EN
Selector Guide
Features
PIN-PACKAGE
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
RESETIN
1

Related parts for MAX16997AAUA+

MAX16997AAUA+ Summary of contents

Page 1

... Maximum Open-Drain Enable Output Voltage o Power-On/Power-Off Reset Functionality (MAX16998A/B/D Only) o AEC-Q100 Qualified , RESET o -40°C to +125°C Operating Temperature Range o Small (3mm x 3mm) µMAX Package o WDI Narrow Pulse Immunity PART MAX16997AAUA+ MAX16997AAUA/V+ MAX16998AAUA+ MAX16998AAUA/V+ MAX16998BAUA+ MAX16998BAUA/V+ MAX16998DAUA+ Applications MAX16998DAUA/V+ +Denotes a lead(Pb)-free/RoHS-compliant package. ...

Page 2

High-Voltage Watchdog Timers with Adjustable Timeout Delay ABSOLUTE MAXIMUM RATINGS (All pins referenced to GND, unless otherwise noted.) IN, ENABLE ............................................................-0.3V to +45V WDI, RESET, EN .....................................................-0.3V to +20V RESETIN .................................................................-0.3V to +20V SRT, SWT................................................................-0.3V to +12V Maximum Current (all ...

Page 3

High-Voltage Watchdog Timers with ELECTRICAL CHARACTERISTICS (continued 14V -40°C to +125°C, unless otherwise noted. Typical values are PARAMETER SYMBOL WATCHDOG TIMER WDI Input Threshold WDI Input Hysteresis WDI WDI ...

Page 4

High-Voltage Watchdog Timers with Adjustable Timeout Delay ( 1500pF +25°C, unless otherwise noted.) SWT SRT A SUPPLY CURRENT vs. TEMPERATURE 20.0 RESET AND ENABLE NOT 19.5 ASSERTED 19.0 18.5 18.0 17.5 17.0 16.5 16.0 15.5 ...

Page 5

High-Voltage Watchdog Timers with PIN NAME MAX16997A MAX16998A/B — — N. SWT 5 5 GND 6 6 WDI ENABLE 8 8 — 2 RESETIN — 3 SRT RESET — 7 _______________________________________________________________________________________ Adjustable ...

Page 6

High-Voltage Watchdog Timers with Adjustable Timeout Delay IN PREG RESETIN (MAX16998) EN (MAX16997) WDI BUFFER I RAMP SRT (MAX16998) I RAMP SWT GND 6 _______________________________________________________________________________________ MAX16997/MAX16998 Functional Diagram RESET ENABLE MAX16997A/ MAX16998A/B/D LOGIC ...

Page 7

High-Voltage Watchdog Timers with PON INITIAL WDI ENABLE t = WATCHDOG TIMEOUT PERIOD INITIAL 3 CONSECUTIVE t WITHOUT TRIGGER ENABLE GOES LOW WP Figure 1. MAX16997A Timing Diagram ...

Page 8

High-Voltage Watchdog Timers with Adjustable Timeout Delay V RESETIN V PON RESET OW WDI WDI t WP RESET ENABLE t = RESET TIMEOUT PERIOD RESET 3 CONSECUTIVE RESETS ENABLE GOES ACTIVE LOW Figure 3. MAX16998B/D Timing Diagram ...

Page 9

High-Voltage Watchdog Timers with Detailed Description The MAX16997/MAX16998 are µP supervisory circuits for high-input-voltage and low-quiescent-current appli- cations. These devices improve system reliability by monitoring the sub-system for software code execution errors. The MAX16997A/MAX16998A/B/D detect down- stream circuit failures, and ...

Page 10

High-Voltage Watchdog Timers with Adjustable Timeout Delay 1. RESETIN V PON t RESET RESET ENABLE ≤ t ≤ WDI WDI t WDI WDI WDI WDI t t ...

Page 11

High-Voltage Watchdog Timers with RESETIN Input (MAX16998A/B/D) The MAX16998A/B/D monitor the voltage at RESETIN using an adjustable reset threshold, set with an external resistive divider (see Figure 7). RESET asserts when V is below 1.235V. RESETIN Use the following equations ...

Page 12

High-Voltage Watchdog Timers with Adjustable Timeout Delay WDI falling edge occurs within the watchdog timeout period (t ) and is considered a late fault that asserts WP RESET. In case 3, the WDI falling edge occurs within the open window ...

Page 13

High-Voltage Watchdog Timers with Interfacing to Other Voltages for Logic Compatibility As shown in Figure 9, the open-drain RESET output can operate in the 2.5V to 18V range. This allows the device to interface a µP with other logic levels. ...

Page 14

High-Voltage Watchdog Timers with Adjustable Timeout Delay V BATT SRT RESETIN R2 SWT Figure 11. MAX16998A/B/D Switch Over to Backup Circuitry V BATT V CC MAX16997A SWT Figure 12. MAX16997A Application Diagram 14 ______________________________________________________________________________________ ...

Page 15

High-Voltage Watchdog Timers with TOP VIEW + MAX16997A N.C. 3 SWT 4 µMAX Chip Information PROCESS: BiCMOS ______________________________________________________________________________________ Adjustable Timeout Delay IN 8 ENABLE RESETIN 7 N.C. SRT 6 WDI SWT 5 GND For the latest ...

Page 16

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 16 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products ...

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