MAX814/MAX815/MAX816
19-0412; Rev 1; 12/05
1% Accuracy, Low-Power, +3V and +5V
P Supervisory Circuits
_______________General Description ____________________________Features
The MAX814/MAX815/MAX816 are high-accuracy
1% Worst-Case Reset Threshold Accuracy
microprocessor (P) supervisory circuits that provide
4.8V, 4.7V, 4.55V, 3.03V, or Adjustable Reset
power-on reset, watchdog, and power-fail functions.
Thresholds
They eliminate manual trimming and improve reliability
1% Low-Line Threshold Accuracy (MAX814)
in critical applications needing high-accuracy reset
thresholds. The RESET output is guaranteed to be in 60mV Above Reset Threshold
the correct state for V down to 1V. The reset com-
CC
200ms Reset Time Delay
parator is designed to ignore fast transients on V .
CC
Active-Low RESET Output
Reset thresholds are available for operation with a vari-
Active-High RESET Output (MAX814/MAX816)
ety of 3V and 5V supply voltages.
75A Max Supply Current
A 75A maximum supply current makes the MAX814/
Guaranteed RESET Valid to V = 1V
MAX815/MAX816 ideal for use in portable equipment. All CC
three devices are available in 8-pin DIP and SO pack-
Manual Reset Input
ages. See the Selector Table for a review of features.
2% Power-Fail Comparator
Independent Watchdog with 1.56sec Timeout
_____________________Selector Table
(MAX815)
Power-Supply Glitch Immunity
FEATURE MAX814 MAX815 MAX816
8-Pin SO and DIP Packages
RESET Output
RESET Output
Manual Reset
______________Ordering Information
V Reset Voltage K, L, N, T K, L, N, T Adjustable
CC
PART* TEMP RANGE PIN-PACKAGE
Power-Fail Monitor
MAX814_CPA 0C to +70C 8 PDIP
Low-Line Detector
*The MAX814/MAX815 offer a choice of reset threshold voltages.
Watchdog Circuit
From the Reset Trip Threshold table, select the suffix corre-
sponding to the desired threshold and insert it into the blank to
complete the part number.
________________________Applications
Devices are available in both leaded and lead-free packaging.
Medical Equipment
Specify lead free by adding the + symbol at the end of the part
Controllers
number when ordering.
Intelligent Instruments
Critical P Power Monitoring
Ordering Information continued at end of data sheet.
Portable/Battery-Powered Equipment
Reset Trip Thresholds table appears at end of data sheet.
Set-Top Boxes
__________________________________________________________Pin Configurations
TOP VIEW
MR 1 8 RESET MR 1 8 WDO MR 1 8 RESET
2 7 RESET 2 7 RESET 2 7 RESET
V V V
CC CC CC
MAX814 MAX815 MAX816
GND 3 6 LOW LINE GND 3 6 WDI GND 3 6 RESET IN
PFI 4 5 PFO PFI 4 5 PFO PFI 4 5 PFO
DIP/SO DIP/SO DIP/SO
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxims website at www.maxim-ic.com.1% Accuracy, Low-Power, +3V and +5V
P Supervisory Circuits
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect GND) Operating Temperature Ranges
V ....................................................................-0.3V to +6.0V Commercial.........................................................0C to +70C
CC
All Other Pins (Note 1)........................... -0.3V to (V + 0.3V) Extended...........................................................-40C to +85C
CC
Terminal Current (PFI, RESET IN, MR)................................10mA Storage Temperature Range .............................-65C to +125C
Terminal Current (all other pins) .........................................20mA
Continuous Power Dissipation (T = +25C)
A
Plastic DIP (derate 9.09mW/C above +70C) ............727mW
SO (derate 5.88mW/C above +70C).........................471mW
Stresses beyond 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 beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS, +5V Parts (MAX814/MAX815K, L, N)
(V = 4.85V to 5.5V for MAX814K/MAX815K, V = 4.75V to 5.5V for MAX814L/MAX815L, V = 4.60V to 5.5V for MAX814N/
CC CC CC
MAX815N, T = T to T , unless otherwise noted.)
A MIN MAX
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
MAX814_C, MAX815_C 1.0 5.5
Operating Voltage Range V V
CC
MAX814_E, MAX815_E 1.2 5.5
MAX814_C, MAX815_C 75
Supply Current I A
SUPPLY
MAX814_E, MAX815_E 85
MAX814K, MAX815K 4.75 4.85
Reset Threshold V MAX814L, MAX815L 4.65 4.75 V
RT
MAX814N, MAX815N 4.50 4.60
Reset Threshold Hysteresis 0 mV
Reset Pulse Width t 140 200 250 ms
RS
V I = 800A V -1.5
OH SOURCE CC
RESET Output Voltage MAX814 V
V I = 3.2mA 0.4
OL SINK
V I = 800A V -1.5
OH SOURCE CC
I = 3.2mA 0.4
SINK
RESET, WDO, PFO, LOW LINE
V
Output Voltage
V MAX814_C/MAX815_C, V = 1.0V, I = 50A 0.3
OL CC SINK
MAX814_E/MAX815_E, V = 1.2V, I = 100A 0.3
CC SINK
Watchdog Timeout Period t MAX815 1.12 2.00 s
WD
WDI Pulse Width t MAX815 50 ns
WP
Low 0.8
WDI Input Threshold V MAX815, V = 5.0V V
WDI CC
High 2.4
WDI Input Current I WDI = V or WDI = 0V -1.0 1.0 A
WDI CC
MR to WDO High Delay t MAX815 (Note 1) 1 s
WDO
MAX814_C, V falling 50 70
LOW LINE to RESET Differential CC
V mV
LL
Threshold
MAX814_E, V falling 48 73
CC
MAX814K, V rising 4.93
CC
LOW LINE Threshold V MAX814L, V rising 4.83 V
LLT
CC
MAX814N, V rising 4.68
CC
2 _______________________________________________________________________________________
MAX814/MAX815/MAX816