and active-low push-pull outputs. The reset outputs are
asserted and held when the supply voltage falls below the
factory-programmed threshold voltage, when the /MR pin
is pulled low, or if the watchdog times out. Reset is
asserted for the reset timeout delay after the supply
voltage increases above the rising threshold voltage or
when manual reset input is asserted high.
The MAX823/4/5 features an integrated pull-up resistor on
the /MR pin. An active-low push-pull reset output (/RESET)
and an active-high reset output (RESET) provide flexibility
when interfacing with various microcontrollers, PMICs, or
load switches. The watchdog input can be left
unconnected for applications that do not require watchdog
monitoring.
The MAX823/4/5 consumes a quiescent current of only
3.8µA and is offered in standard SOT23-5 and SC70-5
packages. It is rated for the –40°C to +125°C temperature
range.
Datasheets and support documentation are available on
Micrel’s website at:
www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
Precision 1.665V to 4.625V power supply monitor
±0.5% threshold accuracy at T
A
= +25°C
±1.5% threshold accuracy from T
A
= –40°C to +125°C
3.8µA supply current (S,R,T,W,Y,Z options)
4.8µA supply current (L,M options)
Manual reset input (MAX823/5)
140ms (min.) reset timeout period
1.6s (typ.) watchdog timeout period
Active-high and active-low push-pull outputs
Guaranteed reset output valid to V
CC
= 1V
−40°C
to +125°C junction temperature range
5-pin SOT23 and SC70 packages
8x lower watchdog input current than competition
Applications
•
•
•
•
•
•
Computers and controllers
Embedded controllers
Intelligent instruments
Automotive systems
Critical µP monitoring
Portable/battery-powered equipment
Typical Application
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 •
http://www.micrel.com
February 26, 2015
Revision 2.0
Micrel, Inc.
Table 1. Part Functionality Guide
Function
Active-Low Reset
Active-High Reset
Watchdog Input
Manual Reset Input
MAX823
Yes
No
Yes
Yes
MAX824
Yes
Yes
Yes
No
MAX823/4/5
MAX825
Yes
Yes
No
Yes
Ordering Information
(1)
Top Marking
Option
Suffix
Reset
Threshold
MAX823
EUK
(SOT23-5)
X3L
X3M
X3T
X3S
X3R
X3Z
X3Y
X3W
(2)
MAX824
(2)
MAX825
(2)
Temp. Range
(2)
EXK
(SC70-5)
XA
XB
XC
XE
XF
XJ
XK
XL
EUK
(SOT23-5)
X4L
X4M
X4T
X4S
X4R
X4Z
X4Y
X4W
(2)
EXK
(SC70-5)
4Y
YA
YB
YC
YD
YE
YF
YG
EUK
(SOT23-5)
X5L
X5M
X5T
X5S
X5R
X5Z
X5Y
X5W
(2)
EXK
(SC70-5)
YH
YI
YJ
YK
YO
YR
YS
YT
–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
Lead
Finish
L
M
T
S
R
Z
Y
W
Note:
4.625V
4.375V
3.075V
2.925V
2.625V
2.315V
2.188V
1.665V
Pb-Free
Pb-Free
Pb-Free
Pb-Free
Pb-Free
Pb-Free
Pb-Free
Pb-Free
1. Insert the desired option suffix (based on the desired reset threshold) into the blank to complete the part number. All reset options are available in
both SOT23 and SC70 Pb-Free packages. Standard ship format is in tape and reel only. There is a 3,000 piece minimum order increment for
production reel. Reel diameter is 7 inches, hub diameter is 2 inches, and width is 8mm.
2. -5 indicates a 5-pin package.
Part Number Convention
February 26, 2015
2
Revision 2.0
Micrel, Inc.
MAX823/4/5
Pin Configuration
MAX823
SOT23(EUK) & SC70(EXK)
Top View
MAX824
SOT23(EUK) & SC70(EXK)
Top View
MAX825
SOT23(EUK) & SC70(EXK)
Top View
Pin Description
Pin Number
MAX823
Pin Number
MAX824
Pin Number
MAX825
Pin Name
Pin Function
Active-Low Reset Output. Pulses low for 200ms when triggered, and
remains low whenever V
CC
is below the reset threshold or when /MR is
a logic low. It remains low for 200ms after one of the following occurs:
V
CC
rises above the reset threshold, the watchdog triggers a reset, or
/MR goes low to high.
Ground.
Active-High Reset Output. Pulses high for 200ms when triggered, and
remains high whenever V
CC
is below the reset threshold or when /MR
is a logic low. It remains high for 200ms after one of the following
occurs: V
CC
rises above the reset threshold, the watchdog triggers a
reset, or /MR goes low to high. RESET is the inverse of /RESET.
Watchdog Input. If WDI remains either high or low for longer than the
watchdog timeout period, the internal watchdog timer runs out and a
reset is triggered. The internal watchdog timer clears whenever reset
is asserted, or whenever WDI sees a rising or falling edge. If WDI is
left unconnected or is connected to a three-stated buffer output, the
watchdog feature is disabled.
Manual Reset Input. A logic low on /MR asserts reset. Reset remains
asserted as long as /MR is held low and for 200ms after /MR returns
high. The active-low input has an internal 52kΩ pull-up resistor. It can
be driven from a CMOS logic line or shorted to ground with a switch.
Leave open or connect to VCC if unused.
Supply Voltage Pin. VCC is the input to the supply voltage monitor.
When the supply voltage falls below the reset threshold voltage, reset
outputs (/RESET and RESET) are triggered immediately. When the
supply voltage rises above the reset threshold plus hysteresis voltage,
the reset outputs remain asserted for the duration of the reset timeout
period. An optional 0.1µF bypass capacitor mounted close to VCC
provides additional transient immunity.
1
1
1
/RESET
2
2
2
GND
-
3
3
RESET
4
4
-
WDI
3
-
4
/MR
5
5
5
VCC
February 26, 2015
3
Revision 2.0
Micrel, Inc.
MAX823/4/5
Absolute Maximum Ratings
(3)
Supply Voltage (V
CC
) ....................................
−0.3V
to
+6.0V
/MR, WDI, RESET, /RESET..................
−0.3V
to V
CC
+0.3V
Input Current (All Pins except RESET, /RESET) ........ 20mA
Output Current (RESET, /RESET) .............................. 20mA
Junction Temperature (T
J
) ........................
−40°C
to +150°C
Storage Temperature (Ts).........................
−65°C
to +150°C
(5)
ESD Rating (Human Body Model)(MAX823/4/5) ........ 3kV
Operating Ratings
(4)
Supply Voltage (V
CC
) .................................... +1.0V to +5.5V
Watchdog Input (WDI)........................................... 0V to V
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