CAT824SSDI-G [CATALYST]
System Supervisory Voltage Reset with Watchdog and Manual Reset; 系统监控电压复位与看门狗和手动复位
| 型号： | CAT824SSDI-G |
| 厂家： | 
CATALYST SEMICONDUCTOR |
| 描述： | System Supervisory Voltage Reset with Watchdog and Manual Reset |
| 文件： | 总14页 (文件大小：209K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
CAT823, CAT824, CAT825
System Supervisory Voltage Reset with
Watchdog and Manual Reset
FEATURES
DESCRIPTION
The CAT823, CAT824, and CAT825 provide basic
reset and monitoring functions for the electronic
systems. Each device monitors the system voltage
and maintains a reset output until that voltage reaches
the device’s specified trip value and then maintains
the reset output active condition until the device’s
internal timer, after a minimum timer of 140ms; to
allow the systems power supply to stabilize.
Automatically restarts microprocessor after
Power failure
Monitors pushbutton for external override
Accurate under voltage system monitoring
Brownout detection system reset for use with
3.0, 3.3, and 5.0 volt systems
Pin and function compatible with the
MAX823/24/25 products
The CAT823 and CAT824 also have a watchdog input
which can be used to monitor a system signal and
cause a reset to be issued if the signal fails to change
state prior to a timeout condition.
Operating Range from -40°C to +85°C
Available in TSOT-23 5-lead and SC-70 packages
For Ordering Information details, see page 13.
The CAT823 and CAT825 also provide a manual
reset input which can be used to initiate reset if pulled
low. This input can be directly attached to a push-
button or a processor signal.
APPLICATIONS
Microprocessor and Microcontroller based
systems
Intelligent Instruments
Control Systems
Critical µP Monitors
Portable Equipment
PIN FUNCTIONS
PIN CONFIGURATION
Pin Name Function
TSOT-23 5-Lead
SC-70 5-Lead
CMOS Push-Pull Active Low Reset
¯¯¯¯¯¯
RESET
Output
1
2
5
4
1
2
5
4
RESET
GND
VCC
WDI
RESET
GND
VCC
WDI
GND
Ground
Manual Reset input – Pulled high
Internally by a 52kΩ resistor designed
to be driven low by a mechanical
pushbutton, open drain output or CMOS
output.
CAT823
CAT824
¯¯¯
MR
3
3
MR
RESET
CMOS Push-Pull Active High Reset
Output
RESET
1
5
VCC
RESET
Watchdog Timer Input – Designed to be
driven by a processor output or can be
disabled by tri-stating or leaving open.
2
3
WDI
VCC
GND
CAT825
4
MR
RESET
Power Supply
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
BLOCK DIAGRAM
V
CC
TIMEOUT
COMPARATOR
LEVEL SENSE
&
WDI*
TIMER
RESET
V
CC
DIGITAL
DELAY
TOLERANCE
+
–
V
CC
BIAS
V
CC
V
CC
VOLTAGE
REFERENCE
RESET*
52kΩ
LEVEL SENSE
&
MR*
DEBOUNCE
* Functions Available by Device
¯¯¯¯¯¯
RESET
¯¯¯
MR
Device
RESET
WDI
CAT823
CAT824
CAT825
x
x
x
x
x
x
x
x
x
Doc. No. MD-3027, Rev. A
2
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
ABSOLUTE MAXIMUM RATINGS(1)
Parameters
Ratings
Units
V
Supply Voltage
6
All other pins
-0.3 to (VCC + 0.3)
V
Input Current, VCC
20
20
mA
mA
¯¯¯¯
Output Current RST, RST
Continuous Power Dissipations (TA = +70ºC)
SC-70 5-lead (derate 3.1mW/ºC above +70ºC)
TSOT-23 5-lead (derate 7.1mW/ºC above +70ºC)
Storage Temperature
247
571
mW
mW
ºC
-65 to 150
-40 to +85
+300
Operating Ambient Temperature
ºC
Lead Soldering (10 seconds max)
ºC
ESD Rating: Low Voltage Pins
Human Body Model
2000
200
V
V
Machine Model
RECOMMENDED OPERATING CONDITIONS
Parameter
Range
1.0 to 5.5
Units
V
VCC (TA = 0ºC to +70ºC)
VCC (TA = -40ºC to +85ºC)
All Other Pins
1.2 to 5.5
V
-0.1 to (VCC + 0.1)
-40 to +85
V
Ambient Temperature
ºC
Notes:
(1) Stresses above 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 outside of those listed in the operational sections of this
specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
ELECTRICAL OPERATING CHARACTERISTICS
DC Characteristics: VCC = 3.0V to 5.5V for L/M versions; VCC = 2.0V to 3.6V for the R/S/T/Y/Z version,
-40ºC ≤ TA ≤ +85ºC unless otherwise noted. Typical Values at TA = 25ºC and VCC = 5V for L/M versions;
VCC = 3.3V for the T/S versions; VCC = 3.0V for the R version; and VCC = 2.5V for the Y/Z versions.(1)
Symbol Parameter
Conditions
Min
Typ
Max
Units
CAT823 (L/M Versions)
CAT824 (L/M Versions)
6
17
µA
CAT823 (R/S/T/Y/Z Versions)
CAT824 (R/S/T/Y/Z Versions)
4
12
µA
ICC
Supply Current
CAT825 (L/M Versions)
3
2
8
6
µA
µA
V
CAT825 (R/S/T/Y/Z Versions)
CAT82_L at -40ºC ≤ TA ≤ +85ºC
CAT82_M at -40ºC ≤ TA ≤ +85ºC
CAT82_T at -40ºC ≤ TA ≤ +85ºC
CAT82_S at -40ºC ≤ TA ≤ +85ºC
CAT82_R at -40ºC ≤ TA ≤ +85ºC
CAT82_Z at -40ºC ≤ TA ≤ +85ºC
CAT82_Y at -40ºC ≤ TA ≤ +85ºC
4.50
4.25
3.00
2.85
2.55
2.25
2.13
4.63 4.75
4.38 4.50
3.08 3.15
2.93 3.00
2.63 2.70
2.32 2.38
2.19 2.25
V
V
VRST
Reset Threshold
V
V
V
V
Reset Threshold
Tempco
40
ppm/ºC
CAT82_L/M
10
5
mV
mV
µs
Reset Threshold
Hysteresis
CAT82_R/S/T/Y/Z
VCC to Reset Delay(2) VCC = VTH to (VTH - 100mV)
tRD
tRP
20
Reset Active
Timeout Period
140
200
400
ms
CAT82_L/M, VCC = VRST max
ISOURCE = -120µA
,
VCC - 1.5V
¯¯¯¯¯¯
Voltage
RESET Output High
VOH
CAT82_T/S/R/Z/Y, VCC = VRST max
ISOURCE = -30µA
,
0.8 x VCC
CAT82_L/M, VCC = VRST min
ISINK = 3.2mA
,
0.4
0.3
0.3
0.3
V
CAT82_T/S/R/Z/Y, VCC = VRST min
ISINK = 1.2mA
,
¯¯¯¯¯¯
Voltage
RESET Output Low
VOL
TA = 0ºC to +70ºC, VCC = 1V,
VCC falling, ISINK = 50µA
TA = TMIN to TMAX, VCC = 1.2V,
VCC falling, ISINK = 100µA
CAT82_L/M, Reset = 0V, VCC = 5.5V
CAT82_L/M, Reset = 0V, VCC = 3.6V
VCC > 1.8V, ISOURCE = -150µA
1.5
0.8
¯¯¯¯¯¯
Short-Circuit Current
RESET Output
ISOURCE
VOH
mA
V
0.8 x VCC
CAT824L/M & CAT825L/M,
VCC = VRST max, ISINK = 3.2mA
Reset Output
Voltage
0.4
0.3
VOL
CAT824R/S/T/Y/Z & CAT825R/S/T/Y/Z,
VCC = VRST max, ISINK = 1.2mA
Notes:
(1) Over-temperature limits are guaranteed by design and not production tested.
(2) The RESET short-circuit current is the maximum pull-up current when reset is driven low by a bidirectional output.
Doc. No. MD-3027 Rev. A
4
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
ELECTRICAL OPERATING CHARACTERISTICS (continued)
DC Characteristics: VCC = 3.0V to 5.5V for L/M versions; VCC = 2.0V to 3.6V for the R/S/T/Y/Z version,
-40ºC ≤ TA ≤ +85ºC unless otherwise noted. Typical Values at TA = 25ºC and VCC = 5V for L/M versions;
VCC = 3.3V for the T/S versions; VCC = 3.0V for the R version; and VCC = 2.5V for the Y/Z versions.
Symbol Parameter
Conditions
Min
Typ
Max
Units
WATCHDOG INPUT (CAT823 & CAT824)
tWD
tWDI
VIL
Watchdog Timeout Period
WDI Pulse Width
1.12
50
1.60
3.20
s
VIL = 0.4V, VIH = 0.8 x VCC
ns
0.3 x VCC
160
WDI Input Voltage(3)
V
VIH
0.7 x VCC
-20
WDI = VCC, Time Average
WDI = 0V, Time Average
120
-15
WDI Input Current(4)
µA
MANUAL RESET INPUT(CAT823 & CAT825)
VIL
0.3 x VCC
¯¯¯
V
MR Input Voltage
VIH
0.7 x VCC
1
¯¯¯
tPB
µs
µs
ns
kΩ
MR Pulse Width
¯¯¯
tPDLY
5
MR low to Reset Delay
¯¯¯
Pulse Width with No Reset
100
52
MR Noise Immunity
¯¯¯
35
75
MR Pullup Resistance (internal)
Notes:
(3) WDI is internally serviced within the watchdog period if WDI is left open.
(4) The WDI input current is specified as an average input current when the WDI input is driven high or low. The WDI input if connected to a
three-stated output device can be disabled in the tristate mode as long as the leakage current is less than 10µA and a maximum
capacitance of less than 200pF. To clock the WDI input in the active mode the drive device must be able to source or sink at least 200µA
when active.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
TYPICAL ELECTRICAL OPERATING CHARACTERISTICS TABLES
Normalized Reset Threshold
Voltage vs. Temperature
VCC Supply Current vs. Temperature
9
8
7
6
5
4
3
2
1
1.06
1.04
1.02
1.00
0.98
0.96
0.94
-40 -20
0
20
40
60
80 100
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
TEM PERATURE (ºC)
Doc. No. MD-3027 Rev. A
6
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
FUNCTIONAL DESCRIPTION
PROCESSOR RESET
MANUAL RESET
The CAT823-825 detect supply voltage (VCC)
conditions that are below the specified voltage trip
value (VRST) and provide a reset output to maintain
The CAT823 and CAT825 each have a Manual Reset
¯¯¯
(MR) input to allow for alternative control of the reset
¯¯¯
outputs. The MR input is designed for direct con-
¯¯¯¯¯¯
¯¯¯
correct system operation. On power-up, RESET (and
nection to a pushbutton (see Figure 1). The MR input
RESET if available) are kept active for a minimum
delay tRP of 140ms after the supply voltage (VCC) rises
above VRST to allow the power supply and processor
to stabilize. When VCC drops below the voltage trip
is internally pulled up by 52kΩ resistor and must be
pulled low to cause the reset outputs to go active.
Internally, this input is debounced and timed such that
¯¯¯¯¯¯
RESET (and RESET) signals of at least 140ms
¯¯¯¯¯¯
value (VRST), the reset output signals RESET (and
minimum will be generated. The min 140ms tRP delay
commences as the Manual Reset input is released
from the low level. (see Figure 2)
¯¯¯¯¯¯
RESET) are pulled active. RESET (and RESET if
available) is specifically designed to provide the reset
input signals for processors. This provides reliable
and consistent operation as power is turned on, off or
during brownout conditions by maintaining the
processor operation in known conditions.
Figure 1. Pushbutton RESET
MR
RESET
GND
Supply
Voltage
CAT825
V
CC
RESET
Figure 2. Timing Diagram – Pushbutton RESET
t
PB
MR
t
PDLY
V
IH
V
IL
t
RP
RESET
RESET
V
V
OH
OL
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
7
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
WATCHDOG TIMER
The CAT823 and CAT824 provide a Watchdog input
reliable is a dedicated I/O output transitioned by a
specific software instruction.
¯¯¯¯¯¯
(WDI). The watchdog timer function forces RESET
(and RESET in the CAT824) signals active when the
WDI input does not have a transition from low-to-high
or high-to-low within 1.12 seconds. Timeout of the
The watchdog can be disabled by floating (or tri-
stating) the WDI input (see Figure 4). If the watchdog
is disabled the WDI pin will be pulled low for the first
7/8th’s of the watchdog period (tWD) and pulled high for
the last 1/8th of the watchdog period. This pulling low
of the WDI input and then high is used to detect an
open or tri-state condition and will continue to repeat
until the WDI input is driven high or low.
¯¯¯¯¯¯
watchdog starts when RESET (RESET on the
CAT824) becomes inactive. If a transition occurs on
the WDI input pin prior to the watchdog time-out, the
watchdog timer is reset and begins to time-out again.
If the watchdog timer is allowed to time-out, then the
reset output(s) will go active for tRP and once released
will repeat the watchdog timeout process.
For most efficient operation of devices with the
watchdog function the WDI input should be held low
the majority of the time and only strobed high as
required to reset the watchdog timer.
Figure 3 below shows a typical implementation of a
watchdog function. Any processor signal that repeats
dependant on the normal operation of the processor
or directed by the software operating on the processor
can be used to strobe the watchdog input. The most
Figure 3. Watchdog Timer
WDI
MR
PIC
µC
Supply
Voltage
GND
RESET
DECODER
ADDRESS
CAT823
V
CC
MCLR
Figure 4. Watchdog Disable Circuit
V
Tristate
CC
V
CC
RESET
GND
150kΩ
110kΩ
CAT823
µC
OUTPUT
MR
WDI
Doc. No. MD-3027 Rev. A
8
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
Figure 5. Timing Diagram – Strobe Input
INVALID
STROBE
VALID
STROBE
INDETERMINATE
STROBE
WDI
MIN.
t
WD
MAX.
RESET
Figure 6. Timing Diagram – Power Down
V
CC
V
RST
(MAX)
V
RST
V
(MIN)
RST
t
RD
RESET
V
OH
RESET Slews with V
CC
V
OL
RESET (CAT824 & CAT825)
Figure 7. Timing Diagram – Power Up
V
RST
(MAX)
V
RST
V
RST
(MIN)
V
CC
t
RP
RESET
V
OH
V
OL
RESET (CAT824 & CAT825)
RESET
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
9
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
APPLICATION NOTES
OUTPUT VALID CONDITIONS
¯¯¯¯¯¯
µP’s with Bidirectional Reset Pins
The RESET output uses a push-pull output which can
maintain a valid output down to a VCC of 1.0 volts. To
sink current below 0.8V a resistor can be connected
¯¯¯¯¯¯
The RESET output can be pulled low by processors
like the 68HC11 allowing for a system reset issued by
the processor. The maximum pullup current that can
be sourced by the CAT82_L/M is 1.5mA (and by the
CAT82_T/R/S/Z/Y is 800µA) allowing the processor to
pull the output low even when the CAT82x is pulling it
high.
¯¯¯¯¯¯
from RESET to Ground (see Figure 8.)
arrangement will maintain a valid value on the RESET
output during both power up and down but will draw
This
¯¯¯¯¯¯
¯¯¯¯¯¯
current when the RESET output is in the high state. A
resistor value of about 100kΩ should be adequate in
most situations to maintain a low condition valid
output down to VCC equal to 0V.
Power Transients
Generally short duration negative-going transients of
less than 2µs on the power supply at VRST minimum
will not cause a reset condition. However the lower
the voltage of the transient the shorter the required
time to cause a reset output. These issues can
usually be remedied by the proper location of bypass
capacitance on the circuit board.
¯¯¯¯¯¯
Figure 8. RESET Valid to 0 Volts VCC
WDI
MR
100kΩ
GND
CAT823
µC
RESET
V
CC
RESET
Doc. No. MD-3027 Rev. A
10
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
PACKAGE OUTLINE DRAWING
TSOT-23 5-Lead (TD)(1)(2)
SYMBOL
MIN
NOM
MAX
1.00
0.10
0.90
0.45
0.20
D
A
A1
A2
b
e
0.01
0.80
0.30
0.12
0.05
0.87
c
0.15
D
2.90 BSC
2.80 BSC
1.60 BSC
0.95TYP
0.40
E1
E
E
E1
e
L
0.30
0º
0.50
8º
L1
L2
θ
0.60 REF
0.25 BSC
TOP VIEW
A2 A
A1
θ
L
b
c
L2
L1
SIDE VIEW
END VIEW
For current Tape and Reel information, download the PDF file from:
http://www.catsemi.com/documents/tapeandreel.pdf.
Notes:
(1) All dimensions in millimeters. Angles in degrees.
(2) Complies with JEDEC MO-193.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-3027, Rev. A
CAT823, CAT824, CAT825
SC-70 5-Lead (SD)(1)(2)
SYMBOL
MIN
NOM
MAX
1.10
0.10
1.00
0.30
0.18
2.20
2.40
1.35
D
A
A1
A2
b
0.80
0.00
0.80
0.15
0.10
1.80
1.80
1.15
e
e
c
D
2.00
2.10
E1
E
E
E1
e
1.25
0.65 BSC
0.36
L
0.26
0.46
L1
L2
θ
0.42 REF
0.15 BSC
TOP VIEW
0°
4°
8°
θ1
10°
θ1
A2
A1
A
θ
L
L1
b
θ1
c
L2
SIDE VIEW
END VIEW
For current Tape and Reel information, download the PDF file from:
http://www.catsemi.com/documents/tapeandreel.pdf.
Notes:
(1) All dimensions in millimeters. Angles in degrees.
(2) Complies with JEDEC MO-203.
Doc. No. MD-3027 Rev. A
12
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT823, CAT824, CAT825
EXAMPLE OF ORDERING INFORMATION(1)
Prefix
Device #
Suffix
CAT
823
L
TD
I
-G
T3
Package
TD: TSOT-23 5-Lead
SD: SC-70 5-Lead
Lead Finish
G:NiPdAu
Tape & Reel
T: Tape & Reel
3: 3000/Reel
Product
Number
823
Optional
Company ID
824
825
Reset Threshold
Voltage
Temperature Range
I = Industrial (-40ºC to 85ºC)
L: 4.63V
M: 4.38V
T: 3.08V
S: 2.93V
R: 2.63V
Z: 2.32V
Y: 2.19V
TOP MARKING INFORMATION (For all Thresholds)
NiPdAu Finish (-G)
Device #
CAT823
CAT824
CAT825
Package
TSOT-23
Top Marking
SC-70
SC-70
SC-70
RG
TB
TD
TSOT-23
TSOT-23
ORDERING PART NUMBER
CAT823LTDI-G
CAT823MTDI-G CAT824MTDI-G(4)
CAT824LTDI-G(4)
CAT825LTDI-G
CAT825MTDI-G
CAT825TTDI-G
CAT825STDI-G
CAT825RTDI-G
CAT825ZTDI-G
CAT825YTDI-G
CAT825LSDI-G
CAT825MSDI-G
CAT825TSDI-G
CAT825SDI-G
CAT825RSDI-G
CAT825ZSDI-G
CAT825YSDI-G
CAT823TTDI-G
CAT823STDI-G
CAT824TTDI-G(4)
CAT824TSDI-G(4)
CAT823RTDI-G CAT824RTDI-G(4)
CAT823ZTDI-G
CAT823YTDI-G
CAT823LSDI-G
CAT824ZTDI-G(4)
CAT824YTDI-G(4)
CAT824LSDI-G(4)
CAT823MSDI-G CAT824MSDI-G(4)
CAT823TSDI-G
CAT824TSDI-G(4)
CAT823SSDI-G CAT824SSDI-G(4)
CAT823RSDI-G CAT824RSDI-G(4)
CAT823ZSDI-G
CAT824ZSDI-G(4)
CAT823YSDI-G CAT824YSDI-G(4)
Notes:
(1) All packages are RoHS-compliant (Lead-free, Halogen-free).
(2) The standard lead finish is NiPdAu.
(3) This device used in the above example is a CAT823LTDI -GT3 (4.63V, TSOT-23 5-Lead, Industrial Temperature, NiPdAu, Tape & Reel)
(4) Contact factory for package availability.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
13
Doc. No. MD-3027, Rev. A
REVISION HISTORY
Date
Rev. Reason
Initial Release
09/10/2007
A
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Document No: MD-3027
Revision:
A
Issue date:
09/10/07
相关型号：
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