DS1831A/T&R [DALLAS]
Power Supply Management Circuit, Fixed, 4 Channel, PDIP16, 0.300 INCH, DIP-16;
| 型号： | DS1831A/T&R |
| 厂家： | 
DALLAS SEMICONDUCTOR |
| 描述： | Power Supply Management Circuit, Fixed, 4 Channel, PDIP16, 0.300 INCH, DIP-16 光电二极管 |
| 文件： | 总14页 (文件大小：74K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
DS1831/A/B
Multi-Supply Micromonitor
www.dalsemi.com
FEATURES
PIN ASSIGNMENT
ꢀ 5 volt power-on reset
DS1831
ꢀ 3.3 (or 3) volt power-on reset
ꢀ 2 referenced comparators with separate
outputs for monitoring additional supplies
ꢀ Internal power is drawn from higher of either
the IN5V input or the IN3.3V input
ꢀ Excellent for systems designed to operate
with multiple power supplies.
ꢀ Asserts resets during power transients
IN5V
RST5V
TOL5V
TD5V
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
IN3.3V
RST3.3V
TOL3.3V
TD3.3V
PBRST5V
IN1
PBRST3.3V
NMI1
ꢀ Pushbutton reset input for system override
ꢀ Maintains reset for user configurable times
IN2
NMI2
of 10ms, 100ms, or 1 sec
GND
MPBRST
ꢀ Watchdog timer for software monitoring
16-PIN (300 MIL) DIP
&
(DS1831A)
16-PIN (150 MIL) SOIC
ꢀ Precision temperature-compensated voltage
reference and voltage sensor
DS1831A
ꢀ 16 pin DIP & 16 pin 150mil SOIC available
ꢀ Operating Temperature of -40°C to +85°C
IN1
ST
6
7
8
11
10
9
NMI1
WDS
TDWD
GND
DS1831B
TD5V
PBRST5V
IN1
4
5
6
13
12
11
TD3.3V
PBST
NMI1
DESCRIPTION
The DS1831 Multi-Supply Monitor & Reset monitors up to 4 system voltages: 5 volt supply, 3.3 (or 3)
volt supply, and 2 additional user configurable voltage monitors. DS1831 power for internal operation
comes from the higher voltage level of the 3.3 volt input or the 5 volt input. One of these inputs must be
greater than 1 volt for device operation. Pushbutton (manual reset) functionality is provided for the 5 volt
reset, the 3.3 volt reset or for all reset outputs by the master pushbutton. The DS1831A replaces one
reference comparator and the master pushbutton with watchdog and the DS1831B replaces the 3.3V
PBRST with a last reset status output.
1 of 14
031400
DS1831/A/B
TOL and TD inputs allow user configuration of the DS1831 for multiple applications. The TOL inputs
configure the tolerance for the specified output and the TD inputs configure the reset time delays.
PIN CONFIGURATION
1
IN5V
5V Power Supply Input
9
MPBRST
TDWD
Master Pushbutton (DS1831)
Watchdog Time Delay Select (DS1831A)
Non Maskable Interrupt 2 (DS1831)
2
5V Reset Open Drain Output
10
RST 5V
NM12
Watchdog Status Output (DS1831A)
Non Maskable Interrupt 1
WDS
3
4
TOL5V
TD5V
Selects 5V Input Tolerance
Selects 5V Reset Time Delay
11
12
NM11
3.3V Reset Pushbutton
PBRST3.3V
PBST
Pushbutton Status Output (DS1831B)
Select 3.3V Reset Time Delay
5V Reset Pushbutton
Sense Input 1
13 TD3.3V
5
6
7
PBRST5V
IN1
14 TOL3.3V
Selects 3.3V Input Tolerance
3.3V Reset Open Drain Output
IN2
Sense Input 2 (DS1831)
Watchdog Strobe Inputs
(DS1831A)
15
RST 3.3V
ST
8
GND
Ground
16 IN3.3V
3.3V Power Supply Input
BLOCK DIAGRAM Figure 1
IN5V
100KΩ
PBRST5V
TD5V
VCC
TOL5V
TOLERANCE
BIAS
+
-
RST5V
TIME
DELAY
1.25V T.C.
REFERENCE
100KΩ
Level Sense
&
Debounce
MPBRST
IN3.3V
100KΩ
PBRST3.3V
TD3.3V
VCC
TOLERANCE
BIAS
TOL3.3V
RST3 3V
TIME
DELAY
+
-
-
NMI1
NMI2
IN1
+
-
IN2
+
GROUND
2 of 14
DS1831/A/B
OPERATION – POWER MONITOR
The DS1831 provides the functions of detecting out-of-tolerance conditions on a 3.3 (or 3) volt and 5 volt
power supply and warning a processor based system of impending power failure. When an input is
detected as out-of-tolerance on either voltage input the RST for that supply will be forced active low.
When that input returns to a valid state the associated RST will remain active for the time delay selected
with the associated TD input and then return to an inactive state until the next input out-of-tolerance
condition.
On power-up both resets are kept active for the selected reset time after the associated power supply input
has reached the selected tolerance. This allows the power supply and system power to stabilize before
RST is released.
All internal operating current for the DS1831 will be supplied by either the IN3.3V or IN5V input which
ever has the highest voltage level.
OPERATION - TOLERANCE SELECT
The DS1831 provides 2 TOL inputs for individual customization of the DS1831 to specific application
requirements. If the TOL for the 5 volt supply is tied to the 5 volt input a 5% tolerance is selected. If the
TOL is connected to ground a 10% tolerance is selected or if it is left unconnected a 15% tolerance is
selected. If the TOL for the 3.3 volt supply is tied to the 3.3 volt input a 5% tolerance is selected, a 10%
tolerance is selected if it is connected to ground, and a 20% tolerance is selected if the input is left
unconnected. These tolerance conditions are set at power up and can only be changed by power cycling
the device.
OPERATION - RESET TIME-DELAY SELECT
The DS1831 provides 2 TD inputs for individual customization of reset time-delays and an additional one
for the DS1831A watchdog. TD inputs select time delays for the IN5V and IN3.3V resets outputs and the
Watchdog on the DS1831A. The reset time delays are shown in table 1. These allow the selection of
minimum delays of 10ms, 100ms, and 1000ms.
Wiring an individual reset output to the push-button input of the other voltage reset allows custom reset
timings or allows for the sequencing of the reset outputs. See figure 2.
These time-delays are set at power-up and cannot be changed after the device reaches an in-tolerance
condition.
TD INPUTS/RESET AND WATCHDOG TIME-DELAYS Table 1
RESET TIME-DELAY
TD
GND
Float
VCC
MIN
10 ms
100 ms
1000 ms
TYP
16 ms
160 ms
1600 ms
MAX
20 ms
200 ms
2000 ms
3 of 14
DS1831/A/B
PUSHBUTTON RESET SEQUENCING Figure 2
3.3V Supply
5V Supply
IN3.3V
IN5V
1
2
3
16
RST5V
TOL5V
*
RST3.3V
15
14
DS1831
TOL3.3V
TD5V
TD3.3V
4
5
13
12
PBRST5V
PBRST3.3V
GND
*NOTE:
The RST 5V output is connected to the IN3.3V via a 100KΩ resistor in the push-button input and therefore
does not require a pull-up resistor (an addition pull up can be used to accelerate responses.) If an external
pull up is used in this example it must be connected to the 3.3 volt power supply.
OPERATION - PUSHBUTTON RESET
The DS1831 provides 3 pushbutton inputs for manual reset of the device. Pushbutton inputs for the 3.3V
reset, 5v reset, and a master pushbutton reset (DS1831 & DS1831B only) input; provide multiple options
for system control. The 3.3 volt pushbutton reset and 5 volt pushbutton resets provide a simple manual
reset for the associated reset output; while the master pushbutton reset forces all resets and NMI outputs
active low.
The 5 volt reset pushbutton input and the 3.3 volt reset pushbutton input provide manual reset control
input for each associated reset output. When the output associated with a pushbutton input is not active, a
pushbutton reset can be generated by pulling the associated PBRST pin low for at least 20 µs. When the
pushbutton is held low the reset will be forced active and will remain active for a reset cycle after the
pushbutton is released. See figure 2 for an application example that allows a user to sequence the reset
outputs.
A master pushbutton reset cycle can be started if at least one voltage input (IN5V, IN3.3V, IN1, or IN2) is in
tolerance and at least 1 output is active. A master pushbutton reset is generated by pulling the MPBRST
pin low for at least 20 µs. When the pushbutton is held low all outputs are forced active and will remain
active for a reset or NMI time delay after the pushbutton is released. The Master Pushbutton input is
pulled high through an internal 100KΩ pull up resistor and debounced via internal circuitry. See figure 3
for an application example. Figures 4 and 5 for the timing diagram.
The 5V and 3.3V pushbutton reset inputs are pulled high through an internal 100KΩ pull up resistor to
the voltage input, which is associated with that pushbutton. The master pushbutton is pulled to the greater
of the “IN5V” and “IN3.3V” inputs.
*Caution should be exercised to avoid pulling the pushbutton inputs above associated supply inputs.
Generally all pushbutton inputs should be driven low with open drain inputs.
4 of 14
DS1831/A/B
PUSHBUTTON RESET Figure 3
5V Supply
IN5V
1
2
3
10KΩ
RST5V
TOL5V
DS1831
TD5V
4
5
PBRST5V
GND
TIMING DIAGRAM – MASTER PUSHBUTTON RESET Figure 4
tPB
MPBRST
tPDLY
VIH
VIL
tRST
RST5V and RST3.3V
VOH
NMI1 and NMI2
tNMI
VOH
5 of 14
DS1831/A/B
TIMING DIAGRAM – 5V OR 3.3V PUSHBUTTON RESET Figure 5
tPB
tPDLY
VIH
PBRST5V
(or PBRST3.3V
)
VIL
tRST
RST5V (or RST3.3V
)
VOH
VIL
OPERATION – PUSHBUTTON STATUS
The DS1831B provides a master pushbutton status open drain output. The PBST output indicates the
status of the most recent reset condition. If the last reset was generated by the master pushbutton input it
would maintain a low condition until cleared by another event (except the master pushbutton) generating
a reset. Once cleared it will remain high until the master pushbutton is pulled low generating a reset
condition. The PBST output is open drain and will require a pull-up resistor on the output to maintain a
valid condition. The value of the pull up resistor is not critical in most cases but must be set low enough
to pull the output to a high state. A common value used is 10KΩs (See Figure 6).
DS1831B APPLICATION EXAMPLE Figure 6
5V Supply
3.3V Supply
VCC
IN5V
IN3.3V
1
2
3
4
5
6
7
8
16
15
14
13
10K
RST5V
RST3.3V
VCC
TOL5V
VSENSE1
VSENSE2
TOL3.3V
TD5V
TD3.3V
PBST
10KΩ
DS1831B
PBRST5V
12
11
10
9
IN1
IN2
NMI1
NMI2
GND
MPBRST
6 of 14
DS1831/A/B
OUTPUT VALID CONDITIONS
The DS1831 can maintain valid outputs as long as one input remains above 1.0 volt. Accurate voltage
monitoring additionally requires that either the 3.3V IN or 5V IN input be above 1.5 volts. If this
condition is not met and at least one of the supply inputs are at or above 1.0 volt all outputs are
maintained in the active condition. The DS1831 requires pull-up resistors on the outputs to maintain a
valid output. The value of the pull up resistor is not critical in most cases but must be set low enough to
pull the output to a high state. A common pull-up resistor value used is 10KΩs (See Figure 7).
APPLICATION DIAGRAM - OPEN DRAIN OUTPUTS Figure 7
3.3V Supply
5V Supply
IN5V
IN3.3v
1
2
3
16
10KΩ
10KΩ
RST3.3V
RST5V
15
14
DS1831
TOL5V
TD5V
TOL3.3V
TD3.3V
4
5
13
12
PBRST5V
PBRST3.3V
GND
NOTE:
If outputs are at different voltages the outputs can not be connected to form a wired AND.
OPERATION - NON-MASKABLE INTERRUPT
The DS1831 has 2 referenced comparator (DS1831A has only 1 referenced comparator) that can be used
to monitor upstream voltages or other system specific voltages. Each comparator is referenced to the 1.25
volt internal band gap reference and controls an open drain output. When a voltage being monitored
decays to the voltage sense point, the DS1831 pulses the NMI output to the active state for a minimum 10
µs. The comparator detection circuitry also has built-in hysteresis of 100µV. The supply must be below
the voltage sense point for approximately 2 µs before a low NMI will be generated. In this way, power
supply noise is minimized in the monitoring function, reducing false interrupts. See Figure 8 for the
Non-maskable timing diagram.
Versatile trip voltages can be configured by the use of an external resistor divider to divide the voltage at
a sense point to the 1.25 volt trip levels of the referenced comparators. See figure 9 for an example
circuit diagram and sample equations. The equations demonstrate a design process to determine the
resistor values to use.
Connecting one or both NMI outputs to one of the reset specific PBRST ’s allows the non-maskable
interrupt to generate an automatic reset for the reset time period when an out-of-tolerance condition
occurs in a monitored supply. An example is shown in Figure 9.
The output associated with the specific input will be held low if the voltage on the input pin is less than
1.25 volts. If the voltage is above 1.25 volts the output will not sink current and will be pulled up by the
required pull up resistor. The value of the resistors is not critical in most cases but must be set low
enough to pull the output to a high state. A common value used is 10KΩs. If a NMI output is connected
7 of 14
DS1831/A/B
to a pushbutton input an additional pull-up resistor can be used (to improve speed of transitions) but is not
required.
During a power-up, any detected IN pin levels above VTP by the comparator are disabled from generating
an inactive (high) interrupt until at least 1 supply on the VIN inputs rises above 1.5 volts. All NMI outputs
will be held active (low) until at least one VIN reaches 1.5 volts at which point the NMI outputs will be
based on the value of the associated IN input.
VIN >1.25 V
VTP(max)
VTP(max)
VTP
VTP
VTP(min)
VTP(min)
tNMI
NMI
tIPD
VOH
VOL
TIMING DIAGRAM - NON MASKABLE INTERRUPT Figure 8
8 of 14
DS1831/A/B
NON MASKABLE INTERRUPT CIRCUIT EXAMPLE Figure 9
VSENSE1
VSENSE2
VCC
R1
R2
PBRST3.3V
NMI1
PBRST5V
IN1
10KΩ
R3
DS1831
IN2
NMI2
R4
GND
MPBRST
R1+ R2
Example:
Therefore:
VSENSE1 = 11.50 volts trip point
VSENSE1
=
X 1.25V
R2
R1+100KΩ
11.50V =
X 1.25V
100KΩ
Resulting In: R1 = 820KΩ
Repeat the same steps to solve for R3 and R4 with VSENSE2
.
OPERATION - WATCHDOG TIMER
The watchdog timer function (DS1831A only) forces the WDS signal active (low) when the ST input
does not have a transition (high-to-low or low-to-high) within the predetermined time period. The time-
out period is determined by the condition of the TDWD pin. If TDWD is connected to ground the minimum
watchdog time-out would be 10 ms, TD floating would yield a minimum time-out of 100 ms, and TDWD
connected to VCC would provide a time-out of 1000 ms minimum. Time-out of the watchdog starts when
at least one of the RST outputs becomes inactive (high). If a transition occurs on the ST input pin prior to
time-out, the watchdog timer is reset and begins to time-out again. If the watchdog timer is allowed to
time-out, then the WDS output is pulsed active for a minimum of 100µs.
The WDS output is an open-drain output and must be pulled up externally. In most applications this
output would be connected to one of the Pushbutton inputs and would not require an external pull-up
resistor. The value of the resistors is not critical in most cases but must be set low enough to pull the
output to a high state. A common value used is 10KΩs. If a WDS output is connected to a pushbutton
input an additional pull-up resistor can be used (to improve speed of transitions) but is not required.
The ST input can be derived from many microprocessor outputs. The most typical signals used are the
microprocessor address signals, data signals, or control signals. When the microprocessor functions
normally, these signals would, as a matter of routine, cause the watchdog to be reset prior to time-out. To
guarantee that the watchdog timer does not time-out, a transition must occur at or less than the minimum
9 of 14
DS1831/A/B
times shown in Table 1. A typical circuit example is shown in Figure 10. The watchdog timing is shown
in Figure 11.
The DS1831A watchdog function cannot be disabled. The watchdog strobe input must be strobed to avoid
a watchdog time-out however the watchdog status output can be disconnected yielding the same result.
WATCHDOG CIRCUIT EXAMPLE Figure 10
VSENSE1
VCC
R1
R2
PBRST3.3V
NMI1
PBRST5V
IN1
10KΩ
DS1831
µP
WDS
ST
TDWD
GND
TIMING DIAGRAM-STROBE INPUT Figure 11
INVALID
EDGES
VALID
EDGES
INDETERMINATE
EDGES
ST
MIN.
tST
MAX.
tTD
WDS
10 of 14
DS1831/A/B
RESET TIMING DIAGRAM - POWER UP Figure 12
tR
VINTP (MAX)
VINTP
VINTP (MIN)
IN5V (or IN3.3V
)
tRPU
VOH
RST5V (or RST3.3V
)
RESET TIMING DIAGRAM - POWER DOWN Figure 13
tF
IN5V (or IN3.3V
)
VINTP (MAX)
VINTP
VINTP (MIN)
tRPD
RST5V (or RST3.3V
)
VOL
11 of 14
DS1831/A/B
ABSOLUTE MAXIMUM RATINGS*
Voltage on IN5V or IN3.3V
Pins Relative to Ground
Voltage on either RST Relative to Ground
-0.5V to +7.0V
-0.5V to the greater of IN5V + 0.5V or IN3.3V + 0.5V
Voltage on PBRST 3.3V Relative to Ground -0.5V to IN3.3V + 0.5V
Voltage on PBRST 5V Relative to Ground
Voltage on MPBRST Relative to Ground
Operating Temperature
-0.5V to 5V IN + 0.5V
-0.5V to the greater of IN5V + 0.5V or IN3.3V + 0.5V
-40°C to +85°C
Storage Temperature
-55°C to +125°C
Soldering Temperature
+260°C for 10 sec.
* This is a stress rating only and functional operation of the device at these or any other conditions
above those indicated in the operation sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods of time may affect reliability.
** The voltage input on IN and ST inputs can be exceeded if the input current is less than 10mA.
RECOMMENDED DC OPERATING CONDITIONS
(-40° to 85°C)
PARAMETER
SYMBOL
V IN
MIN
1.0
MAX
5.5
UNITS NOTES
IN5V (Supply Voltage)
IN3.3V (Supply Voltage)
ST and MPBRST input
High Level
V
V
V
V
V
V
1
1
V IN
1.0
5.5
2
1,2*
1,3*
1
VIH
VINT + 0.3
VINT-0.4
VIH
VIH
2
2
IN3.3V + 0.3
IN5V +0.3
PBRST 3.3V input High Level
PBRST 5V input High Level
1
ST, PBRST 3.3V, PBRST 5V and
MPBRST input Low Level
VIL
-0.3
.05
V
1
* VINT is the greater voltage level of the IN5V or IN3.3V
.
DC ELECTRICAL CHARACTERISTICS
(-40° to 85°C, VCC = 1.0V TO 5.5V)
PARAMETER
SYMBOL
IIL
MIN
TYP
MAX UNITS NOTES
Input Leakage
-1.0
+10
+1.0
4
5
6
7
8
1
1
1
1
1
1
1
µA
Output Current @ 2.4V
Output Current @ 0.4V
IOH
IOL
mA
µA
µA
V
ICC
80
100
80
Operating Current @ 5.5V
Operating Current @ 3.6V
IN5V Trip Point (TOL5V = IN5V)
IN5V Trip Point (TOL5V = GND)
IN5V Trip Point (TOL5V = Float)
IN3.3V Trip Point (TOL3.3V = IN3.3V
ICC
60
VINTP
VINTP
VINTP
VINTP
VINTP
VINTP
VTP
4.50
4.25
4.00
2.98
2.80
2.47
1.20
4.63
4.38
4.15
3.06
2.88
2.55
1.25
4.75
4.49
4.24
3.15
2.97
2.64
1.30
V
V
V
)
IN3.3V Trip Point (TOL3.3V = GND)
IN3.3V Trip Point (TOL3.3V = Float)
IN Input Trip Points
V
V
V
12 of 14
DS1831/A/B
(tA = 25°C)
NOTES
CAPACITANCE
PARAMETER
Input Capacitance
Input Capacitance
SYMBOL
CIN
MAX
UNITS
pF
5
7
COUT
pF
AC ELECTRICAL CHARACTERISTICS
(-40° to 85°C, VCC = 1.0V TO 5.5V)
PARAMETER
SYMBOL MIN
TYP
16
MAX
20
UNITS NOTES
RESET Active Time (TD=Low)
RESET Active Time (TD=Float)
RESET Active Time (TD=High)
VCC Detect to RST
tRST
tRST
tRST
tRPU
tRPD
tIPD
tNMI
tPB
10
ms
ms
ms
ms
µs
8
8
8
8
9
9
100
160
1600
200
1000
2000
See RESET Active Time
2
2
10
10
VCC Detect to RST
VIN Detect to NMI
µs
NMI Active Time
20
20
µs
PBRST = VIL
µs
PBRST Stable Low to Reset
Active
tPDLY
50
µs
Watchdog Timeout (TD(WD)=Low)
Watchdog Timeout (TDWD=Float)
Watchdog Timeout (TDWD=High)
ST Pulse Width
tTD
tTD
tTD
tST
10
100
1000
10
16
20
ms
ms
ms
ns
160
200
1600
2000
Vin Slew Rate (V INTP(MAX) to V
tF
300
0
µs
)
INTP(MIN)
Vin Slew Rate (V INTP(MAX) to V
tR
ns
)
INTP(MIN)
NOTES:
1. All voltages are referenced to ground.
2. Measured with both IN3.3V & IN5V ≥ 2.7V.
3. Measured with both IN3.3V & IN5V ≤ 2.7V.
4. All Pushbutton inputs are internally pulled to the associated Supply IN input or the greatest Supply IN
input for the MPBRST with an internal Impedance of 100KΩ.
5. All outputs are Open Drain and output IOH would be determined by the external pull-up resistor.
6. Measured with outputs open and IN3.3V or IN5V ≤ 5.5V
7. Measured with outputs open and IN3.3V or IN5V ≤ 3.6 volts.
8. Measured using tR = 5µs
9. Noise immunity - pulses <2 µs at a trip level will not cause a RST or NMI .
13 of 14
DS1831/A/B
Ordering Information
Ordering Part
Number
Package Type
Description
DS1831
16 Pin DIP 300mil
16 Pin SO 150mil
16 Pin DIP 300mil
16 Pin SO 150mil
16 Pin DIP 300mil
16 Pin SO 150mil
5v/3.3v MultiSupply Monitor
DS1831S
DS1831A
DS1831AS
DS1831B
DS1831BS
5v/3.3v MultiSupply Monitor
5v/3.3v MultiSupply Monitor w/Watchdog
5v/3.3v MultiSupply Monitor w/Watchdog
5v/3.3v MultiSupply Monitor w/Pushbutton Status
5v/3.3v MultiSupply Monitor w/Pushbutton Status
* Add “/T&R” for tape and reeling of surface mount packages.
14 of 14
相关型号：
DS1831AS+T&R
Power Supply Management Circuit, Fixed, 4 Channel, PDSO16, 0.150 INCH, ROHS COMPLIANT, SOIC-16
MAXIM
DS1831B/T&R
Power Supply Support Circuit, Fixed, 4 Channel, PDIP16, 0.300 INCH, PLASTIC, DIP-16
MAXIM
©2020 ICPDF网 联系我们和版权申明