LM2984T/NOPB [TI]
1-CHANNEL POWER SUPPLY SUPPORT CKT, PZFM11;
| 型号： | LM2984T/NOPB |
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TEXAS INSTRUMENTS |
| 描述： | 1-CHANNEL POWER SUPPLY SUPPORT CKT, PZFM11 局域网 |
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LM2984
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SNVS098C –APRIL 1998–REVISED MARCH 2013
LM2984 Microprocessor Power Supply System
Check for Samples: LM2984
1
FEATURES
DESCRIPTION
The LM2984 positive voltage regulator features three
independent and tracking outputs capable of
delivering the power for logic circuits, peripheral
2
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Three Low Dropout Tracking Regulators
Output Current in Excess of 500 mA
Fully Specified for −40°C to +125°C Operation
Low Quiescent Current Standby Regulator
Microprocessor Malfunction RESET Flag
Delayed RESET on Power-Up
sensors and standby memory in
a
typical
microprocessor system. The LM2984 includes
circuitry which monitors both its own high-current
output and also an external μP. If any error conditions
are sensed in either, a reset error flag is set and
maintained until the malfunction terminates. Since
these functions are included in the same package
with the three regulators, a great saving in board
space can be realized in the typical microprocessor
system. The LM2984 also features very low dropout
voltages on each of its three regulator outputs (0.6V
at the rated output current). Furthermore, the
quiescent current can be reduced to 1 mA in the
standby mode.
Accurate pretrimmed 5V outputs
Reverse Battery Protection
Overvoltage Protection
Reverse Transient Protection
Short Circuit Protection
Internal Thermal Overload Protection
ON/OFF Switch for High Current Outputs
P+ Product Enhancement Tested
Designed also for vehicular applications, the LM2984
and all regulated circuitry are protected from reverse
battery installations or 2-battery jumps. Familiar
regulator features such as short circuit and thermal
overload protection are also provided. Fixed outputs
of 5V are available in the plastic TO-220 power
package.
Typical Application Circuit
COUT must be at least 10 μF to maintain stability. May be increased without bound to maintain regulation during
transients. Locate as close as possible to the regulator. This capacitor must be rated over the same operating
temperature range as the regulator. The equivalent series resistance (ESR) of this capacitor is critical; see curves.
Figure 1. Package Number NDJ0011B
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 1998–2013, Texas Instruments Incorporated
LM2984
SNVS098C –APRIL 1998–REVISED MARCH 2013
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These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
(1)(2)
Absolute Maximum Ratings
Input Voltage
Survival Voltage (<100 ms)
Operational Voltage
60V
26V
Internal Power Dissipation
Operating Temperature Range (TA)
Internally Limited
−40°C to +125°C
Maximum Junction Temperature
(3)
150°C
Storage Temperature Range
Lead Temperature
−65°C to +150°C
(Soldering, 10 sec.)
230°C
2000V
(4)
ESD Susceptability
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications do not
apply when operating the device beyond its specified operating ratings.
(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and
specifications.
(3) Thermal resistance without a heatsink for junction-to-case temperature is 3°C/W. Thermal resistance case-to-ambient is 40°C/W.
(4) Human body model, 100 pF capacitor discharged through a 1500Ω resistor.
Electrical Characteristics
VIN = 14V, IOUT = 5 mA, COUT = 10 μF, unless otherwise indicated. Boldface type refers to limits over the entire operating
(1)
temperature range, −40°C ≤ TA ≤ +125°C, all other limits are for TA = Tj = 25°C
.
Parameter
Conditions
Typical
Limit
Units
(2)
VOUT (Pin 11)
Output Voltage
5 mA ≤ IO ≤ 500 mA
5.00
4.85/4.75
5.15/5.25
25/25
Vmin
Vmax
6V ≤ VIN ≤ 26V
9V ≤ VIN ≤ 16V
7V ≤ VIN ≤ 26V
5 mA ≤ IOUT ≤ 500 mA
250 mAdc and 10 mArms
fo = 120 Hz
Line Regulation
2
5
mVmax
mVmax
mVmax
mΩ
50/50
Load Regulation
12
24
50/50
Output Impedance
,
Quiescent Current
IOUT = 500 mA
38
14
100/100
50/50
mAmax
mAmax
μV
IOUT = 250 mA
Output Noise Voltage
Long Term Stability
Ripple Rejection
10 Hz–100 kHz, IOUT = 100 mA
100
20
mV/1000 hr
dBmin
Vmax
fo = 120 Hz
70
60/50
0.80/1.1
0.50/0.70
0.75/0.60
26/26
Dropout Voltage
IOUT = 500 mA
IOUT = 250 mA
0.53
0.28
0.92
32
Vmax
Current Limit
Amin
Maximum Operational
Input Voltage
Continuous DC
Vmin
Maximum Line Transient
Reverse Polarity
Input Voltage DC
V
OUT ≤ 6V, ROUT = 100Ω, T ≤ 100 ms
OUT ≥ −0.6V, ROUT = 100Ω
65
60/60
Vmin
Vmin
V
−30
−15/−15
Reverse Polarity Input
Voltage Transient
T ≤ 100 ms, ROUT = 100Ω
−55
−35/−35
Vmin
(1) To ensure constant junction temperature, low duty cycle pulse testing is used.
(2) Tested Limits are ensured and 100% production tested.
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Electrical Characteristics (continued)
VIN = 14V, IOUT = 5 mA, COUT = 10 μF, unless otherwise indicated. Boldface type refers to limits over the entire operating
temperature range, −40°C ≤ TA ≤ +125°C, all other limits are for TA = Tj = 25°C (1)
.
Parameter
Conditions
Typical
Limit
Units
(2)
Vbuffer (Pin 10)
Output Voltage
5 mA ≤ IO ≤ 100 mA
5.00
4.85/4.75
5.15/5.25
25/25
Vmin
Vmax
6V ≤ VIN ≤ 26V
9V ≤ VIN ≤ 16V
7V ≤ VIN ≤ 26V
5 mA ≤ Ibuf ≤ 100 mA
50 mAdc and 10 mArms
fO = 120 Hz
Line Regulation
2
5
mVmax
mVmax
mVmax
mΩ
50/50
Load Regulation
15
200
50/50
Output Impedance
,
Quiescent Current
Output Noise Voltage
Long Term Stability
Ripple Rejection
Dropout Voltage
Current Limit
Ibuf = 100 mA
8.0
100
20
15/15
mAmax
μV
10 Hz–100 kHz, IOUT = 100 mA
mV/1000 hr
dBmin
fo = 120 Hz
70
60/50
0.50/0.80
0.15/0.15
26/26
Ibuf = 100 mA
0.35
0.23
32
Vmax
Amin
Maximum Operational
Input Voltage
Continuous DC
Vmin
Maximum Line
V
buf ≤ 6V, Rbuf = 100Ω,
T ≤ 100 ms
buf ≥ −0.6V, Rbuf = 100Ω
65
60/60
Vmin
Vmin
Vmin
Transient
Reverse Polarity
Input Voltage DC
Reverse Polarity Input
Voltage Transient
Vstandby (Pin 9)
Output Voltage
V
−30
−55
−15/−15
−35/−35
T ≤ 100 ms, Rbuf = 100Ω
1 mA ≤ IO ≤ 7.5 mA
6V ≤ VIN ≤ 26V
5.00
4.85/4.75
5.15/5.25
25/25
Vmin
Vmax
Line Regulation
9V ≤ VIN ≤ 16V
2
5
mVmax
mVmax
mVmax
Ω
7V ≤ VIN ≤ 26V
50/50
Load Regulation
Output Impedance
Quiescent Current
0.5 mA ≤ IOUT ≤ 7.5 mA
5 mAdc and 1 mArms, fo = 120 Hz
Istby = 7.5 mA
6
50/50
0.9
1.2
0.9
100
20
2.0/4.0
1.5/4.0
mAmax
mAmax
μV
Istby = 2 mA
Output Noise Voltage
Long Term Stability
Ripple Rejection
10 Hz–100 kHz, Istby = 1 mA
mV/1000 hr
dBmin
Vmax
fo = 120 Hz
Istby = 1 mA
Istby = 7.5 mA
70
60/50
0.50/0.60
0.60/0.70
12/12
Dropout Voltage
0.26
0.38
15
Vmax
Current Limit
mAmin
Vmin
Maximum Operational
Input Voltage
4.5V ≤ Vstby ≤ 6V,
Rstby = 1000Ω
65
60/60
Maximum Line
Transient
V
stby ≤ 6V, T ≤ 100 ms,
Rstby = 1000Ω
stby ≥ −0.6V,
Rstby = 1000Ω
65
60/60
Vmin
Reverse Polarity
Input Voltage DC
V
−30
−15/−15
Vmin
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Electrical Characteristics (continued)
VIN = 14V, IOUT = 5 mA, COUT = 10 μF, unless otherwise indicated. Boldface type refers to limits over the entire operating
temperature range, −40°C ≤ TA ≤ +125°C, all other limits are for TA = Tj = 25°C (1)
.
Parameter
Conditions
Typical
Limit
Units
(2)
Reverse Polarity Input
Voltage Transient
Tracking and Isolation
Tracking
T ≤ 100 ms, Rstby = 1000Ω
−55
−35/−35
Vmin
I
OUT ≤ 500 mA, Ibuf = 5 mA,
stby ≤ 7.5 mA
±30
±30
±100/±100
±100/±100
±100/±100
mVmax
mVmax
mVmax
VOUT–Vstby
I
Tracking
IOUT = 5 mA, Ibuf ≤ 100 mA,
Vbuf–Vstby
Istby ≤ 7.5 mA
Tracking
IOUT ≤ 500 mA, Ibuf ≤ 100 mA,
±30
VOUT–Vbuf
Istby = 1 mA
(3)
Isolation
ROUT = 1Ω, Ibuf ≤ 100 mA
5.00
5.00
5.00
5.00
4.50/4.50
5.50/5.50
4.50/4.50
5.50/5.50
4.50/4.50
5.50/5.50
4.50/4.50
5.50/5.50
Vmin
Vmax
Vmin
Vmax
Vmin
Vmax
Vmin
Vmax
Vbuf from VOUT
(3)
Isolation
ROUT = 1Ω, Istby ≤ 7.5 mA
Rbuf = 1Ω, IOUT ≤ 500 mA
Rbuf = 1Ω, Istby ≤ 7.5 mA
Vstby from VOUT
(3)
Isolation
VOUT from Vbuf
(3)
Isolation
Vstby from Vbuf
Computer Monitor/Reset Functions
Ireset Low
Vreset Low
Rt voltage
VIN = 4V, Vrst = 0.4V
5
2/0.50
0.40/0.40
1.15/0.75
1.30/2.00
45/17.0
mAmin
Vmax
VIN = 4V, Irst = 1 mA
(Pin 2)
0.10
1.22
1.22
50
Vmin
Vmax
Power On Reset
Delay
VμPmon = 5V
msmin
msmax
mVmin
mVmax
mVmin
mVmax
μAmax
(Tdly = 1.2 Rt Ct)
(4)
50
55/80.0
ΔVOUT Low
−350
−225/−175
−500/−550
225/175
750/800
1/5.0
Reset Threshold
ΔVOUT High
(4)
600
Reset Threshold
Reset Output
Leakage
VμPmon = 5V, Vrst = 12V
0.01
μPmon Input Current (Pin 4)
VμPmon = 2.4V
VμPmon = 0.4V
7.5
0.01
1.22
1.22
50
25/25
10/15
μAmax
μAmax
Vmin
μPmon Input
0.80/0.80
2.00/2.00
45/30
Threshold Voltage
μP Monitor Reset
Oscillator Period
μP Monitor Reset
Oscillator Pulse Width
Minimum μP Monitor
Input Pulse Width
Vmax
VμPmon = 0V
msmin
msmax
msmin
msmax
μs
(Twindow = 0.82 RtCmon
)
50
55/70
VμPmon = 0V
1.0
1.0
2
0.7/0.4
1.3/2.10
(RESETpw = 2000 Cmon
(5)
)
(3) Isolation refers to the ability of the specified output to remain within the tested limits when the other output is shorted to ground.
(4) Internal comparators detect when the main regulator output (VOUT) changes from the measured output voltage (with VIN = 14V) by the
specified amount, ΔVOUT High or ΔVOUT Low, and set the Reset Error Flag low. The Reset Error Flag is held low until VOUT returns to
regulation. The Reset Error Flag is then allowed to go high again after a delay set by Rtand Ct. (see Application Hints section).
(5) This parameter is a measure of how short a pulse can be detected at the μP Monitor Input. This parameter is primarily influenced by the
value of Cmon. (See Application Hints Section.)
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Electrical Characteristics (continued)
VIN = 14V, IOUT = 5 mA, COUT = 10 μF, unless otherwise indicated. Boldface type refers to limits over the entire operating
temperature range, −40°C ≤ TA ≤ +125°C, all other limits are for TA = Tj = 25°C (1)
.
Parameter
Conditions
Typical
Limit
Units
(2)
Reset Fall Time
Rrst = 10k, Vrst = 5V, Crst ≤ 10 pF
Rrst = 10k, Vrst = 5V, Crst ≤ 10 pF
VON = 2.4V
0.20
0.60
7.5
1.00/1.00
1.00/1.50
25/25
μsmax
μsmax
μAmax
μAmax
Vmin
Reset Rise Time
On/Off Switch Input
Current (Pin 8)
VON = 0.4V
0.01
1.22
1.22
10/10
On/Off Switch Input
Threshold Voltage
0.80/0.80
2.00/2.00
Vmax
BLOCK DIAGRAM
Pin Descriptions
Pin No.
Pin Name
Comments
1
2
VIN
Positive supply input voltage
Rt
Sets internal timing currents
Sets power-up reset delay timing
Microcomputer monitor input
Sets μC monitor timing
3
Ct
4
μPmon
Cmon
5
6
Ground
Reset
Regulator ground
7
Reset error flag output
8
ON/OFF
Vstandby
Vbuffer
Enables/disables high current regulators
Standby regulator output (7.5 mA)
Buffer regulator output (100 mA)
Main regulator output (500 mA)
9
10
11
VOUT
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External Components
Component
Typical Value
1 μF
Component Range
0.47 μF–10 μF
24k–510k
Comments
Required if device is located far from power supply filter.
Sets internal timing currents.
CIN
Rt
130k
Ct
0.33 μF
0.01 μF
10k
0.033 μF–3.3 μF
0.001 μF–0.1 μF
1k–100k
Sets power-up reset delay.
Ctc
Rtc
Establishes time constant of AC coupled computer monitor.
Establishes time constant of AC coupled computer monitor. (See Application Hints
section.)
Cmon
Rrst
Cstby
Cbuf
0.47 μF
10k
0.047 μF–4.7 μF
5k–100k
Sets time window for computer monitor. Also determines period and pulse width of
computer malfunction reset. (See Application Hints section.)
Load for open collector reset output. Determined by computer reset input
requirements.
10 μF
10 μF
10 μF
10 μF–no bound
10 μF–no bound
10 μF–no bound
A 10 μF is required for stability but larger values can be used to maintain
regulation during transient conditions.
A 10 μF is required for stability but larger values can be used to maintain
regulation during transient conditions.
COUT
A 10 μF is required for stability but larger values can be used to maintain
regulation during transient conditions.
Typical Circuit Waveforms
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Connection Diagram
Figure 2. Package Number NDJ0011B
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Typical Performance Characteristics
Dropout Voltage (VOUT
)
Dropout Voltage (Vbuf)
Figure 3.
Figure 4.
Dropout Voltage (Vstby
)
Dropout Voltage (VOUT)
Figure 5.
Figure 6.
Dropout Voltage (Vbuf
)
Dropout Voltage (Vstby)
Figure 7.
Figure 8.
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Typical Performance Characteristics (continued)
Peak Output Current (VOUT
)
Peak Output Current (Vbuf)
Figure 9.
Figure 10.
Peak Output Current (Vstby
)
Quiescent Current (VOUT)
Figure 11.
Figure 12.
Quiescent Current (Vbuf
)
Quiescent Current (Vstby)
Figure 13.
Figure 14.
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Typical Performance Characteristics (continued)
Quiescent Current (VOUT
)
Quiescent Current (Vbuf)
Figure 15.
Figure 16.
Quiescent Current (Vstby
)
Quiescent Current (VOUT)
Figure 17.
Figure 18.
Quiescent Current (Vbuf
)
Quiescent Current (Vstby)
Figure 19.
Figure 20.
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Typical Performance Characteristics (continued)
Output Voltage (VOUT
)
Output Voltage (Vbuf)
Figure 21.
Figure 22.
Output Voltage (Vstby
)
Low Voltage Behavior (VOUT)
Figure 23.
Figure 24.
Low Voltage Behavior (Vbuf
)
Low Voltage Behavior (Vstby)
Figure 25.
Figure 26.
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Typical Performance Characteristics (continued)
Line Transient
Response (VOUT
Line Transient
Response (Vbuf)
)
Figure 27.
Figure 28.
Line Transient
Response (Vstby
Load Transient
Response (VOUT)
)
Figure 29.
Figure 30.
Load Transient
Load Transient
Response (Vstby)
Response (Vbuf
)
Figure 31.
Figure 32.
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Typical Performance Characteristics (continued)
Output Impedance (VOUT
)
Output Impedance (Vbuf)
Figure 33.
Output Impedance (Vstby
Figure 34.
Ripple Rejection (VOUT
)
)
Figure 35.
Ripple Rejection (Vbuf
Figure 36.
Ripple Rejection (Vstby
)
)
Figure 37.
Figure 38.
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Typical Performance Characteristics (continued)
Device Dissipation vs
Ambient Temperature
Output Voltage
Figure 39.
Figure 40.
Output Capacitor ESR
(Standby Output, Pin 9)
Output Capacitor ESR
(Buffer Output, Pin 10)
Figure 41.
Figure 42.
Output Capacitor ESR
(Main Output, Pin 11)
Figure 43.
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APPLICATION HINTS
OUTPUT CAPACITORS
The LM2984 output capacitors are required for stability. Without them, the regulator outputs will oscillate,
sometimes by many volts. Though the 10 μF shown are the minimum recommended values, actual size and type
may vary depending upon the application load and temperature range. Capacitor effective series resistance
(ESR) also affects the IC stability. Since ESR varies from one brand to the next, some bench work may be
required to determine the minimum capacitor value to use in production. Worst case is usually determined at the
minimum ambient temperature and the maximum load expected.
Output capacitors can be increased in size to any desired value above the minimum. One possible purpose of
this would be to maintain the output voltages during brief conditions of negative input transients that might be
characteristic of a particular system.
Capacitors must also be rated at all ambient temperatures expected in the system. Many aluminum type
electrolytics will freeze at temperatures less than −30°C, reducing their effective capacitance to zero. To maintain
regulator stability down to −40°C, capacitors rated at that temperature (such as tantalums) must be used.
Each output must be terminated by a capacitor, even if it is not used.
STANDBY OUTPUT
The standby output is intended for use in systems requiring standby memory circuits. While the high current
regulator outputs are controlled with the ON/OFF pin described later, the standby output remains on under all
conditions as long as sufficient input voltage is supplied to the IC. Thus, memory and other circuits powered by
this output remain unaffected by positive line transients, thermal shutdown, etc.
The standby regulator circuit is designed so that the quiescent current to the IC is very low (<1.5 mA) when the
other regulator outputs are off.
The capacitor on the output of this regulator can be increased without bound. This will help maintain the output
voltage during negative input transients and will also help to reduce the noise on all three outputs. Because the
other two track the standby output: therefore any noise reduction here will also reduce the other two noise
voltages.
BUFFER OUTPUT
The buffer output is designed to drive peripheral sensor circuitry in a μP system. It will track the standby and
main regulator within a few millivolts in normal operation. Therefore, a peripheral sensor can be powered off this
supply and have the same operating voltage as the μP system. This is important if a ratiometric sensor system is
being used.
The buffer output can be short circuited while the other two outputs are in normal operation. This protects the μP
system from disruption of power when a sensor wire, etc. is temporarily shorted to ground, i.e. only the sensor
signal would be interrupted, while the μP and memory circuits would remain operational.
The buffer output is similar to the main output in that it is controlled by the ON/OFF switch in order to save power
in the standby mode. It is also fault protected against overvoltage and thermal overload. If the input voltage rises
above approximately 30V (e.g. load dump), this output will automatically shut down. This protects the internal
circuitry and enables the IC to survive higher voltage transients than would otherwise be expected. Thermal
shutdown is necessary since this output is one of the dominant sources of power dissipation in the IC.
MAIN OUTPUT
The main output is designed to power relatively large loads, i.e. approximately 500 mA. It is therefore also
protected against overvoltage and thermal overload.
This output will track the other two within a few millivolts in normal operation. It can therefore be used as a
reference voltage for any signal derived from circuitry powered off the standby or buffer outputs. This is important
in a ratiometric sensor system or any system requiring accurate matching of power supply voltages.
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ON/OFF SWITCH
The ON/OFF switch controls the main output and the buffer output. The threshold voltage is compatible with
most logic families and has about 20 mV of hysteresis to insure “clean” switching from the standby mode to the
active mode and vice versa. This pin can be tied to the input voltage through a 10 kΩ resistor if the regulator is to
be powered continuously.
POWER DOWN OVERRIDE
Another possible approach is to use a diode in series with the ON/OFF signal and another in series with the main
output in order to maintain power for some period of time after the ON/OFF signal has been removed (see
Figure 44). When the ON/OFF switch is initially pulled high through diode D1, the main output will turn on and
supply power through diode D2 to the ON/OFF switch effectively latching the main output. An open collector
transistor Q1 is connected to the ON/OFF pin along with the two diodes and forces the regulators off after a
period of time determined by the μP. In this way, the μP can override a power down command and store data, do
housekeeping, etc. before reverting back to the standby mode.
Figure 44. Power Down Override
RESET OUTPUT
This output is an open collector NPN transistor which is forced low whenever an error condition is present at the
main output or when a μP error is sensed (see μP MONITOR RESET section). If the main output voltage drops
by 350 mV or rises out of regulation by 600 mV typically, the RESET output is forced low and held low for a
period of time set by two external components, Rt and Ct. There is a slight amount of hysteresis in these two
threshold voltages so that the RESET output has a fast rise and fall time compatible with the requirements of
most μP RESET inputs.
DELAYED RESET
Resistor Rt and capacitor Ct set the period of time that the RESET output is held low after a main output error
condition has been sensed. The delay is given by the formula:
Tdly = 1.2 RtCt (seconds)
(1)
The delayed RESET will be initiated any time the main output is out of regulation, i.e. during power-up, short
circuit, overvoltage, low line, thermal shutdown or power-down. The μP is therefore RESET whenever the output
voltage is out of regulation. (It is important to note that a RESET is only initiated when the main output is in error.
The buffer and standby outputs are not directly monitored for error conditions.)
μP MONITOR RESET
There are two distinct and independent error monitoring systems in the LM2984. The one described above
monitors the main regulator output and initiates a delayed RESET whenever this output is in error. The other
error monitoring system is the μP watchdog. These two systems are OR'd together internally and both force the
RESET output low when either type of error occurs.
This watchdog circuitry continuously monitors a pin on the μP that generates a positive going pulse during
normal operation. The period of this pulse is typically on the order of milliseconds and the pulse width is typically
on the order of 10's of microseconds. If this pulse ever disappears, the watchdog circuitry will time out and a
RESET low will be sent to the μP. The time out period is determined by two external components, Rt and Cmon
,
according to the formula:
Twindow = 0.82 RtCmon (seconds)
(2)
16
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The width of the RESET pulse is set by Cmon and an internal resistor according to the following:
RESETpw = 2000 Cmon (seconds)
(3)
A square wave signal can also be monitored for errors by filtering the Cmon input such that only the positive
edges of the signal are detected. Figure 45 is a schematic diagram of a typical circuit used to differentiate the
input signal. Resistor Rtc and capacitor Ctc pass only the rising edge of the square wave and create a short
positive pulse suitable for the μP monitor input. If the incoming signal continues in a high state or in a low state
for too long a period of time, a RESET low will be generated.
Figure 45. Monitoring Square Wave μP Signals
The threshold voltage and input characteristics of this pin are compatible with nearly all logic families.
There is a limit on the width of a pulse that can be reliably detected by the watchdog circuit. This is due to the
output resistance of the transistor which discharges Cmon when a high state is detected at the input. The
minimum detectable pulse width can be determined by the following formula:
PWmin = 20 Cmon (seconds)
(4)
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Equivalent Schematic Diagram
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REVISION HISTORY
Changes from Revision B (March 2013) to Revision C
Page
•
Changed layout of National Data Sheet to TI format .......................................................................................................... 18
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PACKAGE OPTION ADDENDUM
www.ti.com
11-Apr-2013
PACKAGING INFORMATION
Orderable Device
Status Package Type Package Pins Package
Eco Plan Lead/Ball Finish
MSL Peak Temp
Op Temp (°C)
Top-Side Markings
Samples
Drawing
Qty
(1)
(2)
(3)
(4)
LM2984T
ACTIVE
TO-220
NDJ
11
20
TBD
Call TI
Call TI
-40 to 125
LM2984T
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4)
Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
MECHANICAL DATA
NDJ0011B
TA11B (Rev B)
www.ti.com
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