LM2941-ADJMDC [NSC]
5 V-20 V ADJUSTABLE POSITIVE LDO REGULATOR, UUC;
| 型号： | LM2941-ADJMDC |
| 厂家： | 
National Semiconductor |
| 描述： | 5 V-20 V ADJUSTABLE POSITIVE LDO REGULATOR, UUC |
| 文件： | 总15页 (文件大小：374K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
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November 7, 2007
LM2941/LM2941C
1A Low Dropout Adjustable Regulator
and the load. Familiar regulator features such as short circuit
and thermal overload protection are also provided.
General Description
The LM2941 positive voltage regulator features the ability to
source 1A of output current with a typical dropout voltage of
0.5V and a maximum of 1V over the entire temperature range.
Furthermore, a quiescent current reduction circuit has been
included which reduces the ground pin current when the dif-
ferential between the input voltage and the output voltage
exceeds approximately 3V. The quiescent current with 1A of
output current and an input-output differential of 5V is there-
fore only 30mA. Higher quiescent currents only exist when the
regulator is in the dropout mode (VIN − VOUT ≤ 3V).
Features
LLP space saving package
■
■
■
■
■
■
■
■
Output voltage adjustable from 5V to 20V
Dropout voltage typically 0.5V @ IO = 1A
Output current in excess of 1A
Trimmed reference voltage
Reverse battery protection
Internal short circuit current limit
Designed also for vehicular applications, the LM2941 and all
regulated circuitry are protected from reverse battery instal-
lations or two-battery jumps. During line transients, such as
load dump when the input voltage can momentarily exceed
the specified maximum operating voltage, the regulator will
automatically shut down to protect both the internal circuits
Mirror image insertion protection
P+ Product Enhancement tested
■
■
TTL, CMOS compatible ON/OFF switch
Connection Diagram and Ordering Information
TO-220 Plastic Package
TO-263 Surface-Mount Package
882309
882302
Top View
Order Number LM2941T or LM2941CT
See NS Package Number TO5A
882308
Order Number LM2941S, LM2941SX or
LM2941CS, LM2941CSX
See NS Package Number TS5B
16-Lead Ceramic Dual-in-Line Package
16-Lead Ceramic Surface Mount
Package
8-Lead LLP Surface Mount Package
882331
Top View
882332
882333
Order Number LM2941J/883
LM2941J-QMLV, 5962-9166701QEA
See NS Package Number J16A
Top View
Top View
Order Number LM2941WG/883
LM2941WG-QMLV, 5962-9166701QYA
See NS Package Number WG16A
Ordering Number LM2941LD,
LM2941LDX
See NS Package Number LDC08A
Note:
Pin 2 & 7 are fused to center DAP
© 2007 National Semiconductor Corporation
8823
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TO-263 (S) Package
ESD Rating (Note 2)
260°C
±2 kV
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Operating Ratings
Maximum Input Voltage
Temperature Range
LM2941T
26V
Input Voltage (Survival Voltage, ≤ 100ms)
LM2941T, LM2941S, LM2941LD
LM2941CT, LM2941CS
60V
45V
−40°C ≤ TJ ≤ 125°C
0°C ≤ TJ ≤ 125°C
−40°C ≤ TJ ≤ 125°C
0°C ≤ TJ ≤ 125°C
−55°C ≤ TJ ≤ 125°C
−55°C ≤ TJ ≤ 125°C
−40°C ≤ TJ ≤ 125°C
Internal Power Dissipation (Note 4)
Maximum Junction Temperature
Storage Temperature Range
Lead Temperature
Internally Limited
150°C
LM2941CT
LM2941S
−65°C ≤ TJ ≤ +150°C
LM2941CS
LM2941J
(Soldering, 10 seconds)
LM2941WG
LM2941LD
TO-220 (T) Package
260°C
Electrical Characteristics—LM2941T, LM2941S, LM2941J, LM2941WG,
LM2941LD
5V ≤ VO ≤ 20V, VIN = VO + 5V, CO = 22μF, unless otherwise specified. Specifications in standard typeface apply for TJ = 25°C,
while those in boldface type apply over the full Operating Temperature Range.
LM2941T
LM2941S
LM2941LD
Limit
(Note 6)
LM2941J
LM2941WG
Limit
Units
(Limits)
Parameter
Conditions
Typ
(Notes 3, 5)
Reference Voltage
1.237/1.211
1.237/1.211
V(min)
1.275
5mA ≤ IO ≤ 1A (Note 7)
1.313/1.339
10/10
1.313/1.339
10/10
V(max)
Line Regulation
Load Regulation
Output Impedance
4
7
7
mV/V(max)
VO + 2V ≤ VIN ≤ 26V, IO = 5mA
10/10
10/10
mV/V(max)
50mA ≤ IO ≤ 1A
100 mADC and 20 mArms
mΩ/V
fO = 120Hz
Quiescent Current
10
15/20
45/60
15/20
45/60
mA(max)
VO + 2V ≤ VIN < 26V, IO = 5mA
VIN = VO + 5V, IO = 1A
30
mA(max)
%
RMS Output Noise,
% of VOUT
10Hz–100kHz
IO = 5mA
0.003
Ripple Rejection
Long Term Stability
Dropout Voltage
fO = 120Hz, 1 Vrms, IL = 100mA
0.005
0.4
0.02/0.04
0.02/0.04
%/V(max)
%/1000 Hr
V(max)
IO = 1A
0.5
0.8/1.0
200/200
1.6/1.3
60/60
0.8/1.0
200/200
1.6
IO = 100mA
110
1.9
mV(max)
A(min)
Short Circuit Current
Maximum Line
Transient
VIN Max = 26V (Note 8)
VO Max 1V Above Nominal VO
RO = 100, T ≤ 100ms
75
60/60
V(min)
Maximum Operational
Input Voltage
VDC
31
26/26
26/26
Reverse Polarity DC Input
Voltage
RO = 100, VO ≥ −0.6V
T ≤ 100ms, RO = 100Ω
IO ≤ 1A
−30
−15/−15
−15/−15
V(min)
Reverse Polarity Transient
Input Voltage
−75
−50/−50
−50/−50
V(min)
V(max)
ON/OFF Threshold
Voltage ON
1.30
0.80/0.80
0.80/0.80
ON/OFF Threshold
Voltage OFF
1.30
50
2.00/2.00
100/300
2.00/2.00
100/300
V(min)
IO ≤ 1A
ON/OFF Threshold
Current
VON/OFF = 2.0V, IO ≤ 1A
μA(max)
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Electrical Characteristics—LM2941CT, LM2941CS
5V ≤ VO ≤ 20V, VIN = VO + 5V, CO = 22μF, unless otherwise specified. Specifications in standard typeface apply for TJ = 25°C,
while those in boldface type apply over the full Operating Temperature Range.
Parameter
Conditions
Typ
Limit
Units
(Limits)
V(min)
(Note 6)
Reference Voltage
1.237/1.211
1.275
5mA ≤ IO ≤ 1A (Note 7)
1.313/1.339
V(max)
Line Regulation
Load Regulation
Output Impedance
4
7
7
10
mV/V(max)
VO + 2V ≤ VIN ≤ 26V, IO = 5mA
10
mV/V(max)
50mA ≤ IO ≤ 1A
100 mADC and 20 mArms
mΩ/V
fO = 120Hz
Quiescent Current
10
15
mA(max)
VO + 2V ≤ VIN < 26V, IO = 5mA
VIN = VO + 5V, IO = 1A
30
45/60
mA(max)
%
RMS Output Noise,
% of VOUT
10Hz–100kHz
IO = 5mA
0.003
Ripple Rejection
Long Term Stability
Dropout Voltage
fO = 120Hz, 1 Vrms, IL = 100mA
0.005
0.4
0.02
%/V(max)
%/1000 Hr
V(max)
IO = 1A
0.5
0.8/1.0
200/200
1.6
IO = 100mA
110
1.9
mV(max)
A(min)
Short Circuit Current
Maximum Line
Transient
VIN Max = 26V (Note 8)
VO Max 1V Above Nominal VO
RO = 100Ω, T ≤ 100ms
55
45
V(min)
Maximum Operational Input
Voltage
VDC
31
26
Reverse Polarity DC Input Voltage
−30
−55
−15
−45
V(min)
V(min)
RO = 100Ω, VO ≥ −0.6V
T ≤ 100ms, RO = 100Ω
Reverse Polarity Transient Input
Voltage
ON/OFF Threshold Voltage ON
ON/OFF Threshold Voltage OFF
ON/OFF Threshold Current
1.30
1.30
50
0.80
2.00
100
V(max)
V(min)
IO ≤ 1A
IO ≤ 1A
VON/OFF = 2.0V, IO ≤ 1A
μA(max)
Thermal Performance
Thermal Resistance
Junction-to-Case
5-Lead TO-220
3
°C/W
°C/W
°C/W
°C/W
°C/W
5-Lead TO-263
5-Lead TO-220
5-Lead TO-263
8-Lead LLP (Note 4)
3
Thermal Resistance
Junction-to-Ambient
53
73
35
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions for which the device is
intended to be functional, but device parameter specifications may not be guaranteed under these conditions. For guaranteed specifications and test conditions,
see the Electrical Characteristics.
Note 2: The Human Body Model (HBM) is a 100 pF capacitor discharged through a 1.5kΩ resistor into each pin. Test method is per JESD22–A114.
Note 3: A military RETS specification available upon request. For more information about military-aerospace products, see the Mil-Aero web page at http://
www.national.com/appinfo/milaero/index.html.
Note 4: The maximum power dissipation is a function of TJ(max), θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD
=
(TJ(max) − TA)/θJA. If this dissipation is exceeded, the die temperature will rise above 150°C and the LM2941 will go into thermal shutdown. If the TO-263 package
is used, the thermal resistance can be reduced by increasing the P.C. board copper area thermally connected to the package: Using 0.5 square inches of copper
area, θJA is 50°C/W; with 1 square inch of copper area, θJA is 37°C/W; and with 1.6 or more square inches of copper area, θJA is 32°C/W. Thermal performance
for the LLP package was obtained using a JESD51-7 board with six vias, using no airflow and an ambient temperature of 22°C. The value θJA for the LLP package
is specifically dependent on PCB trace area, trace material, and the number of layers and thermal vias. For improved thermal resistance and power dissipation
for the LLP package, refer to Application Note AN-1187. It is recommended that 6 vias be placed under the center pad to improve thermal performance.
Note 5: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (boldface type). All limits are used to calculate Outgoing
Quality Level, and are 100% production tested.
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Note 6: All limits guaranteed at room temperature (standard typeface) and at temperature extremes (boldface type). All room temperature limits are 100%
production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods.
Note 7: The output voltage range is 5V to 20V and is determined by the two external resistors, R1 and R2. See Typical Application Circuit.
Note 8: Output current capability will decrease with increasing temperature, but will not go below 1A at the maximum specified temperatures.
Typical Performance Characteristics
Dropout Voltage
Dropout Voltage vs. Temperature
882311
882313
882315
882312
Output Voltage
Quiescent Current vs. Temperature
882314
Quiescent Current
Quiescent Current
882316
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Line Transient Response
Load Transient Response
882318
882317
Ripple Rejection
Output Impedance
882319
882320
Low Voltage Behavior
Low Voltage Behavior
882321
882322
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Output Capacitor ESR
Output at Voltage Extremes
882324
882323
Output at Voltage Extremes
Peak Output Current
882325
882326
Maximum Power Dissipation (TO-220)
Maximum Power Dissipation (TO-3)
882328
882327
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6
Maximum Power Dissipation (TO-263) (Note 4)
882329
Definition of Terms
Dropout Voltage: The input-voltage differential at which the
circuit ceases to regulate against further reduction in input
voltage. Measured when the output voltage has dropped
100mV from the nominal value obtained at (VOUT + 5V) input,
dropout voltage is dependent upon load current and junction
temperature.
Long Term Stability: Output voltage stability under accel-
erated life-test conditions after 1000 hours with maximum
rated voltage and junction temperature.
Output Noise Voltage: The rms AC voltage at the output,
with constant load and no input ripple, measured over a spec-
ified frequency range.
Input Voltage: The DC voltage applied to the input terminals
with respect to ground.
Quiescent Current: That part of the positive input current
that does not contribute to the positive load current. The reg-
ulator ground lead current.
Input-Output Differential: The voltage difference between
the unregulated input voltage and the regulated output volt-
age for which the regulator will operate.
Ripple Rejection: The ratio of the peak-to-peak input ripple
voltage to the peak-to-peak output ripple voltage.
Line Regulation: The change in output voltage for a change
in the input voltage. The measurement is made under condi-
tions of low dissipation or by using pulse techniques such that
the average chip temperature is not significantly affected.
Temperature Stability of VO: The percentage change in
output voltage for a thermal variation from room temperature
to either temperature extreme.
Load Regulation: The change in output voltage for a change
in load current at constant chip temperature.
Typical Applications
5V to 20V Adjustable Regulator
882303
Note: Using 1k for R1 will ensure that the input bias current error of the adjust pin will be negligible. Do not bypass R1 or R2. This will lead to instabilities.
7
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* Required if regulator is located far from power supply filter.
** COUT must be at least 22μF 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 and the ESR is critical; see curve.
1A Switch
882306
*** To assure shutdown, select Resistor R3 to guarantee at least 300μA of pull-up current when S1 is open. (Assume 2V at the ON/OFF pin.)
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8
Equivalent Schematic Diagram
882301
9
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Physical Dimensions inches (millimeters) unless otherwise noted
Order Number LM2941J/883
LM2941J-QMLV, 5962-9166701QEA
NS Package Number J16A
Order Number LM2941WG/883
LM2941WG-QMLV, 5962-9166701QYA
NS Package Number WG16A
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10
Order Number LM2941T or LM2941CT
NS Package Number T05A
TO-263 5-Lead Plastic Surface Mount Package
Order Number LM2941S, LM2941SX, LM2941CS or LM2941CSX
NS Package Number TS5B
11
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8-Lead LLP Surface Mount Package
Order Number LM2941LD, LM2941LDX
NS Package Number LDC08A
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12
Notes
13
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Notes
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