LM350 3.0 A, Adjustable Output, Positive Voltage Regulator The LM350 is an adjustable three−terminal positive voltage regulator capable of supplying in excess of 3.0 A over an output voltage range of 1.2 V to 33 V. This voltage regulator is exceptionally easy to use and requires only two external resistors to set the output voltage. Further, it employs internal current limiting, thermal shutdown and safe area compensation, making it essentially blow−out proof. The LM350 serves a wide variety of applications including local, on card regulation. This device also makes an especially simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor between the adjustment and output, the LM350 can be used as a precision current regulator.
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THREE−TERMINAL ADJUSTABLE POSITIVE VOLTAGE REGULATOR
TO−220 T SUFFIX PLASTIC PACKAGE CASE 221AB
Features
• • • • • • • • • • •
Guaranteed 3.0 A Output Current Output Adjustable between 1.2 V and 33 V Load Regulation Typically 0.1% Line Regulation Typically 0.005%/V Internal Thermal Overload Protection Internal Short Circuit Current Limiting Constant with Temperature Output Transistor Safe Area Compensation Floating Operation for High Voltage Applications Standard 3−lead Transistor Package Eliminates Stocking Many Fixed Voltages Pb−Free Packages are Available* Vin
1
2
Pin 1. Adjust 2. Vout 3. Vin
3
Heatsink surface is connected to Pin 2.
MARKING DIAGRAM
vout
LM350
LM 350T AWLYWWG
R1 240
IAdj
Adjust
Cin* 0.1mF
+ C ** O 1mF
R2
A WL Y WW G
* = Cin is required if regulator is located an appreciable distance from power supply filter. ** = CO is not needed for stability, however, it does improve transient response. R Vout + 1.25 V 1 ) 2 ) IAdj R2 R1
ǒ
Ǔ
Since IAdj is controlled to less than 100 mA, the error associated with this term is negligible in most applications
= Assembly Location = Wafer Lot = Year = Work Week = Pb−Free Device
ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 3 of this data sheet.
Figure 1. Simplified Application *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. © Semiconductor Components Industries, LLC, 2006
August, 2006 − Rev. 4
1
Publication Order Number: LM350/D
LM350 MAXIMUM RATINGS Rating
Symbol
Value
Unit
VI−VO
35
Vdc
Power Dissipation
PD
Internally Limited
W
Operating Junction Temperature Range
TJ
−40 to +125
°C
Storage Temperature Range
Tstg
−65 to +150
°C
Tsolder
300
°C
Input−Output Voltage Differential
Soldering Lead Temperature (10 seconds)
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability.
ELECTRICAL CHARACTERISTICS (VI−VO = 5.0 V; IL = 1.5 A; TJ = Tlow to Thigh; Pmax [Note 1], unless otherwise noted.) Figure
Symbol
Min
Typ
Max
Unit
Line Regulation (Note 2) TA = 25°C, 3.0 V ≤ VI−VO ≤ 35 V
Characteristics
1
Regline
−
0.0005
0.03
%/V
Load Regulation (Note 2) TA = 25°C, 10 mA ≤ Il ≤ 3.0 A VO ≤ 5.0 V VO ≥ 5.0 V
2
Regload − −
5.0 0.1
25 0.5
mV % VO
Thermal Regulation, Pulse = 20 ms, (TA = +25°C)
Regtherm
−
0.002
−
% VO/W
3
IAdj
−
50
100
mA
Adjustment Pin Current Change 3.0 V ≤ VI−VO ≤ 35 V 10 mA ≤ IL ≤ 3.0 A, PD ≤ Pmax
1,2
DIAdj
−
0.2
5.0
mA
Reference Voltage 3.0 V ≤ VI−VO ≤ 35 V 10 mA ≤ IO ≤ 3.0 A, PD ≤ Pmax
3
Vref
1.20
1.25
1.30
V
Line Regulation (Note 2) 3.0 V ≤ VI−VO ≤ 35 V
1
Regline
−
0.02
0.07
%/V
Load Regulation (Note 2) 10 mA ≤ IL ≤ 3.0 A VO ≤ 5.0 V VO ≥ 5.0 V
2
Regload − −
20 0.3
70 1.5
mV % VO
Temperature Stability (Tlow ≤ TJ ≤ Thigh)
3
TS
−
1.0
−
% VO
Minimum Load Current to Maintain Regulation (VI−VO = 35 V)
3
ILmin
−
3.5
10
mA
Maximum Output Current VI−VO ≤ 10 V, PD ≤ Pmax VI−VO = 30 V, PD ≤ Pmax, TA = 25°C
3
Imax 3.0 0.25
4.5 1.0
− −
−
0.003
−
− 66
65 80
− −
−
0.3
1.0
− −
2.3 −
− 1.5
Adjustment Pin Current
RMS Noise, % of VO TA= 25°C, 10 Hz ≤ f ≤ 10 kHz
N
Ripple Rejection, VO = 10 V, f = 120 Hz (Note 3) Without CAdj CAdj = 10 mF
4
Long Term Stability, TJ = Thigh (Note 4) TA= 25°C for Endpoint Measurements
3
Thermal Resistance, Junction−to−Case Peak (Note 5) Average (Note 6)
A
RR
S
% VO dB
%/1.0 k Hrs. °C/W
RqJC
1. Tlow to Thigh = 0° to +125°C; Pmax = 25 W for LM350T; Tlow to Thigh = − 40° to +125°C; Pmax = 25 W for LM350BT 2. Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken into account separately. Pulse testing with low duty cycle is used. 3. CAdj, when used, is connected between the adjustment pin and ground. 4. Since Long−Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot. 5. Thermal Resistance evaluated measuring the hottest temperature on the die using an infrared scanner. This method of evaluation yields very accurate thermal resistance values which are conservative when compared to the other measurement techniques. 6. The average die temperature is used to derive the value of thermal resistance junction to case (average).
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LM350 ORDERING INFORMATION Operating Temperature Range
Device
Package
Shipping†
TO−220
50 Units / Rail
TO−220 (Pb−Free)
50 Units / Rail
LM350T TJ = 0° to + 125 °C
LM350TG
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D.
Vin 310
310
230
5.6K
120
6.3V
510
12.4K
13K
200
6.3V
30 pF
5.1K
110
5.8K
3.6K
30 pF
190
160
12K 5.0pF 6.8K
6.3V
135
125K
6.7K
170
2.4K
105
12.5K
4
0.45 Vout Adjust
Figure 2. Representative Schematic Diagram
VCC Line Regulation (%/V) = *
VOH − VOL VOL
VIH VIL
Vin
IL
Adjust Cin
*Pulse Testing Required: 1% Duty Cycleis suggested.
0.1mF
VOH VOL
Vout
LM350
R1
240 1%
RL + CO
IAdj
R2 1%
Figure 3. Line Regulation and DIAdj/Line Test Circuit
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x 100
1mF
LM350 Load Regulation (% VO) =
VO (min Load) − VO (max Load) VO (min Load)
X 100
Load Regulation (mV) = VO (min Load) −VO (max Load) Vin
Vin
Vout
LM350
VO (min Load) VO (max Load)
IL
Adjust
RL (max Load)
240 1%
R1
* +
Cin
0.1mF
CO
IAdj
RL (min Load)
1.0mF
R2 1% *Pulse Testing Required: 1% Duty Cycle is suggested.
Figure 4. Load Regulation and DIAdj/Load Test Circuit Vin
Vout
LM350
IL
Adjust
240 1%
R1
VI
IAdj Cin
Vref
RL +
0.1mF
CO
1.0mF
VO
ISET R2 1% To Calculate R2: Vout = ISET R2 + 1.250 V Assume ISET = 5.25 mA
Pulse Testing Required: 1% Duty Cycle is suggested.
Figure 5. Standard Test Circuit 24V Vin
14V f = 120 Hz
LM350
Vout
Adjust Cin
Vout = 10 V
IL
240 1%
R1
0.1mF
D1 * 1N4002 CO
R2
** CAdj
1.65K 1%
RL + 1.0mF
+ 10mF
*D1 Discharges CAdj if Output is Shorted to Ground. **CAdj provides an AC ground to the adjust pin.
Figure 6. Ripple Rejection Test Circuit
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VO
7
0.4 I out , OUTPUT CURRENT (A)
Δ Vout , OUTPUT VOLTAGE CHANGE (%)
LM350
0.2 0
IL = 0.5 A
−0.2 IL = 1.5 A
−0.4 −0.6
Vin = 15 V Vout = 10 V
−0.8 −1.0 −75
TJ = 55°C 5
TJ = 25°C
3
TJ = 150°C
1 −50
−25
0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C)
0
150
0
10 20 30 Vin−Vout, INPUT VOLTAGE DIFFERENTIAL (Vdc)
Figure 7. Load Regulation
Figure 8. Current Limit
V in −Vout , INPUT−OUTPUT VOLTAGE DIFFERENTIAL (Vdc)
IAdj, ADJUSTMENT PIN CURRENT (μA)
3.0 70 65 60 55 50 45 40 35 −75
−50
−25
0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C)
IL = 3.0 A IL = 2.0 A
2.0 IL = 500 mA 1.5 IL = 200 mA
IL = 20 mA 1.0 −75
150
DV0 = 100 mV
2.5
Figure 9. Adjustment Pin Current
−50
−25
0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C)
150
Figure 10. Dropout Voltage
1.260
5.0 IB , QUIESCENT CURRENT (mA)
Vref , REFERENCE VOLTAGE (V)
40
1.250
1.240
1.230
4.5
TJ = −55°C
4.0
TJ = 25°C
3.5 3.0
TJ = 150°C
2.5 2.0 1.5 1.0 0.5
1.220 −75
−50
−25
0 25 50 75 100 125 TJ, JUNCTION TEMPERATURE (°C)
0
150
0
Figure 11. Temperature Stability
10 20 30 40 Vin−Vout, INPUT−OUTPUT VOLTAGE DIFFERENTIAL (Vdc)
Figure 12. Minimum Operating Current
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LM350 100
140 RR, RIPPLE REJECTION (dB)
RR, RIPPLE REJECTION (dB)
CAdj = 10 mF 80 Without CAdj
60 40
Vin − Vout = 5 V IL = 500 mA f = 120 Hz TJ = 25°C
20 0
0
5
10
120 100
60 40 20
15 20 25 30 Vout, OUTPUT VOLTAGE (V)
0.1 1 Iout, OUTPUT CURRENT (A)
101 Z O , OUTPUT IMPEDANCE ( Ω)
IL = 500 mA Vin = 15 V Vout = 10 V TJ = 25°C
80 60 40
CAdj = 10 mF Without CAdj
20
100
1.0 k
10 k 100 k 1.0 M f, FREQUENCY (Hz)
100
10−1 Without CAdj 10−2 CAdj = 10 mF 10−3
10 M
Vin = 15 V Vout = 10 V IL = 500 mA TJ = 25°C
10
100
Δ Vout , OUTPUT VOLTAGE DEVIATION (V)
1.5 1.0 CL = 1.0 mF; CAdj = 10 mF
0.5 0 −0.5 Vout = 10 V IL = 50 mA TJ = 25°C
−1.0 −1.5
10
20
2 1
CL = 1.0 mF; CAdj = 10 mF
0 Vin = 15 V Vout = 10 V INL = 50 mA TJ = 25°C
−1 −2
CL = 0; Without CAdj
−3
IL
0.5
30
1.0 M
3
1.0
Vin 0
100 k
1.5
CL = 0; Without CAdj
1.0 0.5
1.0 k 10 k f, FREQUENCY (Hz)
Figure 16. Output Impedance
I L , LOAD CURRENT (A)
Δ Vin , INPUT VOLTAGE CHANGE (V)
Δ Vout , OUTPUT VOLTAGE DEVIATION (V)
Figure 15. Ripple Rejection versus Frequency
0
10
Figure 14. Ripple Rejection versus Output Current
100 RR, RIPPLE REJECTION (dB)
Without CAdj Vin − Vout = 5 V IL = 500 mA f = 120 Hz TJ = 25°C
0 0.01
35
Figure 13. Ripple Rejection versus Output Voltage
0 10
CAdj = 10 mF
80
40
0
t, TIME (ms)
20 t, TIME (ms)
Figure 17. Line Transient Response
Figure 18. Load Transient Response
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0
10
30
40
LM350 APPLICATIONS INFORMATION Basic Circuit Operation
External Capacitors
The LM350 is a three−terminal floating regulator. In operation, the LM350 develops and maintains a nominal 1.25 V reference (Vref) between its output and adjustment terminals. This reference voltage is converted to a programming current (IPROG) by R1 (see Figure 19), and this constant current flows through R2 to ground. The regulated output voltage is given by:
A 0.1 mF disc or 1 mF tantalum input bypass capacitor (Cin) is recommended to reduce the sensitivity to input line impedance. The adjustment terminal may be bypassed to ground to improve ripple rejection. This capacitor (CAdj) prevents ripple from being amplified as the output voltage is increased. A 10 mF capacitor should improve ripple rejection about 15 dB at 120 Hz in a 10 V application. Although the LM350 is stable with no output capacitance, like any feedback circuit, certain values of external capacitance can cause excessive ringing. An output capacitance (CO) in the form of a 1 mF tantalum or 25 mF aluminum electrolytic capacitor on the output swamps this effect and insures stability.
Vout = Vref (1 +
R2 ) + IAdj R2 R1
Since the current from the terminal (IAdj) represents an error term in the equation, the LM350 was designed to control IAdj to less than 100 mA and keep it constant. To do this, all quiescent operating current is returned to the output terminal. This imposes the requirement for a minimum load current. If the load current is less than this minimum, the output voltage will rise. Since the LM350 is a floating regulator, it is only the voltage differential across the circuit which is important to performance, and operation at high voltages with respect to ground is possible. Vin
LM350
Protection Diodes
When external capacitors are used with any IC regulator, it is sometimes necessary to add protection diodes to prevent the capacitors from discharging through low current points into the regulator. Figure 18 shows the LM350 with the recommended protection diodes for output voltages in excess of 25 V or high capacitance values (CO > 25 mF, CAdj > 10 mF). Diode D1 prevents CO from discharging thru the IC during an input short circuit. Diode D2 protects against capacitor CAdj discharging through the IC during an output short circuit. The combination of diodes D1 and D2 prevents CAdj from discharging through the IC during an input short circuit.
Vout + R1 Vref
Adjust
IPROG Vout
IAdj
R2
D1
Vref = 1.25 V Typical
1N4002 Vin
Figure 19. Basic Circuit Configuration
LM350
Vout +
Load Regulation
Cin
The LM350 is capable of providing extremely good load regulation, but a few precautions are needed to obtain maximum performance. For best performance, the programming resistor (R1) should be connected as close to the regulator as possible to minimize line drops which effectively appear in series with the reference, thereby degrading regulation. The ground end of R2 can be returned near the load ground to provide remote ground sensing and improve load regulation.
R1
D2
Adjust
1N4002 R2
CAdj
Figure 20. Voltage Regulator with Protection Diodes
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CO
LM350 D6 1N4002 Vin 32V
Vout1 RSC
LM350 (1)
Vin1
Vin2
IO
Vout 2
LM350 (2)
VO 240
0.1mF D1 1N4001
Adjust 1 1K
Current Limit Adjust
Adjust 2
1N4001 D2
5.0K
1.0mF Tantalum
+ 10mF
Voltage Adjust 1N4001
Q1 2N3822
+
D5 IN4001
D3 D4
−10V
Q2 2N5640
Diodes D1 and D2 and transistor Q2 are added to allow adjustment of output voltage to 0 V.
Output Range: 0 ≤ VO ≤ 25 V 0 ≤ IO ≤ 1.5 A
1N4001
−10V
D6 protects both LM350’s during an input short circuit.
Figure 21. “Laboratory” Power Supply with Adjustable Current Limit and Output Voltage
+25V
Vout
LM350
Vout
R1
Iout
620
Vin Adjust
D1 D1 1N4001
R2 100
* To provide current limiting of IO to the system ground, the source of the FET must be tied to a negative voltage below −1.25 V. Vref R2 ≤ IDSS Vref R1 = IOmax + IDSS
1N4002 Vin
D2 1N4001
Vout
LM350
+ Adjust
2N5640
MPS2222 720 1.0k
VSS*
D1 protects the device during an input short circuit.
Figure 22. Adjustable Current Limiter
Figure 23. 5.0 V Electronic Shutdown Regulator
Vin LM350
1N4001 Adjust
Adjust
50k MPS2907
Vout
LM350
Vout 240
R2
TTL Control
Minimum Vout = 1.25 V
VO < V(BR)DSS + 1.25 V + VSS ILmin − IDSS < IO < 3.0 A As shown O < IO < 1.0 A
Vin
1.0mF
120
IAdj Iout +
+ 10mF
R1
ǒVRref1 Ǔ ) IAdj
^ 1.25 V R1 10 mA ≤ Iout ≤ 3.0 A
Figure 24. Slow Turn−On Regulator
Figure 25. Current Regulator
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Iout
LM350 PACKAGE DIMENSIONS
TO−220, SINGLE GAUGE T SUFFIX CASE 221AB−01 ISSUE O
−T− B
SEATING PLANE
C
F T
S
4
DIM A B C D F G H J K L N Q R S T U V Z
A
Q 1 2 3
U
H K Z L
R
V
NOTES: 1. DIMENSIONING AND TOLERANCING PER ANSI Y14.5M, 1982. 2. CONTROLLING DIMENSION: INCH. 3. DIMENSION Z DEFINES A ZONE WHERE ALL BODY AND LEAD IRREGULARITIES ARE ALLOWED.
J
G D N
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INCHES MIN MAX 0.570 0.620 0.380 0.405 0.160 0.190 0.025 0.035 0.142 0.147 0.095 0.105 0.110 0.155 0.018 0.025 0.500 0.562 0.045 0.060 0.190 0.210 0.100 0.120 0.080 0.110 0.020 0.055 0.235 0.255 0.000 0.050 0.045 −−− −−− 0.080
MILLIMETERS MIN MAX 14.48 15.75 9.66 10.28 4.07 4.82 0.64 0.88 3.61 3.73 2.42 2.66 2.80 3.93 0.46 0.64 12.70 14.27 1.15 1.52 4.83 5.33 2.54 3.04 2.04 2.79 0.508 1.39 5.97 6.47 0.00 1.27 1.15 −−− −−− 2.04
LM350
ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
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[email protected]
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LM350/D
