LINER LT1038MK 10amp positive adjustable voltage regulator Datasheet

LT1038
10A Positive
Adjustable Voltage
Regulator
OBSOLETE PRODUCT
DATA SHEET FOR REFERENCE ONLY
Consult www.linear.com for possible alternate source.
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FEATURES
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DESCRIPTIO
The LT®1038 is a three terminal regulator which is capable
of providing in excess of 10A output current over 1.2V to
32V range. The device is packaged in a standard T0-3
power package and is plug-in compatible with industry
standard adjustable regulators, such as the LM117 and
LM138. Also, the LT1038 is a functional replacement for
the LM396.
Guaranteed 0.8% Initial Tolerance
Guaranteed 0.4% Load Regulation
Guaranteed 10A Output Current
100% Thermal Limit Burn-In
24A Transient Output Current
Standard Adjustable Pinout
Operates to 35V
In addition to excellent load and line regulations, the
LT1038 is fully protected by current limiting, safe area
protection and thermal shutdown. New current limiting
circuitry allows transient load currents up to 24A to be
supplied for 500µs without causing the regulator to current limit and drop out of regulation during the transient.
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APPLICATIO S
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System Power Supplies
High Power Linear Regulator
Battery Chargers
Power Driver
Constant Current Regulator
On-chip trimming of initial reference voltage to ±0.8%
combined with 0.4% load regulation minimize errors in all
high current applications. Further, the LT1038 is manufactured with standard bipolar processing and has Linear
Technology’s high reliability.
, LTC and LT are registered trademarks of Linear Technology Corporation.
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TYPICAL APPLICATIONS
5V, 10A Regulator
Load Regulation
LT1038
VIN
VOUT
VIN ≥ 8V
+
ADJ
5V
AT 10A
121Ω
1%
1µF
+
10µF
365Ω
1%
1038 TA01
OUTPUT VOLTAGE DEVIATION (%)
0.2
0.1
VIN = 15V
VOUT = 10V
PRELOAD = 100mA
0
– 0.1
IOUT = 6A
IOUT = 10A
– 0.2
– 0.3
– 0.4
– 75 – 50 – 25
0 25 50 75 100 125 150
TEMPERATURE (°C)
1038 TA02
1
LT1038
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ABSOLUTE
AXI U RATI GS
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PACKAGE/ORDER I FOR ATIO
(Note 1)
BOTTOM VIEW
Power Dissipation ............................... Internally Limited
Input to Output Voltage Differential ......................... 35V
Operating Junction Temperature Range
LT1038M Control Circuitry ................ –55°C to 150°C
LT1038M Power Transistor ............... –55°C to 200°C
LT1038C Control Circuitry ..................... 0°C to 125°C
LT1038C Power Transistor .................... 0°C to 175°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
ORDER PART
NUMBER
VIN
2
LT1038MK
LT1038CK
1
CASE
IS OUTPUT
ADJ
K PACKAGE
2-LEAD TO-3 METAL CAN
TJMAX = 3°C, θJA = 35°C/W
OBSOLETE PACKAGE
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PRECO DITIO I G 100% Thermal Limit Burn-in
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 2)
SYMBOL
PARAMETER
VREF
Reference Voltage
CONDITIONS
IOUT = 20mA, Tj = 25°C
3V ≤ (VIN – VOUT) ≤ 35V
20mA ≤ IOUT ≤ 10A, P ≤ 75W
∆VOUT
∆VIN
Line Regulation
∆VOUT
∆IOUT
Load Regulation
ISC
1.26
1.23
1.25
1.275
V
1.25
1.285
1.22
1.25
1.285
V
MAX
UNITS
0.005
0.02
0.02
0.03
%/V
%/V
20mA ≤ IOUT ≤ 10A (Note 3)
3V ≤ (VIN – VOUT) ≤ 35V
3V ≤ (VIN – VOUT) ≤ 35V
●
0.1
0.3
0.4
0.8
0.1
0.3
0.6
1.0
%
%
0.002
0.005
0.002
0.01
%/W
●
●
60
60
75
●
50
20mA ≤ IOUT ≤ 10A
3V ≤ (VIN – VOUT) ≤ 35V
●
Minimum Load Current
(VIN – VOUT) = 35V
(VIN – VOUT) ≤ 20V
●
●
Current Limit
(VIN – VOUT) ≤ 10V
DC
Transient (0.5ms)
●
(VIN – VOUT) = 30V, Tj = 25°C
∆VOUT
∆Temp
Temperature Stability
∆VOUT
∆Time
Long Term Stability
TA = 125°C, 1000 Hours
en
RMS Output Noise
(% of VOUT)
10Hz ≤ f ≤ 10kHz
θJC
Thermal Resistance
Junction to Case
Power Transistor
Control Circuity
2
LT1038C
TYP
0.01
0.03
VOUT = 10V, f = 120Hz
CADJ = 0µF
CADJ = 10µF
Adjust Pin Current Change
1.25
1.22
MIN
0.005
0.02
Ripple Rejection
∆IADJ
1.24
MAX
●
20ms Pulse
Adjust Pin Current
LT1038M
TYP
3V ≤ (VIN – VOUT) ≤ 35V,
IOUT = 20mA (Note 3)
Thermal Regulation
IADJ
●
MIN
●
60
dB
dB
100
µA
100
50
0.2
3
0.2
3
µA
7
20
10
7
20
10
mA
mA
10
14
14
22
10
12
14
22
A
A
1
2
1
2
A
%
1
2
1
0.3
1
0.3
0.001
●
60
75
1
0.001
1
0.5
%
%
1
0.5
°C/W
°C/W
LT1038
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Unless otherwise specified, these specifications apply:
VIN – VOUT = 5V and IOUT = 5A. These specifications are applicable for
power dissipations up to 75W. At input-output voltage differentials greater
than 10V, achievable output current and power dissipation decrease due to
protection circuitry.
Note 3: See thermal regulation specifications for changes in output voltage
due to heating effects. Load and line regulation are measured at a constant
junction temperature by low duty cycle pulse testing.
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TYPICAL PERFOR A CE CHARACTERISTICS
Dropout Voltage
Adjustment Current
Temperature Stability
1.27
65
∆VOUT = 100mV
3
IOUT = 10A
IOUT = 6A
2
IOUT = 2A
REFERENCE VOLTAGE (V)
60
ADJUSTMENT CURRENT (µA)
55
50
45
40
1
– 75 – 50 – 25
30
– 75 – 50 – 25
0 25 50 75 100 125 150
TEMPERATURE (°C)
1.25
1.24
CADJ = 0µF
COUT = 0µF
0.1
CADJ = 10µF
COUT = 10µF
0.01
Ripple Rejection
10
100
8
80
CADJ = 10µF
QUIESCENT CURRENT (mA)
1
0.001
Tj = 150°C
6
Tj = 25°C
Tj = – 55°C
4
2
100
10k
1k
FREQUENCY (Hz)
100k
1M
1038 G04
CADJ = 0µF
60
40
VIN – VOUT = 5V
IOUT = 1A
f = 120Hz
Tj = 25°C
20
0
0.0001
10
25 50 75 100 125 150
TEMPERATURE (°C)
1038 G03
Minimum Operating Current
VIN = 15V
VOUT = 10V
IOUT = 1A
0
1038 G02
Output Impedance
10
1.23
–50 –25
0 25 50 75 100 125 150
TEMPERATURE (°C)
1038 TA02
OUTPUT IMPEDANCE (Ω)
1.26
35
RIPPLE REJECTION (dB)
INPUT-OUTPUT DIFFERENTIAL (V)
4
0
0
25 30 35
5
10 15 20
INPUT-OUTPUT DIFFERENTIAL (V)
40
1038 G05
0
5
20
15
10
25
OUTPUT VOLTAGE (V)
30
35
1038 G06
3
LT1038
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TYPICAL PERFOR A CE CHARACTERISTICS
Ripple Rejection
Ripple Rejection
40
70
60
50
20
40
10k
1k
FREQUENCY (Hz)
100k
1M
CADJ = 0µF
VIN = 15V
VOUT = 10V
f = 120Hz
TCASE = 25°C
PRELOAD = 0A
12
8
20
VIN – VOUT = 10V
16
0
0
100
1
TIME (ms)
10
100
TIME (ms)
LTXXX GXX
1038 G11
Load Transient Response
3
OUTPUT VOLTAGE
DEVIATION (V)
2
1
VIN = 15V
VOUT = 10V
TCASE = 25°C
PRELOAD = 200mA
0
CL = 0µF; CADJ = 0µF
–1
–2
CL = 1µF; CADJ = 10µF
LOAD CURRENT (A)
–3
6
4
2
0
0
10
20
TIME (µs)
30
CL = 1µF; CL = 10µF
0.5
VOUT = 10V
IOUT = 100mA
Tj = 25°C
0
– 0.5
COUT = 0A
CADJ = 0A
–1.5
VIN – VOUT = 30V
0.1
1.0
–1.0
VIN – VOUT = 20V
8
4
10
VIN – VOUT = 15V
12
4
1
Line Transient Response
OUTPUT VOLTAGE
DEVIATION (V)
PRELOAD = 10A
40
1195 G20
1.5
PRELOAD CURRENT = 0A
TCASE = 25°C
24
OUTPUT CURRENT (A)
OUTPUT CURRENT (A)
28
VIN = 10V
VOUT = 5V
TCASE = 25°C
20
20
10
30
INPUT-OUTPUT DIFFERENTIAL (V)
0
Current Limit
24
40
1038 G13
4
PRELOAD = 2A
8
1038 G08
Current Limit
28
0.1
PRELOAD = 10A
16
10
1038 G07
16
24
0
1
OUTPUT CURRENT (A)
0.1
INPUT VOLTAGE
CHANGE (V)
100
OUTPUT CURRENT (A)
CADJ = 0µF
10
PEAK CURRENT LIMIT
DC CURRENT LIMIT
TCASE = 25°C
PRELOAD = 0A
CADJ = 10µF
RIPPLE REJECTION (dB)
RIPPLE REJECTION (dB)
80
60
32
VIN = 15V
VOUT = 10V
IOUT = 1A
CADJ = 10µF
0
Current Limit
80
100
1.0
0.5
0
0
10
20
TIME (µs)
30
40
1038 G12
LT1038
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APPLICATIO S I FOR ATIO
General
The LT1038 develops a 1.25V reference voltage between
the output and the adjustment terminal (see Figure 1). By
placing a resistor, R1, between these two terminals, a
constant current is caused to flow through R1 and down
through R2 to set the overall output voltage. Normally this
current is the specified minimum load current of 10mA or
20mA. Because IADJ is very small and constant when
compared with the current through R1, it represents a
small error and can usually be ignored.
Bypass Capacitors
Input bypassing using a 1µF tantalum or 25µF electrolytic
is recommended when the input filter capacitors are more
than 5 inches from the device. Improved ripple rejection
(80dB) can be accomplished by adding a 10µF capacitor
from the ADJ pin to ground. Increasing the size of the
capacitor to 20µF will help ripple rejection at low output
voltage since the reactance of this capacitor should be
small compared to the voltage setting resistor, R2. For
improved AC transient response and to prevent the possibility of oscillation due to unknown reactive load, a 1µF
capacitor is also recommended at the output. Because of
their low impedance at high frequencies, the best type of
capacitor to use is solid tantalum.
Protection Diodes
The LT1038 does not require a protection diode from the
adjustment terminal to the output (see Figure 2). Improved internal circuitry eliminates the need for this diode
when the adjustment pin is bypassed with a capacitor to
improve ripple rejection.
If a very large output capacitor is used, such as a 100µF
shown in Figure 2, the regulator could be damaged or
destroyed if the input is accidentally shorted to ground or
crowbarred, due to the output capacitor discharging into
the output terminal of the regulator. To prevent this, a
diode, D1 as shown, is recommended to safely discharge
the capacitor.
Load Regulation
Because the LT1038 is a three-terminal device, it is not
possible to provide true remote load sensing. Load regulation will be limited by the resistance of the wire connecting the regulator to the load. The data sheet specification
for load regulation is measured at the bottom of the
package. Negative side sensing can be a true Kelvin
connection if the bottom of resistor R2 is returned to the
negative side of the load. Although it may not be immediately obvious, best load regulation is obtained when the
top of the resistor divider, R1, is connected directly to the
case, not to the load. This is illustrated in Figure 3. If R1
were connected to the load, the effective resistance between the regulator and the load would be:
 R2 + R1
Rp • 
 R = Parasitic Line Resistance
 R1  p
Connected as shown, Rp is not multiplied by the divider
ratio. Rp is about 0.004Ω per foot using 16 gauge wire.
This translates to 4mV/ft at 1A load current, so it is
important to keep the lead between the regulator and the
load as short as possible, and use large wire or PC board
traces.
D1
1N4002
VIN
VIN
LT1038
VOUT
ADJ
VOUT
VREF
VIN
LT1038
VIN
VOUT
R1
ADJ
IADJ
50µA
R2
) + IADJ R2
R1
1038 F01
+
R1
*
VOUT
COUT
100µF
VIN
LT1038
VOUT
CONNECT
R1 TO CASE
ADJ
RL
R1
R2
R2
VOUT = VREF (1 +
VIN
Rp
PARASITIC
LINE RESISTANCE
CADJ
10µF
+
R2
*NOT NEEDED
1038 F02
CONNECT R2
TO LOAD
1038 F03
Figure 1. Basic Adjustable Regulator
Figure 2
Figure 3. Connections for
Best Load Regulation
5
LT1038
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TYPICAL APPLICATIO S
Paralleling Regulators
VIN
VIN
LT1038
VOUT
2 FEET #18 WIRE*
ADJ
VOUT = 1.25 (1 +
0.015Ω
LT1038
VIN
IOUT = 0A TO 20A
R2
)
R1
VOUT
* THE #18 WIRE ACTS AS
BALLAST RESISTANCE
R1
INSURING CURRENT SHARING
120Ω BETWEEN BOTH DEVICES
ADJ
R2
1038 TA03
10A Variable Regulator*
T1
TRIAD
F-269U
L
1MHz
C30B
VIN
1N4003
20Ω
3
110V AC
20Ω
+
T2
1
LT1038
VOUT
ADJ
C1
50,000µF
750Ω*
1.5k
+
0V TO 35V
0A TO 10A
100µF
4
2
LT1004-1.2
C30B
LT1004-2.5
1N4003
1N4003
1µF
560Ω
16k*
15V
82k
LT1004-1.2
15k
8
2
3
10k
200k
–15V
+
4
LT1011
–
–15V
4
–
–15V
NC
100pF
2N3904
3
LT1011
1
+
10k
2
6
1
+
8
6
15V
3
LM301A
7
15k
GENERAL PURPOSE REGULATOR WITH SCR PREREGULATOR TO LOWER
POWER DISSIPATION. ABOUT 4V DIFFERENTIAL IS MAINTAINED ACROSS
THE LT1038 INDEPENDENT OF OUTPUT VOLTAGE AND LOAD CURRENT.
2.7k
0.1µF
15V
8
7
16k*
11k*
7
1
1N4148
*1% FILM RESISTOR
L-DALE TO-5 TYPE
T2-STANCOR 11Z-2003
20k
OUTPUT
ADJUST
15V
–
4
1µF –15V
2
11k*
1038 TA04
LT1038
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TYPICAL APPLICATIO S
Improving Ripple Rejection
VIN
VIN
LT1038
VOUT
5V
+
VIN
VIN
R1
121Ω
1%
ADJ
1µF
LT1038
VOUT
VOUT††
VIN
R1
121Ω
ADJ
LT1038
VOUT
VIN
5V
121Ω
1%
ADJ
+
1µF
+
R2
365Ω
1%
5V Regulator with Shutdown
1.2V to 25V Adjustable Regulator
+
C1*
1µF
C1*
10µF
+
R2
5k
C2†
1µF
1k
2N3904
TTL
365Ω
1%
1k
*C1 IMPROVES RIPPLE
REJECTION. XC SHOULD
BE SMALL COMPARED TO R2.
*NEEDED IF DEVICE IS FAR FROM FILTER CAPACITORS
†
OPTIONAL—IMPROVES TRANSIENT RESPONSE
††
VOUT = 1.25V (1 + R2/R1)
1038 TA06
1038 TA05
Remote Sensing
VIN
Temperature Compensated Lead Acid Battery Charger
10A
Rp
(MAX DROP 300mV)
LT1038
VOUT
VIN
ADJ
1038 TA07
VIN
VIN
5V
OUTPUT
LT1038
VOUT
ADJ
121Ω
1%
VIN
7
6
–
LM301A
+
25Ω
1
121Ω
2
50Ω
10k*
THERMALLY
COUPLED
+
25k
3 1k
RL
–
2N3906
12V
8
4
+
365Ω
5µF
2k*
CHARGE
100pF
50k*
2N3904
RETURN
25Ω
RETURN
*LOAD ON BATTERY ≈ 200µA
WHEN NOT CHARGING
1038 TA08
1038 TA09
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SCHE ATIC DIAGRA
VIN
Q24
310Ω
310Ω
190Ω
50Ω
5.6k
20k
300Ω
Q23
Q11
200Ω
Q4
Q6
Q27
Q9
Q26
Q2
Q15
30k
Q21
C3
5pF
3k
Q18
4k
Q1
130Ω
D1
6.3V
400Ω 160Ω
18k
16k
Q25
D2
6.3V
Q17
C1
30pF
Q12 Q13
Q3
160k
Q20
Q10
Q8
Q28
Q22
Q16
12.4k
12k
120Ω
1.6k
Q14
Q5
6.7k
Q19
C2
30pF
2.4k
160Ω
Q7
3Ω
180Ω
4.1k
6k
10k
5.1k
12k
0.005Ω
ADJ
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
VOUT
1038 SD
7
LT1038
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TYPICAL APPLICATIO S
Lamp Flasher
VIN
15V
12V
LT1038
VOUT
Automatic Light Control
Protected High Current Lamp Driver
ADJ
1µF
+
ADJ
12k
OFF
VOUT
VIN
15V
ADJ
1.2k
TTL OR
CMOS
10µF
+
1k
12V
10A
LT1038
LT1038
VIN
VOUT
10µF
2N3904
12k
10µF
10k
+
1039 TA12
1039 TA11
12k
1039 TA10
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PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
K Package
2-Lead TO-3 Metal Can
(60mil Diameter Leads)
(LTC DWG # 05-08-1312)
1.177 – 1.197
(29.90 – 30.40)
0.655 – 0.675
(16.64 – 17.15)
0.760 – 0.775
(19.30 – 19.69)
0.320 – 0.350
(8.13 – 8.89)
0.060 – 0.135
(1.524 – 3.429)
0.420 – 0.480
(10.67 – 12.19)
0.210 – 0.220
(5.33 – 5.59)
0.167 – 0.177
(4.24 – 4.49)
R
0.425 – 0.435
(10.80 – 11.05)
0.058 – 0.062
(1.47 – 1.57)
0.151 – 0.161
(3.86 – 4.09)
DIA, 2 PLACES
0.067 – 0.077
(1.70 – 1.96)
0.490 – 0.510
(12.45 – 12.95)
R
K2(TO-3) 1098
OBSOLETE PACKAGE
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1084
Low Dropout, 0.01% Load Regulation
7.5A Max Current Output
LT1581
Low Dropout, 430mV at 10A
Best Replacement
LT1584
Low Dropout, 0.05% Load Regulation
7A Max Current Output
LT1585
Low Dropout, 0.05% Load Regulation
5A Max Current Output
8
Linear Technology Corporation
1038fa LT/TP 0701 1.5K REV A • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
 LINEAR TECHNOLOGY CORPORATION 2000
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