数据搜索系统,热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

LM138 数据表(PDF) 6 Page - Linear Technology

部件名 LM138
功能描述  5A Positive Adjustable Voltage Regulator
Download  14 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  LINER [Linear Technology]
网页  http://www.linear.com
标志 LINER - Linear Technology

LM138 数据表(HTML) 6 Page - Linear Technology

Back Button LM138_15 Datasheet HTML 2Page - Linear Technology LM138_15 Datasheet HTML 3Page - Linear Technology LM138_15 Datasheet HTML 4Page - Linear Technology LM138_15 Datasheet HTML 5Page - Linear Technology LM138_15 Datasheet HTML 6Page - Linear Technology LM138_15 Datasheet HTML 7Page - Linear Technology LM138_15 Datasheet HTML 8Page - Linear Technology LM138_15 Datasheet HTML 9Page - Linear Technology LM138_15 Datasheet HTML 10Page - Linear Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 6 / 14 page
background image
LT138A/LT339A
LM138/LM338
6
138afd
For more information www.linear.com/LT138A
Typical perForMance characTerisTics
Line Transient Response
Load Transient Response
applicaTions inForMaTion
General
The LT138A develops a 1.25V reference voltage between
the output and the adjustable 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 5mA
or 10mA. Because IADJ is very small and constant when
comparedwiththecurrentthroughR1,itrepresentsasmall
error and can usually be ignored. It is easily seen from the
output voltage equation, that even if the resistors were of
exact value, the accuracy of the output is limited by the ac-
curacyofVREF.Earlieradjustableregulatorshadareference
tolerance of ± 4% which is dangerously close to the
±5% supply tolerance required in many logic and analog
systems. Further, even 1% resistors can drift 0.01%/°C,
adding additional error to the output voltage tolerance.
For example, using 2% resistors and ±4% tolerance for
VREF, calculations will show that the expected range of a
5V regulator design would be 4.66V ≤ VOUT ≤ 5.36V or
approximately ±7%. If the same example were used for a
15V regulator, the expected tolerance would be ±8%. With
these results most applications required some method of
trimming,usuallyatrimpot.Thissolutionisbothexpensive
and not conductive to volume production.
One of the enhancements of Linear Technology’s adjust-
able regulators over existing devices is the tightened initial
tolerance of VREF . This allows relatively inexpensive 1%
or 2% film resistors to be used for R1 and R2 to set the
output voltage within an acceptable tolerance.
With a guaranteed 1% reference, a 5V power supply
design, using ±2% resistors, would have a worst-case
manufacturing tolerance of ±4%. If 1% resistors are used,
the tolerance will drop to ±2.5%. A plot of the worst-case
output voltage tolerance as a function of resistor tolerance
is shown on the front page of this data sheet.
For convenience, a table of standard 1% resistor values
is shown in Table 1.
TIME (μs)
0
0
0.5
–1.5
–1.0
–0.5
20
30
1.5
138A/338A G13
1.0
10
40
0
0.5
1.0
CL = 1μF
CL = 10μF
COUT = 0
CADJ = 0
VOUT = 10V
IOUT = 50mA
TJ = 25°C
TIME (μs)
0
2
6
–3
–2
3
0
20
40
138A/338A G14
4
1
2
–1
0
10
30
VIN = 15V
VOUT = 10V
TCASE = 25°C
PRELOAD = 100mA
CL = 1μF
CADJ = 10μF
CL = 0
CADJ = 0
Figure 1. Basic Adjustable Regulator
LT338A
VIN
R1
138A/338A F01
VOUT
IADJ
50μA
ADJ
VREF
VOUT
VIN
R2
VOUT = VREF
R2
R1
1 +
+ IADJ • R2
( )
+


类似零件编号 - LM138_15

制造商部件名数据表功能描述
logo
Texas Instruments
LM138 TI1-LM138_16 Datasheet
2Mb / 23P
[Old version datasheet]   5-Amp Adjustable Regulators
More results

类似说明 - LM138_15

制造商部件名数据表功能描述
logo
Linear Technology
LT138A LINER-LT138A_15 Datasheet
225Kb / 14P
   5A Positive Adjustable Voltage Regulator
LT338A LINER-LT338A_15 Datasheet
225Kb / 14P
   5A Positive Adjustable Voltage Regulator
LT138A LINER-LT138A_01 Datasheet
148Kb / 12P
   5A Positive Adjustable Voltage Regulator
LT138A LINER-LT138A Datasheet
185Kb / 12P
   5A Positive Adjustable Voltage Regulator
LM338 LINER-LM338_15 Datasheet
225Kb / 14P
   5A Positive Adjustable Voltage Regulator
logo
Vishay Siliconix
GS1084 VISHAY-GS1084 Datasheet
57Kb / 6P
   5A Low Dropout Positive Adjustable Regulator
26-Mar-02
logo
Analog Intergrations Co...
AIC1084 AIC-AIC1084 Datasheet
104Kb / 6P
   5A Low Dropout Positive Adjustable Regulator
logo
International Rectifier
IRU1050 IRF-IRU1050 Datasheet
105Kb / 12P
   5A LOW DROPOUT POSITIVE ADJUSTABLE REGULATOR
logo
Linear Technology
RH1084MK LINER-RH1084MK_15 Datasheet
87Kb / 2P
   5A Low Dropout Positive Adjustable Regulator
logo
UNISEM
US1050 UNISEM-US1050 Datasheet
52Kb / 7P
   5A LOW DROPOUT POSITIVE ADJUSTABLE REGULATOR
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14


数据表 下载

Go To PDF Page


链接网址




隐私政策
ALLDATASHEETCN.COM
ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com