データシートサーチシステム
  Japanese  ▼
ALLDATASHEET.JP

X  

LM337 データシート(PDF) 7 Page - Linear Technology

部品番号 LM337
部品情報  Negative Adjustable Regulator
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
メーカー  LINER [Linear Technology]
ホームページ  http://www.linear.com
Logo LINER - Linear Technology

LM337 データシート(HTML) 7 Page - Linear Technology

Back Button LM337 Datasheet HTML 3Page - Linear Technology LM337 Datasheet HTML 4Page - Linear Technology LM337 Datasheet HTML 5Page - Linear Technology LM337 Datasheet HTML 6Page - Linear Technology LM337 Datasheet HTML 7Page - Linear Technology LM337 Datasheet HTML 8Page - Linear Technology LM337 Datasheet HTML 9Page - Linear Technology LM337 Datasheet HTML 10Page - Linear Technology LM337 Datasheet HTML 11Page - Linear Technology Next Button
Zoom Inzoom in Zoom Outzoom out
 7 / 12 page
background image
7
137afb
LT137A/LM137
LT337A/LM337
Output Voltage
The output voltage is determined by two external resis-
tors, R1 and R2 (see Figure 1). The exact formula for the
output voltage is:
VV
R
R
IR
OUT
REF
ADJ
=+
⎝⎜
⎠⎟
+
()
1
2
1
2
Where: VREF = Reference Voltage, IADJ = Adjustment Pin
Current. In most applications, the second term is small
enough to be ignored, typically about 0.5% of VOUT. In
more critical applications, the exact formula should be
used, with IADJ equal to 65μA. Solving for R2 yields:
R
VV
V
R
I
OUT
REF
REF
ADJ
2
1
=
+
Smaller values of R1 and R2 will reduce the influence
of IADJ on the output voltage, but the no-load current
drain on the regulator will be increased. Typical values
for R1 are between 100Ω and 300Ω, giving 12.5mA and
4.2mA no-load current respectively. There is an additional
consideration in selecting R1, the minimum load current
specification of the regulator. The operating current of the
LT137A flows from input to output. If this current is not
absorbed by the load, the output of the regulator will rise
above the regulated value. The current drawn by R1 and
R2 is normally high enough to absorb the current, but
care must be taken in no-load situations where R1 and
R2 have high values.
The maximum value for the operating current, which must
be absorbed, is 5mA for the LT137A. If input-output volt-
age differential is less than 10V, the operating current that
must be absorbed drops to 3mA.
APPLICATIONS INFORMATION
EXAMPLES:
1. A precision 10V regulator to supply up to 1A load
current.
a. Select R1 = 100Ω to minimize effect of IADJ
b. Calculate R2 =
VV
V
R
I
VV
V
μ
OUT
REF
REF
ADJ
–.
.
1
10
1 25
125
100
65
+
=
+
Ω
A
A
= 696 4
.
Ω
Use R2 = 698Ω
2. A 15V regulator to run off batteries and supply
50mA. VIN MAX = 25V
a. To minimize battery drain, select R1 as high as
possible
R
V
mA
1
125
3
417
==
.
ΩΩ
,use 402 ,1%
b. The high value for R1 will exaggerate the error due
to IADJ, so the exact formula to calculate R2 should
be used.
R
VV
V
R
I
VV
V
OUT
REF
REF
ADJ
2
1
15
1 25
125
402
=
+
=
+
–.
.
Ω
6
65
4331
μA
Use R2 = 4320Ω
Capacitors and Protection Diodes
An output capacitor, C3, is required to provide proper fre-
quency compensation of the regulator feedback loop. A 1μF
or larger solid tantalum capacitor is generally sufficient for
this purpose if the 1MHz impedance of the capacitor is 2Ω
or less. High Q capacitors, such as Mylar, are not recom-
mended because they tend to reduce the phase margin at
light load currents. Aluminum electrolytic capacitors may
also be used, but the minimum value should be 10μF to
ensure a low impedance at 1MHz. The output capacitor
should be located within a few inches of the regulator to
keep lead impedance to a minimum. The following caution
should be noted: if the output voltage is greater than 6V
and an output capacitor greater than 20μF has been used,
it is possible to damage the regulator if the input voltage
Figure 1
LT137A
ADJ
IADJ
VIN
–VIN
R2
VOUT
VREF
–VOUT
137A F01
+
R1
C3
1μF
+
C2
5μF
+
C1
10μF


同様の部品番号 - LM337

メーカー部品番号データシート部品情報
logo
ON Semiconductor
LM337 ONSEMI-LM337 Datasheet
172Kb / 8P
   THREE-TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATOR
1996 Rev 1
logo
Seme LAB
LM337 SEME-LAB-LM337 Datasheet
48Kb / 4P
   1.5 AMP NEGATIVE ADJUSTABLE VOLTAGE REGULATOR
logo
STMicroelectronics
LM337 STMICROELECTRONICS-LM337 Datasheet
245Kb / 14P
   THREE-TERMINAL ADJUSTABLE NEGATIVE VOLTAGE REGULATORS
March 1993
logo
ON Semiconductor
LM337 ONSEMI-LM337 Datasheet
160Kb / 10P
   1.5 A, Adjustable Output, Negative Voltage Regulator
April, 2012 ??Rev. 9
logo
Texas Instruments
LM337 TI-LM337 Datasheet
273Kb / 10P
[Old version datasheet]   3-TERMINAL ADJUSTABLE REGULATORS
More results

同様の説明 - LM337

メーカー部品番号データシート部品情報
logo
Linear Technology
LT137A LINER-LT137A Datasheet
795Kb / 8P
   Negative Adjustable Regulator
LM137 LINER-LM137_15 Datasheet
158Kb / 12P
   Negative Adjustable Regulator
RH137 LINER-RH137 Datasheet
163Kb / 4P
   Negative Adjustable Regulator
LT137A LINER-LT137A_1 Datasheet
167Kb / 12P
   Negative Adjustable Regulator
RH137 LINER-RH137_15 Datasheet
93Kb / 2P
   Negative Adjustable Regulator
LT137A LINER-LT137A_15 Datasheet
158Kb / 12P
   Negative Adjustable Regulator
LT337A LINER-LT337A_15 Datasheet
158Kb / 12P
   Negative Adjustable Regulator
LT1033 LINER-LT1033_02 Datasheet
193Kb / 12P
   3A Negative Adjustable Regulator
logo
Seme LAB
IP137SMD SEME-LAB-IP137SMD Datasheet
505Kb / 5P
   NEGATIVE ADJUSTABLE VOLTAGE REGULATOR
IP137SMD05 SEME-LAB-IP137SMD05_10 Datasheet
415Kb / 5P
   NEGATIVE ADJUSTABLE VOLTAGE REGULATOR
More results


Html Pages

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


データシート ダウンロード

Go To PDF Page


リンク URL




プライバシーポリシー
ALLDATASHEET.JP
ALLDATASHEETはお客様のビジネスに役立ちますか?  [ DONATE ] 

Alldatasheetは   |   広告   |   お問い合わせ   |   プライバシーポリシー   |   リンク交換   |   メーカーリスト
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