LND317 - Linear Dimensions Semiconductor

•
DATA SHEET
LND317
3-Terminal Adjustable Regulators
GENERAL DESCRIPTION
The LND317 is an adjustable 3-terminal positivevoltage regulator capable of supplying 1.5A over a
differential voltage range of 3V to 40V. It is
exceptionally easy to use and requires only two
external resistors to set the output voltage. Both
input and output regulation is better than standard
fixed regulators.
In addition to higher performance than fixed
regulators, the LND317 has full overload
protection available only in integrated circuits.
Included on the chip are current limit, thermal
overload protection, and safe-area protection. All
overload protection circuitry remains fully
functional even if the adjustment terminal is
disconnected. Normally, no capacitors are
needed unless the device is situated far from the
input filter capacitors in which case an input
bypass is needed. An optional output capacitor
can be added to improve transient response.
The primary applications of this device is that of a
programmable output regulator, but by connecting
a fixed resistor between adjustment terminal and
the output terminal, the device can be used as a
precision current regulator. Even though the
regulator is floating and sees only the input-to output differential voltage, use of these devices to
regulate output voltages that would cause the
maximum-rated differential voltage to be
exceeded if the output became shorted to ground
is not recommended.
FEATURES
•
Output Voltage Range Adjustable
from 1.2V to 37V
•
Output Current Capability of 1.5A Max
•
Input Regulation Typically 0.01% per
Input-Volt Change
•
Output Regulation Typically 0.1%
•
Peak Output Current Constant Over
Temperature Range of Regulator
•
Popular 3-Lead TO-220 Package
•
Ripple Rejection Typically 80 dB
•
Direct Replacement for National
LM317
INPUT
OUTPUT
ADJUST
TO-220
(Top View)
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
LM317
ABSOLUTE MAXIMUM RATING
(unless otherwise noted)
Input-to-Output differential voltage, VI -VO
Continuous total dissipation at 25ºC free-air
temperature
Continuous total dissipation at (or below) at 25ºC case
temperature
Operating free-air, case, or virtual junction
temperature range
Storage temperature range
Lead temperature 1.6mm (1/16 inch) from case for 10
seconds
LND317
Unit
40
V
2
W
15
W
0 to 125
ºC
-65 to 150
ºC
260
ºC
RECOMMENDED OPERATING CONDITIONS
LND317
MIN
MAX
10
0
1500
125
Output current, IO
Operating virtual junction temperature, TJ
UNIT
mA
ºC
TYPICAL APPLICATION DATA
VIN
VOUT
VIN
VOUT
LND317
R1
240
Adjust
C1
0.1µF
C2
R2
(see note A)
V OUT = V
REF
( )
R2
1+
R1
1 µF
(see note B)
+ IAdj R2
Note A: Use of an Input Bypass Capacitor is recommended if regulator is far from filter capacitors
Note B: Use of an output capacitor improves transient response, but is optional.
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
LND317
ELECTRICAL CHARACTERISTICS
Over recommended ranges of operating virtual junction temperature (unless otherwise noted) (see Note 1)
PARAMETER
TEST CONDITIONS
Input regulation( See Note 2)
VI-VO= 3V to 40V,
(See Note 3)
MIN
TJ=MIN to
MAX
0.01
IO =10mA to
1.5A
0.02
Output Regulation
Output Voltage Change with
temperature
Output voltage long-term
drift(see note 4)
Output noise voltage
Minimum output current to
maintain regulation
Peak output current
Adjustment terminal current
Change in adjustmentterminal current
Reference voltage(output to
ADJ)
0.04
0.07
65
VO=10 V, f=120 Hz
10-µF capacitor between ADJ and
ground
IO=10mA to 1.5 A,
VO ≤ 5V
TJ =25ºC,(See Note3)
VO > 5V
IO =10mA to 1.5A,
(see note 3)
UNIT
%/V
VO=10 V, f=120 Hz
Ripple rejection
LM317
TYP
MAX
66
dB
80
VO ≤ 5V
5
0.1
20
25
0.5
70
mV
%
mV
VO > 5V
0.3
1.5
%
TJ =MIN to MAX
1
After 1000h at TJ =MAX and
VI-VO=40V
f = 10Hz to 10kHz, TJ= 25ºC
0.3
VI-VO =2.5V to 40V,
IO=10mA to 1.5A
VI -VO = 3V to 40V, IO =10mA to 1.5A,
P≤15W
1
0.003
VI -VO = 40V
VI -VO ≤ 15V
VI -VO ≤ 40V, TJ =25ºC
%
3.5
1.5
0.15
1.2
%
%
10
mA
2.2
0.4
50
100
µA
0.2
5.0
µA
1.25
1.3
V
A
Unless otherwise noted, these specifications apply for the following test conditions: VI -VO=5V and IO= 0.5A. For conditions shown as
MIN or MAX, use the appropriate value specified under recommended operating conditions.
Notes:
1. All characteristics are measured with a 0.1-µF capacitor across the input and a 1-µF capacitor across the output.
2. Input regulation is expressed here as the percentage change in output voltage per 1-V change at the input.
3. Pulse testing techniques are used to maintain the junction temperature as close to the ambient temperature as possible.
Thermal effects must be taken into account separately.
4. Since long-term drift cannot be measured on the individual devices prior to shipment, this specification is not intended to be a
guarantee or warranty. It is an engineering estimate of the average drift to be expected from lot to lot.
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •
LND317
TYPICAL APPLICATIONS
D1
VOUT
VIN
VIN
VOUT
LND317
C1
I Adj
10 µ F
I OUT =
( )
VREF
R1
+ IAdj
= 1.25 V
R1
D1 protects against C1
D2 protects against C2
10 mA <=I OUT<= 1.5 A
Current Regulator
Regulator with Protection Diodes
VIN
I OUT
Adjust
+ C2
R2
R1
VOUT
VIN
LND317
D2
R1
240
Adjust
VIN
VOUT
VIN
24
LND317
Adjust
50 mA Constant Current Battery Charger
• Linear Dimensions, Inc. • 445 East Ohio Street, Chicago IL 60611 USA • tel 312.321.1810 • fax 312.321.1830 • www.lineardimensions.com •