LT1185CQ#TR Linear Technology, LT1185CQ#TR Datasheet

IC REG LDO ADJUSTABLE 3A DDPAK-5

LT1185CQ#TR

Manufacturer Part Number
LT1185CQ#TR
Description
IC REG LDO ADJUSTABLE 3A DDPAK-5
Manufacturer
Linear Technology
Datasheet

Specifications of LT1185CQ#TR

Regulator Topology
Negative Adjustable
Voltage - Output
-2.5 ~ -25 V
Voltage - Input
-4.2 ~ -35 V
Voltage - Dropout (typical)
0.67V @ 3A
Number Of Regulators
1
Current - Output
3A
Current - Limit (min)
Adjustable
Operating Temperature
0°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
TO-263-5, D²Pak (5 leads + Tab), TO-263BA
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LT1185CQ#TRLT1185CQ
Manufacturer:
LT
Quantity:
5 510
Company:
Part Number:
LT1185CQ#TRLT1185CQ
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Company:
Part Number:
LT1185CQ#TRLT1185CQ#PBF
Manufacturer:
ADI/亚德诺
Quantity:
20 000
Company:
Part Number:
LT1185CQ#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
FEATURES
DESCRIPTIO
6V TO 16V
TYPICAL APPLICATIO
The LT
current limit and remote sense capability. It can be used as
a positive output regulator with floating input or as a
standard negative regulator with grounded input. The
output voltage range is 2.5V to 25V, with ±1% accuracy on
the internal reference voltage.
+
V
Low Resistance Pass Transistor: 0.25
Dropout Voltage: 0.75V at 3A
±
Accurate Programmable Current Limit
Shutdown Capability
Internal Reference Available
Full Remote Sense
Low Quiescent Current: 2.5mA
Good High Frequency Ripple Rejection
Available in 5-Lead TO-220 and DD Packages
IN
1% Reference Voltage
*CURRENT LIMIT = 15k/R
®
1185 is a 3A low dropout regulator with adjustable
+
5V, 3A Regulator with 3.5A Current Limit
2µF
TANT
V
IN
REF
U
R
4.3k
LIM
LIM
LT1185
*
= 3.5A
GND
V
OUT
FB
U
2.37k
2.67k
+
2µF
TANT
LT1185 • TA01
5V AT 3A
V
OUT
+
The LT1185 uses a saturation-limited NPN transistor as
the pass element. This device gives the linear dropout
characteristics of a FET pass element with significantly
less die area. High efficiency is maintained by using special
anti-saturation circuitry that adjusts base drive to track
load current. The “on resistance” is typically 0.25Ω.
Accurate current limit is programmed with a single 1/8W
external resistor, with a range of zero to three amperes. A
second, fixed internal limit circuit prevents destructive
currents if the programming current is accidentally over-
ranged. Shutdown of the regulator output is guaranteed
when the program current is less than 1µA, allowing
external logic control of output voltage.
The LT1185 has all the protection features of previous
LTC regulators, including power limiting and thermal
shutdown.
All other trademarks are the property of their respective owners.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Low Dropout Regulator
1.0
1.6
1.4
1.2
0.8
0.6
0.4
0.2
0
0
1
T
Dropout Voltage
J
LOAD CURRENT (A)
= 125°C
T
T
J
J
2
= 25°C
= –55°C
3
LT1185 • TA02
4
LT1185
1185ff
1

Related parts for LT1185CQ#TR

LT1185CQ#TR Summary of contents

Page 1

... The LT1185 has all the protection features of previous LTC regulators, including power limiting and thermal shutdown. , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. 1.6 + 1.4 2 ...

Page 2

LT1185 ABSOLUTE AXI U RATI GS Input Voltage .......................................................... 35V Input-Output Differential ......................................... 30V FB Voltage ................................................................ 7V REF Voltage .............................................................. 7V Output Voltage ........................................................ 30V Output Reverse Voltage ............................................ 2V Operating Ambient Temperature Range LT1185C ............................................... ...

Page 3

ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the operating temperature range, otherwise specifications are at T Adjustable version 7.4V 5V OUT PARAMETER Load Regulation (Note 7) Line Regulation (Note 7) Minimum Input ...

Page 4

LT1185 W U TYPICAL PERFOR A CE CHARACTERISTICS Internal Current Limit 5 4 GUARANTEED LIMIT 3 TYPICAL 2 GUARANTEED 1 LIMIT TEST POINTS INPUT-OUTPUT DIFFERENTIAL (V) LT1185 • TPC01 Ground Pin Current 160 ...

Page 5

U U APPLICATIO S I FOR ATIO Block Diagram A simplified block diagram of the LT1185 is shown in Figure 1. A 2.37V bandgap reference is used to bias the input of the error amplifier A1, and the reference amplifier ...

Page 6

LT1185 U U APPLICATIO S I FOR ATIO Amplifier A2 is used to generate an internal current through Q4 when an external resistor is connected from the REF pin to ground. This current is equal to 2.37V divided by R ...

Page 7

U U APPLICATIO S I FOR ATIO Large output capacitors (electrolytic or solid tantalum) will not cause the LT1185 to oscillate, but they will cause a damped “ringing” at light load currents where the ESR of the capacitor is several ...

Page 8

LT1185 U U APPLICATIO S I FOR ATIO factor is that local ambient temperature may be somewhat higher because of the point source of heat. The conse- quences of excess junction temperature include poor reliability, especially for plastic packages, and ...

Page 9

U U APPLICATIO S I FOR ATIO for remote sense applications, they may need to be con- sidered. Ground lead resistance of 0.4Ω would cause an output voltage error (3A/40)(0.4Ω) = 30mV ...

Page 10

LT1185 U U APPLICATIO S I FOR ATIO Thermal Regulation IC regulators have a regulation term not found in discrete designs because the power transistor is thermally coupled to the reference. This creates a shift in the output voltage which ...

Page 11

U TYPICAL APPLICATIO 15k + 2µF 2N3906 V IN TANT GND REF – V LT1185 IN V OUT LT1185 • TA03a Auxiliary + 12V Low Dropout Regulator for Switching Supply PRIMARY *DIODE CONNECTION INDICATES A FLYBACK SWITCHING ...

Page 12

LT1185 U TYPICAL APPLICATIO 360k 2.2µF TANT V IN REF R4** 1k R5* 0.01Ω – R6** 1k OPTIONAL HYSTERESIS 3 + LT1006 2 – Time Delayed Start-Up + R3** † ...

Page 13

W W SCHE ATIC DIAGRA LT1185 1185ff 13 ...

Page 14

LT1185 PACKAGE DESCRIPTIO .320 – .350 (19.30 – 19.69) (8.13 – 8.89) .420 – .480 (10.67 – 12.19) .390 – .415 (9.906 – 10.541) .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .330 – .370 (8.382 ...

Page 15

... DIMENSIONS IN INCH/(MILLIMETER) 2. DRAWING NOT TO SCALE 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 represen- tation that the interconnection of circuits as described herein will not infringe on existing patent rights Package ...

Page 16

... Supply Current, Adjustable Current Limit For High Performance Microprocessors V : –0.9V to –20V 3µA, ThinSOT Package SD www.linear.com ● 1N4001 ADD FOR INDUCTIVE LOADS + C1 4.7µF V OUT TANT C3 0.05µF – = 5V, OUT = –1.21V 0.34V 30µA, OUT(MIN LT/LWI 0906 REV F • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1994 1185ff ...

Related keywords