IC LDO REG W/SHTDWN ADJ 8-SOIC

LT1521CS8#TRPBF

Manufacturer Part NumberLT1521CS8#TRPBF
DescriptionIC LDO REG W/SHTDWN ADJ 8-SOIC
ManufacturerLinear Technology
LT1521CS8#TRPBF datasheet
 


Specifications of LT1521CS8#TRPBF

Regulator TopologyPositive AdjustableVoltage - Output3.8 ~ 20 V
Voltage - Input4.3 ~ 20 VVoltage - Dropout (typical)0.5V @ 300mA
Number Of Regulators1Current - Output300mA
Current - Limit (min)320mAOperating Temperature0°C ~ 125°C
Mounting TypeSurface MountPackage / Case8-SOIC (3.9mm Width)
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
1
Page 1
2
Page 2
3
Page 3
4
Page 4
5
Page 5
6
Page 6
7
Page 7
8
Page 8
9
Page 9
10
Page 10
11
12
13
14
15
16
Page 1/16

Download datasheet (201Kb)Embed
Next
FEATURES
Dropout Voltage: 0.5V
Output Current: 300mA
Quiescent Current: 12 A
No Protection Diodes Needed
Adjustable Output from 3.8V to 20V
Fixed Output Voltages: 3V, 3.3V, 5V
Controlled Quiescent Current in Dropout
Shutdown I
= 6 A
Q
Reverse Battery Protection
No Reverse Current
Thermal Limiting
U
APPLICATIO S
Low Current Regulator
Regulator for Battery-Powered Systems
Post Regulator for Switching Supplies
U
TYPICAL APPLICATIO
5V Battery-Powered Supply with Shutdown
8
IN
OUT
6V
1 F
LT1521-5
5
SHDN
SENSE
GND
3
V
(PIN 5) OUTPUT
SHDN
<0.25
OFF
>2.80
ON
NC
ON
Regulators with Micropower
Quiescent Current and Shutdown
DESCRIPTIO
®
The LT
1521/LT1521-3/LT1521-3.3/LT1521-5 are low
dropout regulators with micropower quiescent current
and shutdown. These devices are capable of supplying
300mA of output current with a dropout voltage of 0.5V.
Designed for use in battery-powered systems, the low
quiescent current, 12 A operating and 6 A in
shutdown, makes them an ideal choice. The quiescent
current is well controlled; it does not rise in dropout as it
does with many other low dropout PNP regulators.
Other features of the LT1521/LT1521-3/LT1521-3.3/
LT1521-5 include the ability to operate with very small
output capacitors. They are stable with only 1.5 F on the
output while most older devices require between 10 F and
100 F for stability. Small ceramic capacitors can be used,
enhancing manufacturability. Also, the input may be con-
nected to voltages lower than the output voltage, including
negative voltages, without reverse current flow from out-
put to input. This makes the LT1521 series ideal for backup
power situations where the output is held high and the
input is low or reversed. Under these conditions only 5 A
will flow from the output pin to ground.
, LTC and LT are registered trademarks of Linear Technology Corporation.
5V
1
300mA
+
1.5 F
2
LT1521 • TA01
LT1521/LT1521-3
LT1521-3.3/LT1521-5
300mA Low Dropout
U
Dropout Voltage
0.6
0.5
0.4
0.3
0.2
0.1
0
0
50
100
150
200
250
300
OUTPUT CURRENT (mA)
LT1521 • TA02
1521335fb
1

LT1521CS8#TRPBF Summary of contents

  • Page 1

    ... This makes the LT1521 series ideal for backup power situations where the output is held high and the input is low or reversed. Under these conditions only 5 A will flow from the output pin to ground. , LTC and LT are registered trademarks of Linear Technology Corporation 300mA + 1 ...

  • Page 2

    LT1521/LT1521-3 LT1521-3.3/LT1521 ABSOLUTE MAXIMUM Input Voltage ...................................................... 20V* Output Pin Reverse Current .................................. 10mA Adjust Pin Current ................................................ 10mA Shutdown Pin Input Voltage (Note 1) .......... 6.5V, – 0.6V Shutdown Pin Input Current (Note 1) ..................... 5mA ...

  • Page 3

    ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T PARAMETER CONDITIONS Regulated Output Voltage LT1521-3 (Note 4) LT1521-3.3 LT1521-5 LT1521 (Note 5) Line Regulation LT1521-3 LT1521-3.3 LT1521-5 LT1521 (Note 5) Load Regulation LT1521-3 LT1521-3.3 LT1521-5 LT1521 (Note 5) LT1521-3 LT1521-3.3 ...

  • Page 4

    LT1521/LT1521-3 LT1521-3.3/LT1521-5 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T PARAMETER CONDITIONS Input Reverse Leakage Current V Reverse Output Current (Note 11) LT1521-3 LT1521-3.3 LT1521-5 LT1521 (Note 5) Note 1: Absolute Maximum Ratings are those values beyond which the ...

  • Page 5

    W U TYPICAL PERFORMANCE CHARACTERISTICS LT1521-3 Output Voltage 3.08 3.06 3.04 3.02 3.00 2.98 2.96 2.94 2.92 –50 – 100 TEMPERATURE ( C) LT1521 • TPC04 LT1521 Adjust Pin Voltage 3. 1mA LOAD 3.81 ...

  • Page 6

    LT1521/LT1521-3 LT1521-3.3/LT1521 TYPICAL PERFORMANCE CHARACTERISTICS LT1521-3 Ground Pin Current *FOR OUT LOAD 300mA* LOAD LOAD 3 I ...

  • Page 7

    W U TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Pin Threshold (Off-to-On) 2.0 1 300mA LOAD 1.6 1.4 1 1mA LOAD 1.0 0.8 0.6 0.4 0.2 0 –50 – 100 125 TEMPERATURE ( C) LT1521 ...

  • Page 8

    LT1521/LT1521-3 LT1521-3.3/LT1521 TYPICAL PERFORMANCE CHARACTERISTICS Ripple Rejection 100 I = 150mA LOAD 50mV RIPPLE IN RMS 100 1k FREQUENCY (Hz) LT1521-5 Transient Response ...

  • Page 9

    PIN FUNCTIONS 5 IN OUT LT1521 + 4 V SHDN SENSE IN GND 3 Figure 1. Kelvin Sense Connection ADJ (Pin 2): For adjustable LT1521, the adjust pin is the input to the error amplifier. This pin ...

  • Page 10

    LT1521/LT1521-3 LT1521-3.3/LT1521 APPLICATIONS INFORMATION IN OUT V LT1521 IN SHDN ADJ GND 3.75V R2) OUT ADJ 3.75V ADJ I = 50nA ADJ OUTPUT RANGE ...

  • Page 11

    U U APPLICATIONS INFORMATION Table 3. SOT-223 Package (Thermal Resistance Junction-to-Tab 20 C/W) COPPER AREA TOPSIDE* BACKSIDE BOARD AREA 2500mm 2500mm 2500mm 1000mm 2500mm 2500mm 225mm 2500mm 2500mm ...

  • Page 12

    LT1521/LT1521-3 LT1521-3.3/LT1521 APPLICATIONS INFORMATION In circuits where a backup battery is required, several different input/output conditions can occur. The output voltage may be held up while the input is either pulled to ground, pulled to some intermediate voltage ...

  • Page 13

    U U APPLICATIONS INFORMATION Table 4. Fault Conditions INPUT PIN SHDN PIN < V (Nominal) Open (High) OUT < V (Nominal) Grounded OUT Open Open (High) Open Grounded 0.8V Open (High) 0.8V Grounded > 1.5V Open (High) – 20V < ...

  • Page 14

    LT1521/LT1521-3 LT1521-3.3/LT1521-5 PACKAGE DESCRIPTION 0.010 – 0.020 (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.016 – 0.050 (0.406 – 1.270) * DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION ...

  • Page 15

    ... MAX 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 its circuits as described herein will not infringe on existing patent rights Package 3-Lead Plastic SOT-223 (Reference LTC DWG # 05-08-1630) 0.248 – ...

  • Page 16

    ... Low Noise Micropower Low Dropout Regulator LT1763 500mA Low Noise Micropower Low Dropout Regulator LT1962 300mA Low Noise Micropower Low Dropout Regulator ThinSOT is a registered trademark of Linear Technology Corporation. Linear Technology Corporation 16 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 COMMENTS > ...