IC LDO REG 3.3V/ADJ 3A DDPAK-5

LT1528CQ#TRPBF

Manufacturer Part NumberLT1528CQ#TRPBF
DescriptionIC LDO REG 3.3V/ADJ 3A DDPAK-5
ManufacturerLinear Technology
LT1528CQ#TRPBF datasheet
 

Specifications of LT1528CQ#TRPBF

Regulator TopologyPositive Fixed and AdjustableVoltage - Output3.3V, 3.3 ~ 14.15 V
Voltage - Input3.9 ~ 15 VVoltage - Dropout (typical)0.57V @ 3A
Number Of Regulators1Current - Output3A
Current - Limit (min)3.2AOperating Temperature0°C ~ 125°C
Mounting TypeSurface MountPackage / CaseTO-263-5, D²Pak (5 leads + Tab), TO-263BA
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
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FEATURES
n
Dropout Voltage: 0.6V at I
= 3A
OUT
n
Fast Transient Response
n
Output Current: 3A
n
Quiescent Current: 400μA
n
No Protection Diodes Needed
n
Fixed Output Voltage: 3.3V
n
Controlled Quiescent Current in Dropout
n
Shutdown I
= 125μA
Q
n
Stable with 3.3μF Output Capacitor
n
Reverse Battery Protection
n
No Reverse Output Current
n
Thermal Limiting
APPLICATIONS
n
Microprocessor Applications
n
Post Regulator for Switching Supplies
n
5V to 3.3V Logic Regulator
TYPICAL APPLICATION
Microprocessor Supply with Shutdown
5
1
IN
OUT
V
=5V
LT1528
IN
J1
4
2
SHDN
SENSE
GND
330Ω
3
V
(PIN 4)
OUTPUT
SHORTING
V
SHDN
<0.25
OFF
J1
3.30
>2.80
ON
J2
3.45
NC
ON
J3
4.00
3A Low Dropout Regulator
for Microprocessor Applications
DESCRIPTION
The LT
®
1528 is a 3A low dropout regulator optimized to
handle the large load current transients associated with
the current generation of microprocessors. This device has
the fastest transient response of currently available PNP
regulators and is very tolerant of variations in capacitor
ESR. Dropout voltage is 75mV at 10mA, rising to 300mV
at 1A and 600mV at 3A. The device has a quiescent cur-
rent of 400μA. Quiescent current is well controlled; it does
not increase signifi cantly as the device enters dropout.
The regulator can operate with output capacitors as small
as 3.3μF, although larger capacitors will be needed to
achieve the performance required in most microprocessor
applications. The LT1528 is available with a fi xed output
voltage of 3.3V. An external SENSE pin allows adjustment
to output voltages greater than 3.3V, using a simple resis-
tive divider. This allows the device to be adjusted over a
wide range of output voltages, including the 3.3V to 4.2V
range required by a variety of processors from Intel, IBM,
AMD, and Cyrix.
The LT1528 has both reverse input and reverse output
protection and includes a shutdown feature. Quiescent
current drops to 125μA in shutdown. The LT1528 is avail-
able in 5-lead TO-220 and 5-lead DD-PAK packages.
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
V
OUT
+
4 × 47μF*
15Ω
68Ω
SOLID TANTALUM
J2
J3
*CHOOSE CAPACITORS
OUT
TO MEET PROCESSOR
REQUIREMENTS
1528 TA01
LT1528
Dropout Voltage
0.6
0.5
0.4
0.3
0.2
0.1
0
0
1.0
1.5
2.0
2.5
3.0
0.5
OUTPUT CURRENT (mA)
1528 TA02
1528fb
1

LT1528CQ#TRPBF Summary of contents

  • Page 1

    ... Quiescent current drops to 125μA in shutdown. The LT1528 is avail- able in 5-lead TO-220 and 5-lead DD-PAK packages. L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. V OUT + 4 × ...

  • Page 2

    ... PLASTIC 125°C, θ = 30°C/ W JMAX JA ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL LT1528CQ#PBF LT1528CQ#TRPBF LT1528CT#PBF LT1528CT#TRPBF LEAD BASED FINISH TAPE AND REEL LT1528CQ LT1528CQ#TR LT1528CT LT1528CT#TR Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. ...

  • Page 3

    ELECTRICAL CHARACTERISTICS temperature range, otherwise specifi cations are at T PARAMETER Dropout Voltage (Note 5) GND Pin Current (Note 6) SENSE Pin Current (Notes 4, 8) SHDN Threshold SHDN Pin Current (Note 9) Quiescent Current in Shutdown (Note 10) Ripple ...

  • Page 4

    LT1528 TYPICAL PERFORMANCE CHARACTERISTICS Guaranteed Dropout Voltage 1.0 = TEST POINTS 0.9 0.8 0.7 T ≤ 125°C J 0.6 0.5 T ≤ 25°C J 0.4 0.3 0.2 0 0.5 1.5 2.0 2.5 1.0 OUTPUT CURRENT (A) 1528 TPC01 ...

  • Page 5

    TYPICAL PERFORMANCE CHARACTERISTICS SHDN Pin Threshold (Off-to-On) 2.0 1 1.6 LOAD 1.4 1 1mA LOAD 1.0 0.8 0.6 0.4 0.2 0 – 125 –25 100 TEMPERATURE (°C) 1528 TPC10 SENSE Pin ...

  • Page 6

    LT1528 TYPICAL PERFORMANCE CHARACTERISTICS Ripple Rejection × 47μF OUT SOLID TANTALUM 47μF OUT 30 SOLID TANTALUM 1.5A OUT 50mV RIPPLE IN RMS ...

  • Page 7

    PIN FUNCTIONS SHDN (Pin 4): This pin is used to put the device into shutdown. In shutdown the output of the device is turned off. This pin is active low. The device will be shut down if the SHDN pin ...

  • Page 8

    LT1528 APPLICATIONS INFORMATION The LT1528 is specifi ed with the SENSE pin tied to the OUTPUT pin. This sets the output voltage to 3.3V. Specifi cations for output voltage greater than 3.3V will be proportional to the ratio of the ...

  • Page 9

    APPLICATIONS INFORMATION The maximum junction temperature will be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or 50°C + 31.4°C = 81.4°C JMAX Output Capacitance and Transient Performance The LT1528 is designed ...

  • Page 10

    LT1528 APPLICATIONS INFORMATION The reverse output current will follow the curve in Figure 3 when the input is pulled to ground. This current fl ows through the OUTPUT pin to ground. The state of the SHDN pin will have no ...

  • Page 11

    ... 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. Q Package ...

  • Page 12

    ... TYP .095 – .115 (2.413 – 2.921) .155 – .195* (3.937 – 4.953) .013 – .023 (0.330 – 0.584) * MEASURED AT THE SEATING PLANE T5 (TO-220) 0801 LT 0508 REV B • PRINTED IN USA © LINEAR TECHNOLOGY CORPORATION 1995 1528fb ...