Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsPMICsPMIC - LDO voltage regulator Positivbe, adjustable DFN 12 (4x4)

LT3083

3083fa

TYPICAL APPLICATION

DESCRIPTION

Adjustable 3A

Single Resistor Low

Dropout Regulator

The LT

3083 is a 3A low dropout linear regulator that can

be paralleled to increase output current or spread heat on

surface mounted boards. Architected as a precision current

source and voltage follower, this new regulator ﬁnds use

in many applications requiring high current, adjustability

to zero, and no heat sink. The device also brings out the

collector of the pass transistor to allow low dropout opera-

tion—down to 310mV—when used with multiple supplies.

A key feature of the LT3083 is the capability to supply a

wide output voltage range. By using a reference current

through a single resistor, the output voltage is programmed

to any level between zero and 23V (DD-PAK and TO-220

packages). The LT3083 is stable with 10µF of capacitance

on the output, and the IC is stable with small ceramic ca-

pacitors that do not require additional ESR as is common

with other regulators.

Internal protection circuitry includes current limiting and

thermal limiting. The LT3083 is offered in the 16-lead

TSSOP (with an exposed pad for better thermal character-

istics), 12-lead 4mm × 4mm DFN (also with an exposed

pad), 5-lead TO-220, and 5-lead surface mount DD-PAK

packages.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

1.5V to 0.9V at 3A Supply (Using 3.3V V

CONTROL

)

FEATURES

APPLICATIONS

Outputs May be Paralleled for Higher Current and

Heat Spreading

Output Current: 3A

Single Resistor Programs Output Voltage

50µA Set Pin Current: 1% Initial Accuracy

Output Adjustable to 0V

Low Output Noise: 40µV

RMS

(10Hz to 100kHz)

Wide Input Voltage Range: 1.2V to 23V

(DD-Pak and TO-220 Packages)

Low Dropout Voltage: 310mV

<1mV Load Regulation

<0.001%/V Line Regulation

Minimum Load Current: 1mA

Stable with Minimum 10µF Ceramic Capacitor

Current Limit with Foldback and Overtemperature

Protection

Available in 16-Lead TSSOP, 12-Lead 4mm × 4mm

DFN, 5-Lead TO-220 and 5-Lead Surface Mount

DD-PAK Packages

High Current All Surface Mount Supply

High Efﬁciency Linear Regulator

Post Regulator for Switching Supplies

Low Parts Count Variable Voltage Supply

Low Output Voltage Power Supplies

Set Pin Current Distribution

3083 TA01b

49.5 50 50.5

SET PIN CURRENT DISTRIBUTION (µA)

N = 1052

3083 TA01a

CONTROL

OUTIN

LT3083

SET

MIN

909Ω

10µF

OUT

= 0.9V

MAX

= 3A

1.5V

4.7µF

CONTROL

3.3V

SET

18.2k

0.1µF

*OPTIONAL FOR

MINIMUM 1mA LOAD

REQUIREMENT

Summary of content (28 pages)

PAGE 1
LT3083 Adjustable 3A Single Resistor Low Dropout Regulator DESCRIPTION FEATURES n n n n n n n n n n n n n n Outputs May be Paralleled for Higher Current and Heat Spreading Output Current: 3A Single Resistor Programs Output Voltage 50µA Set Pin Current: 1% Initial Accuracy Output Adjustable to 0V Low Output Noise: 40µVRMS (10Hz to 100kHz) Wide Input Voltage Range: 1.2V to 23V (DD-Pak and TO-220 Packages) Low Dropout Voltage: 310mV <1mV Load Regulation <0.
PAGE 2
LT3083 ABSOLUTE MAXIMUM RATINGS (Note 1) All Voltages Relative to VOUT CONTROL Pin Voltage..............................................±28V IN Pin Voltage (T5, Q Packages).....................18V, –0.3V No Overload or Short-Circuit......................23V, –0.3V IN Pin Voltage (DF, FE Packages)......................8V, –0.3V No Overload or Short-Circuit......................14V, –0.3V SET Pin Current (Note 7)......................................±25mA SET Pin Voltage (Relative to OUT)....................
PAGE 3
LT3083 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3083IQ#PBF LT3083IQ#TRPBF LT3083Q 5-Lead Plastic DD-PAK –40°C to 125°C LT3083IT#PBF LT3083IT#TRPBF LT3083T 5-Lead Plastic TO-220 –40°C to 125°C LT3083MPDF#PBF LT3083MPDF#TRPBF 3083 12-Lead (4mm × 4mm) Plastic DFN –55°C to 125°C LT3083MPFE#PBF LT3083MPFE#TRPBF 3083FE 16-Lead Plastic TSSOP –55°C to 125°C LT3083MPQ#PBF LT3083MPQ#TRPBF LT3083Q 5-Lead Plastic DD-PAK –55°C to
PAGE 4
LT3083 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C (Note 2). PARAMETER CONDITIONS VCONTROL Dropout Voltage (Note 4) ILOAD = 100mA ILOAD = 1A ILOAD = 3A TYP MAX UNITS l l 1.2 1.22 1.25 1.55 1.
PAGE 5
LT3083 TYPICAL PERFORMANCE CHARACTERISTICS SET Pin Current TA = 25°C, unless otherwise noted. Set Pin Current Distribution 50.5 1.0 N = 1052 50.4 0.6 OFFSET VOLTAGE (mV) SET PIN CURRENT (µA) 50.2 50.1 50.0 49.9 49.8 0.2 0 –0.2 –0.4 –0.6 49.6 –0.8 49.5 –50 –25 0 49.5 50 50.5 SET PIN CURRENT DISTRIBUTION (µA) 49 25 50 75 100 125 150 TEMPERATURE (°C) –1.0 –50 –25 51 Offset Voltage Distribution 1.00 Offset Voltage (VOUT – VSET) Offset Voltage (VOUT – VSET) 0.25 ILOAD = 5mA 0.75 0 0.
PAGE 6
LT3083 TYPICAL PERFORMANCE CHARACTERISTICS Dropout Voltage, T/Q Packages (Minimum IN Voltage) Dropout Voltage, FE/DF Packages Dropout Voltage, FE/DF Packages (Minimum IN Voltage) 500 350 TJ = 125°C 300 250 TJ = 25°C 200 150 TJ = –50°C 100 50 0 0.5 1 1.5 2 LOAD CURRENT (A) 2.5 450 400 ILOAD = 3A 350 300 250 ILOAD = 1.5A 200 150 ILOAD = 500mA 100 3 50 ILOAD = 100mA 0 –50 –25 0 25 50 75 100 125 150 TEMPERATURE (°C) 3083 G10 350 ILOAD = 3A 300 250 ILOAD = 1.
PAGE 7
LT3083 TYPICAL PERFORMANCE CHARACTERISTICS 150 VIN = 2V 100 VCONTROL = 3V VOUT = 1V 50 CSET = 0.1µF COUT = 22µF CERAMIC 0 –50 LOAD CURRENT (A) Load Transient Response 250 LOAD CURRENT (A) OUTPUT VOLTAGE DEVIATION (mV) OUTPUT VOLTAGE DEVIATION (mV) Load Transient Response COUT = 10µF CERAMIC –100 1.0 0.5 0 ∆ILOAD = 100mA TO 1A 0 TA = 25°C, unless otherwise noted. VIN = 2V VCONTROL = 3V VOUT = 1V CSET = 0.
PAGE 8
LT3083 TYPICAL PERFORMANCE CHARACTERISTICS Ripple Rejection, Dual Supply, VCONTROL Pin Ripple Rejection, Single Supply ILOAD = 0.1A RIPPLE REJECTION (dB) RIPPLE REJECTION (dB) 80 70 60 50 ILOAD = 1.5A ILOAD = 0.5A 40 30 COUT = 10µF CERAMIC 20 CSET = 0.1µF CERAMIC 10 RIPPLE = 50mVP-P VIN – VCONTROL = VOUT(NOMINAL) + 2V 0 10 100 1k 10k 100k 1M FREQUENCY (Hz) Ripple Rejection, Dual Supply, IN Pin 120 120 105 105 ILOAD = 0.1A 90 RIPPLE REJECTION (dB) 100 90 TA = 25°C, unless otherwise noted.
PAGE 9
LT3083 PIN FUNCTIONS (DF/FE/Q/T Packages) OUT (Pins 1-5,13/Pins 1-6,8,9,16,17/ Pin 3, Tab/Pin 3, Tab): Output. The exposed pad of the DF package (Pin 13) and the FE package (Pin 17) and the Tab of the DD-PAK and TO-220 packages is an electrical connection to OUT. Connect the exposed pad of the DF and FE packages and the Tab of the DD-PAK package directly to OUT on the PCB and the respective OUT pins for each package. There must be a minimum load current of 1mA or the output may not regulate.
PAGE 10
LT3083 APPLICATIONS INFORMATION The LT3083 regulator is easy to use and has all the protection features expected in high performance regulators. Included are short-circuit protection and safe operating area protection, as well as thermal shutdown with hysteresis. The LT3083 fits well in applications needing multiple rails.
PAGE 11
LT3083 APPLICATIONS INFORMATION Table 1 lists many common output voltages and the closest standard 1% resistor values used to generate that output voltage. OUT Regulation of the output voltage requires a minimum load current of 1mA. For a true zero voltage output operation, return this 1mA load current to a negative supply voltage. Table 1. 1% Resistors for Common Output Voltages VOUT (V) RSET (k) 1 20 1.2 24.3 1.5 30.1 1.8 35.7 2.5 49.9 3.3 66.
PAGE 12
LT3083 APPLICATIONS INFORMATION When longer supply lines, filters, current sense resistors, or other impedances exist between the supply and the input to the LT3083, input bypassing should be reviewed if stability concerns are seen. Just as output capacitance supplies the instantaneous changes in load current for output transients until the regulator is able to respond, input capacitance supplies local power to the regulator until the main supply responds.
PAGE 13
LT3083 APPLICATIONS INFORMATION 20 effective value as low as 1μF to 2μF for the DC bias voltage applied and over the operating temperature range. The X5R and X7R dielectrics result in more stable characteristics and are more suitable for use as the output capacitor. The X7R type has better stability across temperature, while the X5R is less expensive and is available in higher values. Care still must be exercised when using X5R and X7R capacitors.
PAGE 14
LT3083 APPLICATIONS INFORMATION resistance of 10mΩ (5mΩ for the two devices in parallel) only adds about 30mV of output regulation drop at an output of 6A. With an output voltage of 3.3V, this only adds 1% to the regulation. Of course, paralleling more than two LT3083s yields even higher output current. Spreading the devices on the PC board also spreads the heat. Series input resistors can further spread the heat if the input-to-output difference is high.
PAGE 15
LT3083 APPLICATIONS INFORMATION Thermal Considerations Table 4. FE Package, 16-Lead TSSOP The LT3083’s internal power and thermal limiting circuitry protects itself under overload conditions. For continuous normal load conditions, do not exceed the 125°C maximum junction temperature. Carefully consider all sources of thermal resistance from junction-to-ambient.
PAGE 16
LT3083 APPLICATIONS INFORMATION The power in the drive circuit equals: PDRIVE = (VCONTROL – VOUT)(ICONTROL) where ICONTROL is equal to IOUT/60. ICONTROL is a function of output current. A curve of ICONTROL vs IOUT can be found in the Typical Performance Characteristics curves. The total power equals: PTOTAL = PDRIVE + POUTPUT The current delivered to the SET pin is negligible and can be ignored. VCONTROL(MAX_CONTINUOUS) = 3.630V (3.3V + 10%) VIN(MAX_CONTINUOUS) = 1.575V (1.5V + 5%) VOUT = 0.
PAGE 17
LT3083 APPLICATIONS INFORMATION The second technique for reducing power dissipation, shown in Figure 8, uses a resistor in parallel with the LT3083. This resistor provides a parallel path for current flow, reducing the current flowing through the LT3083. This technique works well if input voltage is reasonably constant and output load current changes are small. This technique also increases the maximum available output current at the expense of minimum load requirements. C1 Calculating RP yields: 5.5V − 3.
PAGE 18
LT3083 TYPICAL APPLICATIONS Adding Shutdown LT3083 IN VIN Current Source VCONTROL VCONTROL + – + – 10µF OUT Q1 VN2222LL OUT 0.33Ω VOUT SET ON OFF LT3083 IN VIN 10V SET 10µF Q2* VN2222LL R1 SHUTDOWN IOUT 0A TO 3A 20k 3083 TA03 3083 TA02 *Q2 INSURES ZERO OUTPUT IN THE ABSENCE OF ANY OUTPUT LOAD.
PAGE 19
LT3083 TYPICAL APPLICATIONS Coincident Tracking LT3083 IN VCONTROL LT3083 IN + – VCONTROL LT3083 IN VIN 7V TO 20V + – VCONTROL + – C1 10µF SET SET R1 49.9k 34k OUT SET R2 16.2k OUT OUT VOUT3 5V 10µF 3083 TA06 VOUT2 3.3V C3 10µF VOUT1 2.5V C2 10µF Adding Soft-Start LT3083 IN VIN 4.8V to 20V VCONTROL + – D1 1N4148 C1 10µF OUT SET C2 0.01µF VOUT 3.3V 3A COUT 10µF R1 66.5k 3083 TA07 Lab Supply LT3083 IN VIN 12V TO 18V VCONTROL VCONTROL + LT3083 IN + – 15µF + – OUT 0.
PAGE 20
LT3083 TYPICAL APPLICATIONS High Voltage Regulator 6.1V 10k VIN 50V 1N4148 IN LT3083 BUZ11 VCONTROL + + – 10µF 15µF VOUT 3A OUT SET RSET 402k + VOUT = 20V VOUT = 50µA • RSET 10µF 3083 TA09 Ramp Generator LT3083 IN VIN 5V Reference Buffer VCONTROL VCONTROL + – 10µF + – OUT VOUT SET VN2222LL LT3083 IN VIN 10µF VN2222LL 10nF INPUT LT1019 OUTPUT SET C1 1µF GND OUT VOUT* C2 10µF 3083 TA11 *MIN LOAD 0.
PAGE 21
LT3083 TYPICAL APPLICATIONS Low Voltage, High Current Adjustable High Efficiency Regulator* 0.47µH PVIN 2.7V TO 5.5V† 2× 100µF + ITH SVIN 2.2MEG 100k 10k SW LTC3610 RT + 12.1k 470pF 294k PGOOD 2× 100µF 2N3906 LT3083 IN VCONTROL RUN/SS + – VFB 1000pF OUT 78.7k SGND PGND 10mΩ SET SYNC/MODE 124k LT3083 IN VCONTROL + – *DIFFERENTIAL VOLTAGE ON LT3083 IS 0.6V SET BY THE VBE OF THE 2N3906 PNP. OUT †MAXIMUM OUTPUT VOLTAGE IS 1.
PAGE 22
LT3083 TYPICAL APPLICATIONS Adjustable High Efficiency Regulator* 4.5V TO 25V† VIN 10µF 1µF BOOST 0.47µF BD LT3680 100k RUN/SS 4.7µH 0.1µF 68µF B340A 680pF RT 63.4k GND VCONTROL TP0610L VCONTROL 15.4k LT3083 IN SW FB + – 200k OUT 10k SET 600kHz 3083 TA14 0V TO 10V† 3A 4.7µF 200k *DIFFERENTIAL VOLTAGE ON LT3083 ≈ 1.4V SET BY THE TPO610L P-CHANNEL THRESHOLD.
PAGE 23
LT3083 PACKAGE DESCRIPTION FE Package 16-Lead Plastic TSSOP (4.4mm) FELTC Package (Reference DWG # 05-08-1663 Rev H) 16-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG #Pad 05-08-1663 Exposed VariationRev BB H) Exposed Pad Variation BB 4.90 – 5.10* (.193 – .201) 3.58 (.141) 3.58 (.141) 16 1514 13 12 1110 6.60 ±0.10 4.50 ±0.10 9 2.94 (.116) 2.94 6.40 (.116) (.252) BSC SEE NOTE 4 0.45 ±0.05 1.05 ±0.10 0.65 BSC 1 2 3 4 5 6 7 8 RECOMMENDED SOLDER PAD LAYOUT 4.30 – 4.50* (.169 – .177) 0.09 – 0.20 (.
PAGE 24
LT3083 PACKAGE DESCRIPTION DF Package 12-Lead Plastic DFN (4mm × 4mm) (Reference LTC DWG # 05-08-1733 Rev Ø) 2.50 REF 0.70 ±0.05 3.38 ±0.05 4.50 ± 0.05 3.10 ± 0.05 2.65 ± 0.05 PACKAGE OUTLINE 0.25 ±0.05 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ± 0.10 (4 SIDES) 2.50 REF 7 12 0.40 ± 0.10 3.38 ±0.10 2.65 ± 0.10 PIN 1 NOTCH R = 0.20 TYP OR 0.35 × 45° CHAMFER PIN 1 TOP MARK (NOTE 6) 0.200 REF 6 R = 0.115 TYP 0.75 ± 0.
PAGE 25
LT3083 PACKAGE DESCRIPTION Q Package Q Package 5-Lead Plastic DDDD-PAK Pak 5-Lead Plastic (Reference LTCLTC DWG # 05-08-1461 Rev E)E) (Reference DWG # 05-08-1461 Rev .256 (6.502) .060 (1.524) TYP .060 (1.524) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .045 – .055 (1.143 – 1.397) 15° TYP .060 (1.524) .183 (4.648) +.008 .004 –.004 +0.203 0.102 –0.102 .059 (1.499) TYP .330 – .370 (8.382 – 9.398) ( ) .095 – .115 (2.413 – 2.921) .075 (1.905) .300 (7.620) +.012 .143 –.020 +0.305 3.
PAGE 26
LT3083 PACKAGE DESCRIPTION T Package 5-Lead Plastic TO-220 (Standard) (Reference LTC DWG # 05-08-1421) .390 – .415 (9.906 – 10.541) .165 – .180 (4.191 – 4.572) .147 – .155 (3.734 – 3.937) DIA .045 – .055 (1.143 – 1.397) .230 – .270 (5.842 – 6.858) .460 – .500 (11.684 – 12.700) .570 – .620 (14.478 – 15.748) .330 – .370 (8.382 – 9.398) .700 – .728 (17.78 – 18.491) .620 (15.75) TYP SEATING PLANE .152 – .202 .260 – .320 (3.861 – 5.131) (6.60 – 8.13) BSC .067 (1.70) .095 – .115 (2.413 – 2.921) .
PAGE 27
LT3083 REVISION HISTORY REV DATE DESCRIPTION PAGE NUMBER A 4/11 Revised part markings in Order Information section 3 3083fa 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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PAGE 28
LT3083 TYPICAL APPLICATION Paralleling Regulators IN LT3083 VCONTROL + – OUT 10mΩ SET IN VIN 4.8V TO 28V LT3083 VCONTROL + – 10µF OUT 10mΩ VOUT 3.3V 6A SET 33.2k 22µF 3083 TA16 RELATED PARTS PART NUMBER LT1185 LT1764/ LT1764A LT1963/A LT1965 LT3022 DESCRIPTION 3A Negative Low Dropout Regulator 3A, Fast Transient Response, Low Noise LDO 1.5A Low Noise, Fast Transient Response LDO 1.