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LT3012B

3012bf

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Wide Input Voltage Range: 4V to 80V

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Low Quiescent Current: 40µA

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Low Dropout Voltage: 400mV

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Output Current: 250mA

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No Protection Diodes Needed

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Adjustable Output from 1.24V to 60V

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Stable with 3.3µF Output Capacitor

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Stable with Aluminum, Tantalum or Ceramic

Capacitors

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Reverse-Battery Protection

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No Reverse Current Flow from Output to Input

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Thermal Limiting

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Thermally Enhanced 16-Lead TSSOP and 12-Pin

(4mm × 3mm) DFN Packages

250mA, 4V to 80V

Low Dropout

Micropower Linear Regulator

5V Supply

Dropout Voltage

The LT

3012B is a high voltage, micropower low dropout

linear regulator. The device is capable of supplying 250mA

of output current with a dropout voltage of 400mV. De-

signed for use in battery-powered or high voltage sys-

tems, the low quiescent current (40µA operating) makes

the LT3012B an ideal choice. Quiescent current is also well

controlled in dropout.

Other features of the LT3012B include the ability to oper-

ate with very small output capacitors. The regulators are

stable with only 3.3µF on the output while most older

devices require between 10µF and 100µF for stability.

Small ceramic capacitors can be used without any need for

series resistance (ESR) as is common with other regula-

tors. Internal protection circuitry includes reverse-battery

protection, current limiting, thermal limiting and reverse

current protection.

The device is available with an adjustable output with a

1.24V reference voltage. The LT3012B regulator is avail-

able in the 16-lead TSSOP and 12 pin low profile (0.75mm)

(4mm × 3mm) DFN packages with an exposed pad for

enhanced thermal handling capability.

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Low Current High Voltage Regulators

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Regulator for Battery-Powered Systems

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Telecom Applications

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Automotive Applications

FEATURES

DESCRIPTIO

APPLICATIO S

TYPICAL APPLICATIO

, LTC and LT are registered trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

1µF

5.4V TO

80V

3012B TA01

OUT

250mA

3.3µF

750k

249k

LT3012B

OUT

ADJ

GND

OUTPUT CURRENT (mA)

250

300

400

350

200

3012B TA02

200

150

50 100 150 250

100

DROPOUT VOLTAGE (mV)

Summary of content (16 pages)

PAGE 1
LT3012B 250mA, 4V to 80V Low Dropout Micropower Linear Regulator U FEATURES DESCRIPTIO ■ The LT®3012B is a high voltage, micropower low dropout linear regulator. The device is capable of supplying 250mA of output current with a dropout voltage of 400mV. Designed for use in battery-powered or high voltage systems, the low quiescent current (40µA operating) makes the LT3012B an ideal choice. Quiescent current is also well controlled in dropout.
PAGE 2
LT3012B W W W AXI U U ABSOLUTE RATI GS (Note 1) IN Pin Voltage ................................................... ±80V OUT Pin Voltage ............................................... ±60V IN to OUT Differential Voltage ........................... ±80V ADJ Pin Voltage .................................................. ±7V Output Short-Circuit Duration ..................... Indefinite Storage Temperature Range TSSOP Package ........................... –65°C to 150°C DFN Package ......................
PAGE 3
LT3012B ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TJ = 25°C. PARAMETER CONDITIONS Dropout Voltage VIN = VOUT(NOMINAL) ILOAD = 10mA ILOAD = 10mA MIN ● (Notes 4, 5) ILOAD = 50mA ILOAD = 50mA ● ILOAD = 250mA ILOAD = 250mA ● ● TYP MAX UNITS 160 230 300 mV mV 250 340 420 mV mV 400 490 620 mV mV 40 3 10 100 µA mA mA GND Pin Current VIN = 4.
PAGE 4
LT3012B U W TYPICAL PERFOR A CE CHARACTERISTICS Typical Dropout Voltage Guaranteed Dropout Voltage 600 400 TJ = 25°C 300 200 100 0 TJ ≤ 125°C 500 500 400 DROPOUT VOLTAGE (mV) TJ = 125°C = TEST POINTS TJ ≤ 25°C 300 200 100 100 150 200 OUTPUT CURRENT (mA) 0 250 50 150 100 200 OUTPUT CURRENT (mA) Quiescent Current 50 40 30 20 0 50 75 25 TEMPERATURE (°C) 100 125 IL = 1mA 1.250 1.245 1.240 1.235 1.230 10 0 50 75 25 TEMPERATURE (°C) 100 RL = 1.
PAGE 5
LT3012B U W TYPICAL PERFOR A CE CHARACTERISTICS Current Limit 45 900 40 800 35 30 25 20 15 300 0 125 TJ = 125°C 400 100 100 TJ = 25°C 500 5 50 75 25 TEMPERATURE (°C) 600 600 200 0 VOUT = 0V 700 10 0 – 50 – 25 Current Limit 700 CURRENT LIMIT (mA) 1000 CURRENT LIMIT (mA) ADJ PIN BIAS CURRENT (nA) ADJ Pin Bias Current 50 10 0 20 30 40 50 60 INPUT VOLTAGE (V) 120 ADJ PIN CLAMP (SEE APPLICATIONS INFORMATION) 40 20 2 3 4 5 6 7 8 OUTPUT VOLTAGE (V) 9 30 25 20 15 10 5 75 50 25
PAGE 6
LT3012B U W TYPICAL PERFOR A CE CHARACTERISTICS Load Regulation 0 COUT = 3.3µF ILOAD = 250mA –2 LOAD REGULATION (mV) OUTPUT NOISE SPECTRAL DENSITY (µV/√Hz) Output Noise Spectral Density 10 1 0.1 ∆IL = 1mA TO 250mA –4 –6 –8 –10 –12 –14 –16 –18 0.01 10 100 1k 10k FREQUENCY (Hz) –20 – 50 – 25 100k 75 50 25 TEMPERATURE (°C) 0 100 3012B G22 125 3012B G21 10Hz to 100kHz Output Noise Transient Response VOUT 100µV/DIV COUT = 10µF IL = 250mA VOUT = 1.
PAGE 7
LT3012B U U U PI FU CTIO S (DFN Package)/(TSSOP Package) OUT (Pins 2, 3)/(Pins 3, 4): Output. The output supplies power to the load. A minimum output capacitor of 3.3µF is required to prevent oscillations. Larger output capacitors will be required for applications with large transient loads to limit peak voltage transients. See the Applications Information section for more information on output capacitance and reverse output characteristics. ADJ (Pin 4)/(Pin 5): Adjust.
PAGE 8
LT3012B U W U U APPLICATIO S I FOR ATIO The LT3012B is a 250mA high voltage low dropout regulator with micropower quiescent current. The device is capable of supplying 250mA at a dropout voltage of 400mV. Operating quiescent current is only 40µA. In addition to the low quiescent current, the LT3012B incorporates several protection features which make it ideal for use in battery-powered systems. The device is protected against both reverse input and reverse output voltages.
PAGE 9
LT3012B U W U U APPLICATIO S I FOR ATIO can exhibit an 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.
PAGE 10
LT3012B U W U U APPLICATIO S I FOR ATIO The LT3012B has internal thermal limiting designed to protect the device during overload conditions. For continuous normal conditions the maximum junction temperature rating of 125°C must not be exceeded. It is important to give careful consideration to all sources of thermal resistance from junction to ambient. Additional heat sources mounted nearby must also be considered.
PAGE 11
LT3012B U W U U APPLICATIO S I FOR ATIO The maximum junction temperature will then be equal to the maximum junction temperature rise above ambient plus the maximum ambient temperature or: TJMAX = 50°C + 65.5°C = 115.
PAGE 12
LT3012B U W U U APPLICATIO S I FOR ATIO In situations where the ADJ pin is connected to a resistor divider that would pull the ADJ pin above its 7V clamp voltage if the output is pulled high, the ADJ pin input current must be limited to less than 5mA. For example, a resistor divider is used to provide a regulated 1.5V output from the 1.24V reference when the output is forced to 60V.
PAGE 13
LT3012B U TYPICAL APPLICATIO S LT3012B Automotive Application VIN 12V (LATER 42V) IN + 1µF NO PROTECTION DIODE NEEDED! OUT LT3012B 750k 3.3µF ADJ GND LOAD: CLOCK, SECURITY SYSTEM ETC 249k LT3012B Telecom Application VIN 48V (72V TRANSIENT) IN OUT LT3012B 1µF ADJ GND 750k NO PROTECTION DIODE NEEDED! + 3.3µF LOAD: SYSTEM MONITOR ETC – BACKUP BATTERY 249k 3012B TA05 Constant Brightness for Indicator LED over Wide Input Voltage Range RETURN IN 1µF OUT LT3012B 3.
PAGE 14
LT3012B U PACKAGE DESCRIPTIO DE/UE Package 12-Lead Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1695 Rev C) 0.70 ±0.05 3.60 ±0.05 1.70 ±0.05 2.20 ±0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ± 0.05 3.30 ±0.05 (2 SIDES) 0.50 BSC RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 4.00 ±0.10 (2 SIDES) 7 R = 0.115 TYP 0.40 ± 0.10 12 R = 0.05 TYP PIN 1 TOP MARK (NOTE 6) 0.200 REF 3.00 ±0.10 (2 SIDES) 1.70 ± 0.05 (2 SIDES) PIN 1 NOTCH R = 0.20 OR 0.35 × 45° CHAMFER 0.75 ±0.05 0.00 – 0.05 6 0.25 ± 0.05 3.
PAGE 15
LT3012B U PACKAGE DESCRIPTIO FE Package 16-Lead Plastic TSSOP (4.4mm) (Reference LTC DWG # 05-08-1663) 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 9 2.94 (.116) 4.50 ±0.10 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 (.0035 – .0079) 0.50 – 0.75 (.020 – .030) NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2.
PAGE 16
LT3012B RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1020 125mA, Micropower Regulator and Comparator VIN: 4.5V to 36V, VOUT(MIN) = 2.5V, VDO = 0.4V, IQ = 40µA, ISD = 40µA, Comparator and Reference, Class B Outputs, S16, PDIP14 Packages LT1120/LT1120A 125mA, Micropower Regulator and Comparator VIN: 4.5V to 36V, VOUT(MIN) = 2.5V, VDO = 0.