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LT3027

3027fa

OUT

100µV/DIV

20µV

RMS

3027 TA01b

APPLICATIO S

DESCRIPTIO

FEATURES

TYPICAL APPLICATIO

Dual 100mA,

Low Dropout, Low Noise,

Micropower Regulator with

Independent Inputs

■

Low Noise: 20µV

RMS

(10Hz to 100kHz)

■

Low Quiescent Current: 25µA/Channel

■

Independent Inputs

■

Wide Input Voltage Range: 1.8V to 20V

■

Output Current: 100mA/Channel

■

Very Low Shutdown Current: <0.1

■

Low Dropout Voltage: 300mV at 100mA

■

Adjustable Output from 1.22V to 20V

■

Stable with 1µF Output Capacitor

■

Stable with Aluminum, Tantalum or

Ceramic Capacitors

■

Reverse Battery Protected

■

No Protection Diodes Needed

■

Overcurrent and Overtemperature Protected

■

Tracking/Sequencing Capability

■

Thermally Enhanced 10-Lead MSOP and DFN

Packages

The LT

3027 is a dual, micropower, low noise, low drop-

out regulator with independent inputs. With an external

0.01µF bypass capacitor, output noise is a low 20µV

RMS

over a 10Hz to 100kHz bandwidth. Designed for use in

battery-powered systems, the low 25µA quiescent current

per channel makes it an ideal choice. In shutdown, quies-

cent current drops to less than 0.1µA. Shutdown control

is independent for each channel, allowing for flexibility in

power management. The device is capable of operating

over an input voltage from 1.8V to 20V, and can supply

100mA of output current from each channel with a drop-

out voltage of 300mV. Quiescent current is well controlled

in dropout.

The LT3027 regulator is stable with output capacitors as

low as 1µF. Small ceramic capacitors can be used without

the series resistance required by other regulators.

Internal protection circuitry includes reverse battery pro-

tection, current limiting and thermal limiting protection.

The device is available as an adjustable device with a

1.22V reference voltage. The LT3027 regulator is available

in the thermally enhanced 10-lead MSOP and low profile

(0.75mm) 3mm × 3mm DFN packages.

10Hz to 100kHz Output Noise

3.3V/2.5V Low Noise Regulators

■

Cellular Phones

■

Pagers

■

Battery-Powered Systems

■

Frequency Synthesizers

■

Wireless Modems

■

Tracking/Sequencing Power Supplies

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

IN1

0.01µF

10µF

3027 TA01

OUT1

IN1

3.7V TO

20V

BYP1

ADJ1

OUT2

BYP2

ADJ2

GND

LT3027

3.3V AT 100mA

20µV

RMS

NOISE

2.5V AT 100mA

20µV

RMS

NOISE

1µF

SHDN1

IN2

2.9V TO

20V

1µF

SHDN2

10µF

422k

249k

261k

249k

All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 6118263, 6144250.

Summary of content (16 pages)

PAGE 1
LT3027 Dual 100mA, Low Dropout, Low Noise, Micropower Regulator with Independent Inputs U FEATURES DESCRIPTIO ■ The LT ®3027 is a dual, micropower, low noise, low dropout regulator with independent inputs. With an external 0.01µF bypass capacitor, output noise is a low 20µVRMS over a 10Hz to 100kHz bandwidth. Designed for use in battery-powered systems, the low 25µA quiescent current per channel makes it an ideal choice. In shutdown, quiescent current drops to less than 0.1µA.
PAGE 2
LT3027 W W W AXI U U ABSOLUTE RATI GS (Note 1) IN1, IN2 Pin Voltage .............................................. ±20V OUT1, OUT2 Pin Voltage ....................................... ±20V Input to Output Differential Voltage ....................... ±20V ADJ1, ADJ2 Pin Voltage ......................................... ±7V BYP1, BYP2 Pin Voltage ....................................... ±0.6V SHDN1, SHDN2 Pin Voltage ................................. ±20V Output Short-Circut Duration ....................
PAGE 3
LT3027 ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. (Note 2) PARAMETER CONDITIONS MIN GND Pin Current (Per Channel) VIN = VOUT(NOMINAL) (Notes 5, 7) ILOAD = 0mA ILOAD = 1mA ILOAD = 10mA ILOAD = 50mA ILOAD = 100mA Output Voltage Noise COUT = 10µF, CBYP = 0.
PAGE 4
LT3027 U W TYPICAL PERFOR A CE CHARACTERISTICS 500 450 450 400 400 TJ = 125°C 300 250 TJ = 25°C 200 150 500 = TEST POINTS 450 DROPOUT VOLTAGE (mV) 500 350 TJ ≤ 125°C 350 300 TJ ≤ 25°C 250 200 150 350 250 150 50 50 50 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 3027 G01 30 IL = 1mA 20 15 10 5 1.230 1.225 1.220 1.215 1.210 VSHDN = 0V 0 25 50 75 100 125 1.200 –50 –25 TEMPERATURE (°C) 25 50 75 100 0 125 RL = 24.4Ω IL = 50mA* 0.75 RL = 1.22k IL = 1mA* 0.
PAGE 5
LT3027 U W TYPICAL PERFOR A CE CHARACTERISTICS 0.9 IL = 100mA 0.7 0.6 IL = 1mA 0.5 0.4 0.3 0.2 1.4 VSHDN = 20V SHDN PIN INPUT CURRENT (µA) 1.0 0.9 SHDN PIN INPUT CURRENT (µA) SHDN PIN THRESHOLD (V) 1.0 0.8 SHDN1 or SHDN2 Pin Input Current SHDN1 or SHDN2 Pin Input Current SHDN1 or SHDN2 Pin Threshold (Off-to-On) 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.1 0 –50 –25 0 50 25 0 75 TEMPERATURE (°C) 100 0 125 1 2 3 4 5 6 7 8 SHDN PIN VOLTAGE (V) 9 100 0.4 0.
PAGE 6
LT3027 U W TYPICAL PERFOR A CE CHARACTERISTICS Input Ripple Rejection Channel-to-Channel Isolation Channel-to-Channel Isolation 80 CHANNEL-TO-CHANNEL ISOLATION (dB) 100 RIPPLE REJECTION (dB) 70 VOUT1 20mV/DIV 60 50 40 VOUT2 20mV/DIV 30 20 10 VIN = VOUT (NOMINAL) + 1V + 0.5VP-P RIPPLE AT f = 120Hz IL = 50mA 0 –50 –25 0 25 50 75 100 50µs/DIV COUT1, COUT2 = 10µF CBYP1, CBYP2 = 0.
PAGE 7
LT3027 U W TYPICAL PERFOR A CE CHARACTERISTICS RMS Output Noise vs Load Current (10Hz to 100kHz) 160 COUT = 10µF CBYP = 0µF CBYP = 0.01µF 120 VOUT SET FOR 5V VOUT 100µV/DIV VOUT 100µV/DIV 100 80 VOUT =VADJ 60 40 VOUT SET FOR 5V 20 0.1 1 10 LOAD CURRENT (mA) 3027 G28 1ms/DIV COUT = 10µF IL = 100mA VOUT SET FOR 5V OUT VOUT =VADJ 100 1ms/DIV COUT = 10µF IL = 100mA VOUT SET FOR 5V OUT 3027 G29 3027 G27 10Hz to 100kHz Output Noise CBYP = 1000pF 10Hz to 100kHz Output Noise CBYP = 0.
PAGE 8
LT3027 U U U PI FU CTIO S ADJ1/ADJ2 (Pins 4/2): Adjust Pin. These are the inputs to the error amplifiers. These pins are internally clamped to ±7V. They have a bias current of 30nA which flows into the pin (see curve of ADJ1/ADJ2 Pin Bias Current vs Temperature in the Typical Performance Characteristics section). The ADJ1 and ADJ2 pin voltage is 1.22V referenced to ground and the output voltage range is 1.22V to 20V. BYP1/BYP2 (Pins 5/1): Bypass.
PAGE 9
LT3027 U W U U APPLICATIO S I FOR ATIO The LT3027 is a dual 100mA low dropout regulator with independent inputs, micropower quiescent current and shutdown. The device is capable of supplying 100mA per channel at a dropout voltage of 300mV. Output voltage noise can be lowered to 20µVRMS over a 10Hz to 100kHz bandwidth with the addition of a 0.01µF reference bypass capacitor.
PAGE 10
LT3027 U W U U APPLICATIO S I FOR ATIO The LT3027 regulator is designed to be stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. A minimum output capacitor of 1µF with an ESR of 3Ω or less is recommended to prevent oscillations. The LT3027 is a micropower device and output transient response will be a function of output capacitance.
PAGE 11
LT3027 U W U U APPLICATIO S I FOR ATIO Voltage and temperature coefficients are not the only sources of problems. Some ceramic capacitors have a piezoelectric response. A piezoelectric device generates voltage across its terminals due to mechanical stress, similar to the way a piezoelectric accelerometer or microphone works. For a ceramic capacitor the stress can be induced by vibrations in the system or thermal transients.
PAGE 12
LT3027 U W U U APPLICATIONS INFORMATION The power dissipated by each channel of the device will be equal to: IOUT(MAX)(VIN(MAX) – VOUT) + IGND(VIN(MAX)) where (for the first channel): IOUT(MAX) = 100mA VIN(MAX) = 6V IGND at (IOUT = 100mA, VIN = 6V) = 2mA so: P1 = 100mA(6V – 3.3V) + 2mA(6V) = 0.28W and (for the second channel): IOUT(MAX) = 50mA VIN(MAX) = 6V IGND at (IOUT = 50mA, VIN = 6V) = 1mA so: P2 = 50mA(6V – 2.5V) + 1mA(6V) = 0.
PAGE 13
LT3027 U TYPICAL APPLICATIO S Noise Bypassing Slows Startup, Allows Outputs to Track VSHDN1/SHDN2 1V/DIV VIN1 3.7V TO 20V VOUT1 1V/DIV VOUT2 1V/DIV 10µF 0.01µF BYP1 VIN2 2.9V TO 20V 3.3V AT 100mA OUT1 IN1 1µF 422k 249k IN2 LT3027 Startup Time 1µF 10µF 0.01µF 261k BYP2 SHDN2 GND ADJ2 STARTUP TIME (ms) SHDN1 100 2.5V AT 100mA OUT2 OFF ON 3027 TA02b 2ms/DIV ADJ1 249k 3027 TA02a 10 1 0.
PAGE 14
LT3027 U PACKAGE DESCRIPTIO DD Package 10-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1699) R = 0.115 TYP 6 0.38 ± 0.10 10 0.675 ±0.05 3.50 ±0.05 1.65 ±0.05 2.15 ±0.05 (2 SIDES) 3.00 ±0.10 (4 SIDES) PACKAGE OUTLINE 1.65 ± 0.10 (2 SIDES) PIN 1 TOP MARK (SEE NOTE 6) (DD10) DFN 1005 5 0.25 ± 0.05 0.200 REF 0.50 BSC 2.38 ±0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 1 0.75 ±0.05 0.00 – 0.05 0.25 ± 0.05 0.50 BSC 2.38 ±0.10 (2 SIDES) BOTTOM VIEW—EXPOSED PAD NOTE: 1.
PAGE 15
LT3027 U PACKAGE DESCRIPTIO MSE Package 10-Lead Plastic MSOP (Reference LTC DWG # 05-08-1663) BOTTOM VIEW OF EXPOSED PAD OPTION 2.794 ± 0.102 (.110 ± .004) 5.23 (.206) MIN 0.889 ± 0.127 (.035 ± .005) 1 2.06 ± 0.102 (.081 ± .004) 1.83 ± 0.102 (.072 ± .004) 2.083 ± 0.102 3.20 – 3.45 (.082 ± .004) (.126 – .136) 10 0.50 0.305 ± 0.038 (.0197) (.0120 ± .0015) BSC TYP RECOMMENDED SOLDER PAD LAYOUT 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 4.90 ± 0.152 (.193 ± .006) 0.
PAGE 16
LT3027 U TYPICAL APPLICATIO S Startup Sequencing VIN1 3.7V TO 20V 1µF 10µF 0.01µF BYP1 VIN2 2.9V TO 20V 3.3V AT 100mA OUT1 IN1 422k 35.7k 249k 28k Turn-On Waveforms Turn-Off Waveforms ADJ1 IN2 LT3027 1µF 2.5V AT 100mA OUT2 OFF ON 10µF 0.01µF SHDN1 BYP2 SHDN2 GND 261k VSHDN1 1V/DIV VSHDN1 1V/DIV VOUT1 1V/DIV VOUT2 1V/DIV VOUT1 1V/DIV VOUT2 1V/DIV ADJ2 0.