Datasheet

ManualsBrandsLINEAR TECHNOLOGY ManualsPMICsPMIC - LDO voltage regulator Positivbe, adjustable DFN 16 (4x3)

LT3029

3029fb

For more information www.linear.com/LT3029

Typical applicaTion

FeaTures

applicaTions

DescripTion

Dual 500mA/500mA

Low Dropout, Low Noise,

Micropower Linear Regulator

The LT

3029 is a dual, micropower, low noise, low drop-

out linear regulator. The device operates either with a

common input supply or independent input supplies for

each channel, over an input voltage range of 1.8V to 20V.

Each output supplies up to 500mA of output current with

a typical dropout voltage of 300mV

. Quiescent current is

well controlled in dropout. With an external 10nF bypass

capacitor, output noise is only 20µV

RMS

over a 10Hz to

100kHz bandwidth. Designed for use in battery-powered

systems, the low 55µA quiescent current per channel

makes it an ideal choice. In shutdown, quiescent current

drops to less than 1µA. Shutdown control is independent

for each channel, allowing for ﬂexible power management.

The LT3029 optimizes stability and transient response with

low ESR ceramic output capacitors, requiring a minimum

of only 3.3µF. The regulator does not require the addition

of ESR, as is common with other regulators.

Internal circuitry provides reverse-battery protection,

reverse-current protection, current limiting with foldback

and thermal shutdown. The device is available as an

adjustable output voltage device with a 1.215V reference

voltage. The LT3029 is offered in the thermally enhanced

16-lead MSOP and 16-lead, low proﬁle (4mm × 3mm ×

0.75mm) DFN packages.

2.5V

to 1.5V/1.8V Application

Output Current: 500mA per Channel

Low Dropout Voltage: 300mV

Low Noise: 20µV

RMS

(10Hz to 100kHz)

Low Quiescent Current: 55µA per Channel

Wide Input Voltage Range: 1.8V to 20V (Common or

Independent Input Supply)

Adjustable Output: 1.215V Reference Voltage

Very Low Quiescent Current in Shutdown: <1µA per

Channel

Stable with 3.3µF Minimum Output Capacitor

Stable with Ceramic, Tantalum or Aluminum

Electrolytic Capacitors

Reverse-Battery and Reverse Output-to-Input

Protection

Current Limit with Foldback and Thermal Shutdown

Tracking/Sequencing Capability: Compatible with

LTC292X Power Supply Tracking ICs

Thermally Enhanced 16-Lead MSOP and 16-Lead

(4mm × 3mm) DFN Packages

General Purpose Linear Regulator

Battery-Powered Systems

Microprocessor Core/Logic Supplies

Post Regulator for Switching Supplies

Tracking/Sequencing Power Supplies

Dropout Voltage vs Load Current

OUT1

1.8V

500mA

OUT2

1.5V

500mA

237k

10nF

3.3µF

113k

3029 TA01

OUT2

ADJ2

BYP2

GND

237k

10nF

3.3µF

54.9k

OUT1

ADJ1

BYP1

LT3029

IN1

2.5V

3.3µF

SHDN1

IN2

SHDN2

OUTPUT CURRENT (mA)

DROPOUT VOLTAGE (mV)

400

350

300

250

200

150

100

400

3029 TA01b

100

200

300

500

50 450

150

250

350

= 25°C

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

ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property

of their respective owners.

Summary of content (20 pages)

PAGE 1
LT3029 Dual 500mA/500mA Low Dropout, Low Noise, Micropower Linear Regulator Description Features n n n n n n n n n n n n n Output Current: 500mA per Channel Low Dropout Voltage: 300mV Low Noise: 20µVRMS (10Hz to 100kHz) Low Quiescent Current: 55µA per Channel Wide Input Voltage Range: 1.8V to 20V (Common or Independent Input Supply) Adjustable Output: 1.215V Reference Voltage Very Low Quiescent Current in Shutdown: <1µA per Channel Stable with 3.
PAGE 2
LT3029 Absolute Maximum Ratings (Note 1) IN1, IN2 Pin Voltage.................................................±22V OUT1, OUT2 Pin Voltage..........................................±22V Input-to-Output Differential Voltage.........................±22V ADJ1, ADJ2 Pin Voltage.............................................±9V BYP1, BYP2 Pin Voltage.........................................±0.6V SHDN1 , SHDN2 Pin Voltage...................................±22V Output Short-Circuit Duration..........................
PAGE 3
LT3029 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 Minimum Input Voltage (Notes 3, 11) ILOAD = 500mA l ADJ1, ADJ2 Pin Voltage (Notes 3, 4, 9) VIN = 2V, ILOAD = 1mA 2.3V < VIN < 20V, 1mA < ILOAD < 500mA (E, I, MP) 2.3V < VIN < 20V, 1mA < ILOAD < 500mA (H) l l Line Regulation (Note 3) ∆VIN = 2V to 20V, ILOAD = 1mA l Load Regulation (Note 3) VIN = 2.
PAGE 4
LT3029 Electrical Characteristics Note 7: GND pin current is tested with VIN = 2.437V and a current source load. This means the device is tested while operating in its dropout region or at the minimum input voltage specification. This is the worst-case GND pin current. The GND pin current decreases slightly at higher input voltages. Total GND pin current equals the sum of output 1 and output 2 GND pin currents. Note 8: ADJ1/ADJ2 pin bias current flows into the pin.
PAGE 5
LT3029 Typical Performance Characteristics ADJ1 or ADJ2 Pin Voltage 1.239 Quiescent Current (per Channel) 160 IL = 1mA 1.233 TJ = 25°C RL = 243k VOUT = 1.215V 140 QUIESCENT CURRENT (µA) ADJ PIN VOLTAGE (V) TJ = 25°C, unless otherwise noted. 1.227 1.221 1.215 1.209 1.203 120 100 80 VSHDN = VIN 60 40 20 1.197 0 1.
PAGE 6
LT3029 Typical Performance Characteristics SHDN1 or SHDN2 Pin Input Current 1.0 1.0 0.9 0.9 SHDN PIN INPUT CURRENT (µA) SHDN PIN THRESHOLD (V) SHDN1 or SHDN2 Pin Threshold (Off-to-On) 0.8 0.7 IL = 500mA 0.6 0.5 IL = 1mA 0.4 0.3 0.2 TJ = 25°C, unless otherwise noted. TJ = 25°C 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.1 0 0 –75 –50 –25 0 25 50 75 100 125 150 175 TEMPERATURE (°C) 0 2 4 6 8 10 12 14 16 18 20 SHDN PIN VOLTAGE (V) 3029 G12 3029 G11 SHDN1 or SHDN2 Pin Input Current 1.
PAGE 7
LT3029 Typical Performance Characteristics Reverse Current 300 Input Ripple Rejection 100 VIN = 0V VADJ = VOUT = 1.215V 240 210 RIPPLE REJECTION (dB) REVERSE CURRENT (µA) 270 IADJ 180 150 120 90 60 30 TJ = 25°C 90 IL = 500mA +1V + 50mVRMS RIPPLE V =V 80 CIN = OUT(NOMINAL) BYP 0 COUT = 10µF 70 60 50 40 30 COUT = 3.3µF 20 10 IOUT 0 –75 –50 –25 0 TJ = 25°C, unless otherwise noted.
PAGE 8
LT3029 Typical Performance Characteristics Channel-to-Channel Isolation TJ = 25°C, unless otherwise noted. Load Regulation 0 –2 LOAD REGULATION (mV) VOUT1 50mV/DIV VOUT2 50mV/DIV –4 –6 –8 –10 –12 –14 –16 3029 G23 50µs/DIV ∆IL1 = 50mA TO 500mA COUT1 = 10µF COUT2 = 10µF ∆IL2 = 50mA TO 500mA CBYP1 = CBYP2 = 0.
PAGE 9
LT3029 Typical Performance Characteristics 10Hz to 100kHz Output Noise, CBYP = 0pF TJ = 25°C, unless otherwise noted. 10Hz to 100kHz Output Noise, CBYP = 100pF VOUT 100µV/DIV VOUT 100µV/DIV COUT = 10µF IL = 500mA VOUT = 5V 3029 G29 1ms/DIV COUT = 10µF IL = 500mA VOUT = 5V 10Hz to 100kHz Output Noise, CBYP = 1000pF 1ms/DIV 3029 G30 10Hz to 100kHz Output Noise, CBYP = 0.
PAGE 10
LT3029 Typical Performance Characteristics Transient Response, CBYP = 0pF TJ = 25°C, unless otherwise noted. Transient Response, CBYP = 0.01µF VOUT DEVIATION VOUT DEVIATION 50mV/DIV 200mV/DIV LOAD CURRENT DEVIATION LOAD CURRENT DEVIATION 250mA/DIV 250mA/DIV VIN = 6V CIN = 10µF COUT = 10µF 3029 G33 200µs/DIV IL = 100mA TJ = 25°C VOUT = 5V VIN = 6V CIN = 10µF COUT = 10µF Start-Up Time from Shutdown, CBYP = 0pF Start-Up Time from Shutdown, CBYP = 0.
PAGE 11
LT3029 Pin Functions BYP1/BYP2 (Pin 1/Pin 8): Bypass. Use the BYP1/BYP2 pins to bypass the reference of the LT3029 regulator and achieve low output noise performance. Internal circuitry clamps the BYP1/BYP2 pins to ±0.6V (one VBE) from ground. A small capacitor from the corresponding output to this pin bypasses the reference to lower the output voltage noise. Using a maximum value of 10nF reduces the output voltage noise to a typical 20µVRMS over a 10Hz to 100kHz bandwidth.
PAGE 12
LT3029 Applications Information The LT3029 is a dual 500mA/500mA low dropout regulator with independent inputs, micropower quiescent current and shutdown. The device supplies up to 500mA from each channel’s output at a typical dropout voltage of 300mV. The two regulators share a common GND pin and are thermally coupled. However, the two inputs and outputs of the LT3029 operate independently.
PAGE 13
LT3029 Applications Information Output Capacitance and Transient Response The LT3029 design is stable with a wide range of output capacitors. The ESR of the output capacitor affects stability, most notably with small capacitors. Linear Technology recommends a minimum output capacitor of 3.3µF with an ESR of 3Ω, or less, to prevent oscillations. The LT3029 is a micropower device, and output transient response is a function of output capacitance.
PAGE 14
LT3029 Applications Information Exercise care even when using X5R and X7R capacitors; the X5R and X7R codes only specify operating temperature range and maximum capacitance change over temperature. Capacitance change due to DC bias (voltage coefficient) with X5R and X7R capacitors is better than with Y5V and Z5U capacitors, but can still be significant enough to drop capacitor values below appropriate levels. Capacitor DC bias characteristics tend to improve as case size increases.
PAGE 15
LT3029 Applications Information Table 2. DE Package, 16-Lead DFN COPPER AREA THERMAL RESISTANCE BOARD AREA (JUNCTION-TO-AMBIENT) TOPSIDE* BACKSIDE 2500mm2 2500mm2 2500mm2 36°C/W 1000mm2 2500mm2 2500mm2 37°C/W 225mm2 2500mm2 2500mm2 38°C/W 100mm2 2500mm2 2500mm2 40°C/W *Device is mounted on topside. (0.37W + 0.52W) 39°C/W = 34.
PAGE 16
LT3029 Applications Information The LT3029 incurs no damage if either ADJ pin is pulled above or below ground by 9V. If the input is left open circuit or grounded, the ADJ pins perform like an open circuit down to –1.5V, and then like a 1.2k resistor down to –9V when pulled below ground. When pulled above ground, the ADJ pins perform like an open circuit up to 0.5V, then like a 5.7k resistor up to 3V, then like a 1.8k resistor up to 9V.
PAGE 17
LT3029 Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. DE Package 16-Lead Plastic DFN (4mm × 3mm) (Reference LTC DWG # 05-08-1732 Rev Ø) 0.70 ±0.05 3.30 ±0.05 3.60 ±0.05 2.20 ±0.05 1.70 ± 0.05 PACKAGE OUTLINE 0.25 ± 0.05 0.45 BSC 3.15 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 4.00 ±0.10 (2 SIDES) R = 0.05 TYP 9 R = 0.115 TYP 0.40 ± 0.10 16 3.30 ±0.10 3.00 ±0.
PAGE 18
LT3029 Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. MSE Package 16-Lead Plastic MSOP, Exposed Die Pad (Reference LTC DWG # 05-08-1667 Rev F) BOTTOM VIEW OF EXPOSED PAD OPTION 2.845 ±0.102 (.112 ±.004) 5.10 (.201) MIN 2.845 ±0.102 (.112 ±.004) 0.889 ±0.127 (.035 ±.005) 8 1 1.651 ±0.102 (.065 ±.004) 1.651 ±0.102 3.20 – 3.45 (.065 ±.004) (.126 – .136) 0.305 ±0.038 (.0120 ±.0015) TYP 16 0.50 (.0197) BSC 4.039 ±0.102 (.159 ±.
PAGE 19
LT3029 Revision History REV DATE DESCRIPTION PAGE NUMBER A 3/11 Added Overload Recovery section to Applications Information 16 B 4/14 Added H-grade to the DFN package 2 3029fb 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 20
LT3029 Typical Application Coincident Tracking Supply Application 3.3V 0.1µF VCC OFF ON CGATE 0.1µF 3.3V 3.3µF 63.4k 1% TRACK1 SDO 10nF BYP1 ADJ1 LT3029 1M IN2 3.3µF OUT2 BYP2 SHDN2 ADJ2 GND TRACK2 FB2 GND 113k 1% VOUT1 1.8V 3.3µF 500mA VOUT1 VOUT2 500mV/DIV 237k 1% SHDN1 2.5V 54.9k 1% OUT1 IN1 RAMP LTC2923 RAMPBUF FB1 113k 1% 90.9k 1% ON GATE 10nF 54.9k 1% VOUT2 3.3µF 1.