Texas Instruments LM2734 User Manual

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LM2734

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LM2734 Thin SOT 1A Load Step-Down DC-DC Regulator

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FEATURES

234

• Thin SOT-6 Package

• 3.0V to 20V Input Voltage Range

• 0.8V to 18V Output Voltage Range

• 1A Output Current

• 550kHz (LM2734Y) and 1.6MHz (LM2734X) Switching Frequencies

• 300mΩ NMOS Switch

• 30nA Shutdown Current

• 0.8V, 2% Internal Voltage Reference

• Internal Soft-Start

• Current-Mode, PWM Operation

• WEBENCH®Online Design Tool

• Thermal Shutdown

• LM2734XQ/LM2734YQ are AEC-Q100 Grade 1 Qualified and are Manufactured on an Automotive Grade Flow

APPLICATIONS

• Local Point of Load Regulation

• Core Power in HDDs

• Set-Top Boxes

• Battery Powered Devices

• USB Powered Devices

• DSL Modems

• Notebook Computers

• Automotive

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

DESCRIPTION

The LM2734 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in a 6-pin Thin SOT package. It provides all the active functions to provide local DC/DC conversion with fast transient response and accurate regulation in the smallest possible PCB area.

With a minimum of external components and online design support through WEBENCH®, the LM2734 is easy to use. The ability to drive 1A loads with an internal 300mΩ NMOS switch using state-of-the-art

0.5µm BiCMOS technology results in the best power density available. The world class control circuitry allows for on-times as low as 13ns, thus supporting exceptionally high frequency conversion over the entire 3V to 20V input operating range down to the minimum output voltage of 0.8V. Switching frequency is internally set to 550kHz (LM2734Y) or 1.6MHz (LM2734X), allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequencies are very high, efficiencies up to 90% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current of 30nA. The LM2734 utilizes current-mode control and internal compensation to provide highperformance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, and output over-voltage protection.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2WEBENCH is a registered trademark of Texas Instruments, Inc.. 3WEBENCH is a registered trademark of Texas Instruments. 4All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

BOOST

GND

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Typical Application Circuit

Figure 1. Figure 2. Efficiency vs Load Current

Connection Diagram

VIN= 5V, V

OUT

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= 3.3V

Figure 3. 6-Lead SOT Figure 4. Pin 1 Indentification

See Package Number DDC (R-PDSO-G6)

Pin Name Function

1 BOOST Boost voltage that drives the internal NMOS control switch. A bootstrap

2 GND Signal and Power ground pin. Place the bottom resistor of the feedback

3 FB Feedback pin. Connect FB to the external resistor divider to set output

4 EN Enable control input. Logic high enables operation. Do not allow this pin to

5 V 6 SW Output switch. Connects to the inductor, catch diode, and bootstrap

These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.

PIN DESCRIPTIONS

capacitor is connected between the BOOST and SW pins.

network as close as possible to this pin for accurate regulation.

voltage.

float or be greater than VIN+ 0.3V.

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Input supply voltage. Connect a bypass capacitor to this pin.

capacitor.

LM2734

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Absolute Maximum Ratings

(1)(2)

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

-0.5V to 24V SW Voltage -0.5V to 24V Boost Voltage -0.5V to 30V Boost to SW Voltage -0.5V to 6.0V FB Voltage -0.5V to 3.0V EN Voltage -0.5V to (VIN+ 0.3V) Junction Temperature 150°C ESD Susceptibility

(3)

2kV Storage Temp. Range -65°C to 150°C Soldering Information Reflow Peak Pkg. Temp.(15sec) 260°C

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is intended to be functional, but specific performance is not ensured. For specific specifications and the test conditions, see Electrical Characteristics.

(2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office/ Distributors for availability and

specifications.

(3) Human body model, 1.5kΩ in series with 100pF.

Operating Ratings

(1)

3V to 20V SW Voltage -0.5V to 20V Boost Voltage -0.5V to 25V Boost to SW Voltage 1.6V to 5.5V Junction Temperature Range −40°C to +125°C Thermal Resistance θ

(2)

118°C/W

(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for

which the device is intended to be functional, but specific performance is not ensured. For specific specifications and the test conditions, see Electrical Characteristics.

(2) Thermal shutdown will occur if the junction temperature exceeds 165°C. The maximum power dissipation is a function of T

and TA. The maximum allowable power dissipation at any ambient temperature is PD= (T packages soldered directly onto a 3” x 3” PC board with 2oz. copper on 4 layers in still air. For a 2 layer board using 1 oz. copper in still

– TA)/θJA. All numbers apply for

J(MAX)

, θ

air, θJA= 204°C/W.

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Electrical Characteristics

Specifications with standard typeface are for TJ= 25°C, and those in boldface type apply over the full Operating Temperature Range (TJ= -40°C to 125°C). VIN= 5V, V

specification limits are ensured by design, test, or statistical analysis.

Symbol Parameter Conditions Min

ΔVFB/ΔVINFeedback Voltage Line Regulation VIN= 3V to 20V 0.01 % / V

UVLO Undervoltage Lockout VINFalling 2.0 2.3 V

MAX

MIN

DS(ON)

BOOST

EN_TH

Feedback Voltage 0.784 0.800 0.816 V

Feedback Input Bias Current Sink/Source 10 250 nA Undervoltage Lockout VINRising 2.74 2.90

UVLO Hysteresis 0.30 0.44 0.62

Switching Frequency MHz

Maximum Duty Cycle %

Minimum Duty Cycle %

Switch ON Resistance V Switch Current Limit V Quiescent Current Switching 1.5 2.5 mA

LM2734X 1.2 1.6 1.9 LM2734Y 0.40 0.55 0.66 LM2734X 85 92 LM2734Y 90 96 LM2734X 2 LM2734Y 1

BOOST BOOST

Quiescent Current (shutdown) VEN= 0V 30 nA

Boost Pin Current mA

LM2734X (50% Duty Cycle) 2.5 3.5

LM2734Y (50% Duty Cycle) 1.0 1.8 Shutdown Threshold Voltage VENFalling 0.4 Enable Threshold Voltage VENRising 1.8 Enable Pin Current Sink/Source 10 nA Switch Leakage 40 nA

- VSW= 5V unless otherwise specified. Datasheet min/max

BOOST

(1)

Typ

(2)

Max

(1)

- VSW= 3V 300 600 mΩ

- VSW= 3V 1.2 1.7 2.5 A

Units

(1) Specified to Average Outgoing Quality Level (AOQL). (2) Typicals represent the most likely parametric norm.

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All curves taken at VIN= 5V, V

Efficiency vs Load Current - "X" V

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Typical Performance Characteristics

- VSW= 5V, L1 = 4.7 µH ("X"), L1 = 10 µH ("Y"), and TA= 25°C, unless specified

BOOST

= 5V Efficiency vs Load Current - "Y" V

OUT

Figure 5. Figure 6.

= 3.3V Efficiency vs Load Current - "Y" V

OUT

otherwise.

OUT

= 5V

= 3.3V

Figure 7. Figure 8.

Efficiency vs Load Current - "X" V

Figure 9. Figure 10.

= 1.5V Efficiency vs Load Current - "Y" V

OUT

Product Folder Links: LM2734

OUT

= 1.5V

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Typical Performance Characteristics (continued)

All curves taken at VIN= 5V, V otherwise.

Oscillator Frequency vs Temperature - "X" Oscillator Frequency vs Temperature - "Y"

Current Limit vs Temperature Current Limit vs Temperature

- VSW= 5V, L1 = 4.7 µH ("X"), L1 = 10 µH ("Y"), and TA= 25°C, unless specified

BOOST

Figure 11. Figure 12.

VIN= 5V VIN= 20V

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Figure 13. Figure 14.

VFBvs Temperature R

Figure 15. Figure 16.

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vs Temperature

DSON

LM2734

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All curves taken at VIN= 5V, V otherwise.

IQSwitching vs Temperature V

Line Regulation - "Y" Line Regulation - "X"

= 1.5V, I

OUT

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Typical Performance Characteristics (continued)

- VSW= 5V, L1 = 4.7 µH ("X"), L1 = 10 µH ("Y"), and TA= 25°C, unless specified

BOOST

Line Regulation - "X"

= 1.5V, I

OUT

Figure 17. Figure 18.

= 500mA V

OUT

= 3.3V, I

OUT

= 500mA

Figure 19. Figure 20.

Line Regulation - "Y"

OUT

= 3.3V, I

OUT

= 500mA

Figure 21.

Product Folder Links: LM2734

R 1

R 2

D 1

BOOST

Output Control

Logic

Current

Limit

Thermal

Shutdown

Under Voltage Lockout

Corrective Ramp

Reset Pulse

PWM Comparator

Current-Sense Amplifier

SENSE

Internal

Regulator

and

Enable

Circuit

Oscillator

Driver

0.3:

Switch

Internal

Compensation

GND

Error Amplifier

REF

0.8V

OUT

OFF

BOOST

OUT

SENSE

0.88V

OVP

Comparator

Error

Signal

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

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Block Diagram

Figure 22.

Product Folder Links: LM2734

Inductor

Current

D = TON/T

OFF

Voltage

LM2734

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SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

APPLICATION INFORMATION

THEORY OF OPERATION

The LM2734 is a constant frequency PWM buck regulator IC that delivers a 1A load current. The regulator has a preset switching frequency of either 550kHz (LM2734Y) or 1.6MHz (LM2734X). These high frequencies allow the LM2734 to operate with small surface mount capacitors and inductors, resulting in DC/DC converters that require a minimum amount of board space. The LM2734 is internally compensated, so it is simple to use, and requires few external components. The LM2734 uses current-mode control to regulate the output voltage.

The following operating description of the LM2734 will refer to the Simplified Block Diagram (Figure 22) and to the waveforms in Figure 23. The LM2734 supplies a regulated output voltage by switching the internal NMOS control switch at constant frequency and variable duty cycle. A switching cycle begins at the falling edge of the reset pulse generated by the internal oscillator. When this pulse goes low, the output control logic turns on the internal NMOS control switch. During this on-time, the SW pin voltage (VSW) swings up to approximately VIN, and the inductor current (IL) increases with a linear slope. ILis measured by the current-sense amplifier, which generates an output proportional to the switch current. The sense signal is summed with the regulator’s corrective ramp and compared to the error amplifier’s output, which is proportional to the difference between the feedback voltage and V next switching cycle begins. During the switch off-time, inductor current discharges through Schottky diode D1, which forces the SW pin to swing below ground by the forward voltage (VD) of the catch diode. The regulator loop adjusts the duty cycle (D) to maintain a constant output voltage.

. When the PWM comparator output goes high, the output switch turns off until the

REF

Figure 23. LM2734 Waveforms of SW Pin Voltage and Inductor Current

BOOST FUNCTION

Capacitor C drive voltage to the internal NMOS control switch. To properly drive the internal NMOS switch during its on-time, V

needs to be at least 1.6V greater than VSW. Although the LM2734 will operate with this minimum voltage,

BOOST

it may not have sufficient gate drive to supply large values of output current. Therefore, it is recommended that V

be greater than 2.5V above VSWfor best efficiency. V

BOOST

operating limit of 5.5V.

5.5V > V

BOOST

and diode D2 in Figure 24 are used to generate a voltage V

BOOST

– VSW> 2.5V for best performance.

BOOST

Product Folder Links: LM2734

BOOST

. V

- VSWis the gate

BOOST

– VSWshould not exceed the maximum

LM2734

BOOST

GND

OUT

BOOST

OUT

BOOST

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 24. V

Charges C

OUT

BOOST

When the LM2734 starts up, internal circuitry from the BOOST pin supplies a maximum of 20mA to C current charges C current to C

until the voltage at the feedback pin is greater than 0.76V.

BOOST

There are various methods to derive V

to a voltage sufficient to turn the switch on. The BOOST pin will continue to source

BOOST

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BOOST

. This

1. From the input voltage (VIN)

2. From the output voltage (V

3. From an external distributed voltage rail (V

OUT

)

EXT

4. From a shunt or series zener diode

In the Simplifed Block Diagram of Figure 22, capacitor C NMOS switch. Capacitor C internal NMOS control switch is off (T (V

), during which the current in the inductor (L) forward biases the Schottky diode D1 (V

FD2

voltage stored across C

- VSW= VIN- V

BOOST

FD2

is charged via diode D2 by VIN. During a normal switching cycle, when the

BOOST

) (refer to Figure 23), V

OFF

+ V

FD1

and diode D2 supply the gate-drive current for the

BOOST

equals VINminus the forward voltage of D2

BOOST

). Therefore the

FD1

(1)

When the NMOS switch turns on (TON), the switch pin rises to

VSW= VIN– (R

forcing V

BOOST

to rise thus reverse biasing D2. The voltage at V

BOOST

= 2VIN– (R

x IL), (2)

DSON

is then

BOOST

DSON

x IL) – V

FD2

+ V

FD1

(3)

which is approximately

2VIN- 0.4V (4)

for many applications. Thus the gate-drive voltage of the NMOS switch is approximately

VIN- 0.2V (5)

An alternate method for charging C

is to connect D2 to the output as shown in Figure 24. The output

BOOST

voltage should be between 2.5V and 5.5V, so that proper gate voltage will be applied to the internal switch. In this circuit, C

In applications where both VINand V directly from these voltages. If VINand V

provides a gate drive voltage that is slightly less than V

BOOST

are greater than 5.5V, or less than 3V, C

OUT

are greater than 5.5V, C

OUT

cannot be charged

can be charged from VINor V

BOOST

OUT

minus a zener voltage by placing a zener diode D3 in series with D2, as shown in Figure 25. When using a series zener diode from the input, ensure that the regulation of the input supply doesn’t create a voltage that falls outside the recommended V

(V (V

– VD3) < 5.5V

INMAX

– VD3) > 1.6V

INMIN

BOOST

voltage.

Product Folder Links: LM2734

LM2734

BOOST

GND

BOOST

OUT

LM2734

BOOST

GND

BOOST

OUT

BOOST

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Figure 25. Zener Reduces Boost Voltage from V

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

An alternative method is to place the zener diode D3 in a shunt configuration as shown in Figure 26. A small 350mW to 500mW 5.1V zener in a SOT or SOD package can be used for this purpose. A small ceramic capacitor such as a 6.3V, 0.1µF capacitor (C4) should be placed in parallel with the zener diode. When the internal NMOS switch turns on, a pulse of current is drawn to charge the internal NMOS gate capacitance. The

0.1 µF parallel shunt capacitor ensures that the V

voltage is maintained during this time.

BOOST

Resistor R3 should be chosen to provide enough RMS current to the zener diode (D3) and to the BOOST pin. A recommended choice for the zener current (I

) is 1 mA. The current I

ZENER

into the BOOST pin supplies the

BOOST

gate current of the NMOS control switch and varies typically according to the following formula for the X version:

= 0.56 x (D + 0.54) x (V

BOOST

can be calculated for the Y version using the following:

BOOST

= 0.22 x (D + 0.54) x (V

BOOST

where D is the duty cycle, V

ZENER

– VD2) mA (6)

ZENER

- VD2) µA (7)

ZENER

and VD2are in volts, and I

is in milliamps. V

BOOST

is the voltage applied to

ZENER

the anode of the boost diode (D2), and VD2is the average forward voltage across D2. Note that this formula for I

gives typical current. For the worst case I

BOOST

, increase the current by 40%. In that case, the worst case

BOOST

boost current will be

BOOST-MAX

= 1.4 x I

BOOST

(8)

R3 will then be given by

R3 = (VIN- V

For example, using the X-version let VIN= 10V, V

ZENER

) / (1.4 x I

BOOST

+ I

) (9)

ZENER

= 5V, VD2= 0.7V, I

ZENER

= 1mA, and duty cycle D = 50%.

ZENER

Then

= 0.56 x (0.5 + 0.54) x (5 - 0.7) mA = 2.5mA (10)

BOOST

R3 = (10V - 5V) / (1.4 x 2.5mA + 1mA) = 1.11kΩ (11)

Figure 26. Boost Voltage Supplied from the Shunt Zener on V

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D =

VO + V

VIN + VD - V

D =

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ENABLE PIN / SHUTDOWN MODE

The LM2734 has a shutdown mode that is controlled by the enable pin (EN). When a logic low voltage is applied to EN, the part is in shutdown mode and its quiescent current drops to typically 30nA. Switch leakage adds another 40nA from the input supply. The voltage at this pin should never exceed VIN+ 0.3V.

SOFT-START

This function forces V reference voltage ramps from 0V to its nominal value of 0.8V in approximately 200µs. This forces the regulator output to ramp up in a more linear and controlled fashion, which helps reduce inrush current. Under some circumstances at start-up, an output voltage overshoot may still be observed. This may be due to a large output load applied during start up. Large amounts of output external capacitance can also increase output voltage overshoot. A simple solution is to add a feed forward capacitor with a value between 470pf and 1000pf across the top feedback resistor (R1). See Figure 28 for further detail.

to increase at a controlled rate during start up. During soft-start, the error amplifier’s

OUT

OUTPUT OVERVOLTAGE PROTECTION

The overvoltage comparator compares the FB pin voltage to a voltage that is 10% higher than the internal reference Vref. Once the FB pin voltage goes 10% above the internal reference, the internal NMOS control switch is turned off, which allows the output voltage to decrease toward regulation.

UNDERVOLTAGE LOCKOUT

Undervoltage lockout (UVLO) prevents the LM2734 from operating until the input voltage exceeds 2.74V(typ). The UVLO threshold has approximately 440mV of hysteresis, so the part will operate until VINdrops below

2.3V(typ). Hysteresis prevents the part from turning off during power up if VINis non-monotonic.

CURRENT LIMIT

The LM2734 uses cycle-by-cycle current limiting to protect the output switch. During each switching cycle, a current limit comparator detects if the output switch current exceeds 1.7A (typ), and turns off the switch until the next switching cycle begins.

THERMAL SHUTDOWN

Thermal shutdown limits total power dissipation by turning off the output switch when the IC junction temperature exceeds 165°C. After thermal shutdown occurs, the output switch doesn’t turn on until the junction temperature drops to approximately 150°C.

Design Guide

INDUCTOR SELECTION

The Duty Cycle (D) can be approximated quickly using the ratio of output voltage (VO) to input voltage (VIN):

(12)

The catch diode (D1) forward voltage drop and the voltage drop across the internal NMOS must be included to calculate a more accurate duty cycle. Calculate D by using the following formula:

(13)

VSWcan be approximated by:

VSW= IOx R

DS(ON)

The diode forward drop (VD) can range from 0.3V to 0.7V depending on the quality of the diode. The lower VDis, the higher the operating efficiency of the converter.

(14)

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RMS-IN

= IO x

D x

1-D +

L =

VO + V

IO x r x f

x (1-D)

r =

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SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

The inductor value determines the output ripple current. Lower inductor values decrease the size of the inductor, but increase the output ripple current. An increase in the inductor value will decrease the output ripple current. The ratio of ripple current (ΔiL) to output current (IO) is optimized when it is set between 0.3 and 0.4 at 1A. The ratio r is defined as:

(15)

One must also ensure that the minimum current limit (1.2A) is not exceeded, so the peak current in the inductor must be calculated. The peak current (I

= IO+ ΔIL/2 (16)

LPK

) in the inductor is calculated by:

LPK

If r = 0.5 at an output of 1A, the peak current in the inductor will be 1.25A. The minimum specified current limit over all operating conditions is 1.2A. One can either reduce r to 0.4 resulting in a 1.2A peak current, or make the engineering judgement that 50mA over will be safe enough with a 1.7A typical current limit and 6 sigma limits. When the designed maximum output current is reduced, the ratio r can be increased. At a current of 0.1A, r can be made as high as 0.9. The ripple ratio can be increased at lighter loads because the net ripple is actually quite low, and if r remains constant the inductor value can be made quite large. An equation empirically developed for the maximum ripple ratio at any current below 2A is:

r = 0.387 x I

OUT

-0.3667

(17)

Note that this is just a guideline. The LM2734 operates at frequencies allowing the use of ceramic output capacitors without compromising

transient response. Ceramic capacitors allow higher inductor ripple without significantly increasing output ripple. See the output capacitor section for more details on calculating output voltage ripple.

Now that the ripple current or ripple ratio is determined, the inductance is calculated by:

(18)

where fsis the switching frequency and IOis the output current. When selecting an inductor, make sure that it is capable of supporting the peak output current without saturating. Inductor saturation will result in a sudden reduction in inductance and prevent the regulator from operating correctly. Because of the speed of the internal current limit, the peak current of the inductor need only be specified for the required maximum output current. For example, if the designed maximum output current is 0.5A and the peak current is 0.7A, then the inductor should be specified with a saturation current limit of >0.7A. There is no need to specify the saturation or peak current of the inductor at the 1.7A typical switch current limit. The difference in inductor size is a factor of 5. Because of the operating frequency of the LM2734, ferrite based inductors are preferred to minimize core losses. This presents little restriction since the variety of ferrite based inductors is huge. Lastly, inductors with lower series resistance (DCR) will provide better operating efficiency. For recommended inductors see Example Circuits.

INPUT CAPACITOR

An input capacitor is necessary to ensure that VINdoes not drop excessively during switching transients. The primary specifications of the input capacitor are capacitance, voltage, RMS current rating, and ESL (Equivalent Series Inductance). The recommended input capacitance is 10µF, although 4.7µF works well for input voltages below 6V. The input voltage rating is specifically stated by the capacitor manufacturer. Make sure to check any recommended deratings and also verify if there is any significant change in capacitance at the operating input voltage and the operating temperature. The input capacitor maximum RMS input current rating (I

RMS-IN

) must be

greater than:

(19)

It can be shown from the above equation that maximum RMS capacitor current occurs when D = 0.5. Always calculate the RMS at the point where the duty cycle, D, is closest to 0.5. The ESL of an input capacitor is usually determined by the effective cross sectional area of the current path. A large leaded capacitor will have high ESL and a 0805 ceramic chip capacitor will have very low ESL. At the operating frequencies of the LM2734, certain capacitors may have an ESL so large that the resulting impedance (2πfL) will be higher than that required to

Product Folder Links: LM2734

R1 =

- 1

REF

x R2

RMS-OUT

= IO x

'VO = 'iL x (R

ESR

8 x fS x C

)

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SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

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provide stable operation. As a result, surface mount capacitors are strongly recommended. Sanyo POSCAP, Tantalum or Niobium, Panasonic SP or Cornell Dubilier ESR, and multilayer ceramic capacitors (MLCC) are all good choices for both input and output capacitors and have very low ESL. For MLCCs it is recommended to use X7R or X5R dielectrics. Consult capacitor manufacturer datasheet to see how rated capacitance varies over operating conditions.

OUTPUT CAPACITOR

The output capacitor is selected based upon the desired output ripple and transient response. The initial current of a load transient is provided mainly by the output capacitor. The output ripple of the converter is:

(20)

When using MLCCs, the ESR is typically so low that the capacitive ripple may dominate. When this occurs, the output ripple will be approximately sinusoidal and 90° phase shifted from the switching action. Given the availability and quality of MLCCs and the expected output voltage of designs using the LM2734, there is really no need to review any other capacitor technologies. Another benefit of ceramic capacitors is their ability to bypass high frequency noise. A certain amount of switching edge noise will couple through parasitic capacitances in the inductor to the output. A ceramic capacitor will bypass this noise while a tantalum will not. Since the output capacitor is one of the two external components that control the stability of the regulator control loop, most applications will require a minimum at 10 µF of output capacitance. Capacitance can be increased significantly with little detriment to the regulator stability. Like the input capacitor, recommended multilayer ceramic capacitors are X7R or X5R. Again, verify actual capacitance at the desired operating voltage and temperature.

Check the RMS current rating of the capacitor. The RMS current rating of the capacitor chosen must also meet the following condition:

(21)

CATCH DIODE

The catch diode (D1) conducts during the switch off-time. A Schottky diode is recommended for its fast switching times and low forward voltage drop. The catch diode should be chosen so that its current rating is greater than:

ID1= IOx (1-D) (22)

The reverse breakdown rating of the diode must be at least the maximum input voltage plus appropriate margin. To improve efficiency choose a Schottky diode with a low forward voltage drop.

BOOST DIODE

A standard diode such as the 1N4148 type is recommended. For V

circuits derived from voltages less than

BOOST

3.3V, a small-signal Schottky diode is recommended for greater efficiency. A good choice is the BAT54 small signal diode.

BOOST CAPACITOR

A ceramic 0.01µF capacitor with a voltage rating of at least 6.3V is sufficient. The X7R and X5R MLCCs provide the best performance.

OUTPUT VOLTAGE

The output voltage is set using the following equation where R2 is connected between the FB pin and GND, and R1 is connected between VOand the FB pin. A good value for R2 is 10kΩ.

(23)

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

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PCB Layout Considerations

When planning layout there are a few things to consider when trying to achieve a clean, regulated output. The most important consideration when completing the layout is the close coupling of the GND connections of the C capacitor and the catch diode D1. These ground ends should be close to one another and be connected to the GND plane with at least two through-holes. Place these components as close to the IC as possible. Next in importance is the location of the GND connection of the C

capacitor, which should be near the GND

OUT

connections of CINand D1. There should be a continuous ground plane on the bottom layer of a two-layer board except under the switching

node island. The FB pin is a high impedance node and care should be taken to make the FB trace short to avoid noise pickup

and inaccurate regulation. The feedback resistors should be placed as close as possible to the IC, with the GND of R2 placed as close as possible to the GND of the IC. The V

trace to R1 should be routed away from the

OUT

inductor and any other traces that are switching. High AC currents flow through the VIN, SW and V

traces, so they should be as short and wide as possible.

OUT

However, making the traces wide increases radiated noise, so the designer must make this trade-off. Radiated noise can be decreased by choosing a shielded inductor.

The remaining components should also be placed as close as possible to the IC. Please see Application Note AN-1229 SNVA054 for further considerations and the LM2734 demo board as an example of a four-layer layout.

LM2734X Circuit Examples

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734X Texas Instruments C1, Input Cap 10µF, 6.3V, X5R C3216X5ROJ106M TDK C2, Output Cap 10µF, 6.3V, X5R C3216X5ROJ106M TDK C3, Boost Cap 0.01uF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.3VFSchottky 1A, 10VR MBRM110L ON Semi D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. L1 4.7µH, 1.7A, VLCF4020T- 4R7N1R2 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay

R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

Figure 27. LM2734X (1.6MHz)

Derived from V

BOOST

5V to 1.5V/1A

Table 1. Bill of Materials for Figure 27

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

12V

3.3V

OFF

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 28. LM2734X (1.6MHz)

Derived from V

BOOST

OUT

12V to 3.3V/1A

Table 2. Bill of Materials for Figure 28

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator NSC LM2734X C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK CFF 1000pF 25V C0603X5R1E102K TDK D1, Catch Diode 0.34VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. L1 4.7µH, 1.7A VLCF4020T- 4R7N1R2 TDK R1 31.6kΩ, 1% CRCW06033162F Vishay R2 10kΩ, 1% CRCW06031002F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

www.ti.com

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

www.ti.com

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 29. LM2734X (1.6MHz)

Derived from V

BOOST

SHUNT

18V to 1.5V/1A

Table 3. Bill of Materials for Figure 29

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734X Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK C4, Shunt Cap 0.1µF, 6.3V, X5R C1005X5R0J104K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 5.1V 250Mw SOT BZX84C5V1 Vishay L1 6.8µH, 1.6A, SLF7032T-6R8M1R6 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay R4 4.12kΩ, 1% CRCW06034121F Vishay

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

D2D3

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 30. LM2734X (1.6MHz)

Derived from Series Zener Diode (VIN)

BOOST

15V to 1.5V/1A

Table 4. Bill of Materials for Figure 30

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734X Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 11V 350Mw SOT BZX84C11T Diodes, Inc. L1 6.8µH, 1.6A, SLF7032T-6R8M1R6 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

www.ti.com

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

www.ti.com

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 31. LM2734X (1.6MHz)

Derived from Series Zener Diode (V

BOOST

OUT

)

15V to 9V/1A

Table 5. Bill of Materials for Figure 31

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734X Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 16V, X5R C3216X5R1C226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 4.3V 350mw SOT BZX84C4V3 Diodes, Inc. L1 6.8µH, 1.6A, SLF7032T-6R8M1R6 TDK R1 102kΩ, 1% CRCW06031023F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

LM2734Y Circuit Examples

Figure 32. LM2734Y (550kHz)

Table 6. Bill of Materials for Figure 32

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734Y Texas Instruments C1, Input Cap 10µF, 6.3V, X5R C3216X5ROJ106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.3VFSchottky 1A, 10VR MBRM110L ON Semi D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. L1 10µH, 1.6A, SLF7032T-100M1R4 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

Derived from V

BOOST

5V to 1.5V/1A

www.ti.com

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

12V

3.3V

OFF

LM2734

www.ti.com

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 33. LM2734Y (550kHz)

Derived from V

BOOST

OUT

12V to 3.3V/1A

Table 7. Bill of Materials for Figure 33

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734Y Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.34VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 0.6VF@ 30mA Diode BAT17 Vishay L1 10µH, 1.6A, SLF7032T-100M1R4 TDK R1 31.6kΩ, 1% CRCW06033162F Vishay R2 10.0 kΩ, 1% CRCW06031002F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 34. LM2734Y (550kHz)

Derived from V

BOOST

SHUNT

18V to 1.5V/1A

Table 8. Bill of Materials for Figure 34

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734Y Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK C4, Shunt Cap 0.1µF, 6.3V, X5R C1005X5R0J104K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 5.1V 250Mw SOT BZX84C5V1 Vishay L1 15µH, 1.5A SLF7045T-150M1R5 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay R4 4.12kΩ, 1% CRCW06034121F Vishay

www.ti.com

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

D2D3

LM2734

www.ti.com

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 35. LM2734Y (550kHz)

Derived from Series Zener Diode (VIN)

BOOST

15V to 1.5V/1A

Table 9. Bill of Materials for Figure 35

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734Y Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 6.3V, X5R C3216X5ROJ226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 11V 350Mw SOT BZX84C11T Diodes, Inc. L1 15µH, 1.5A, SLF7045T-150M1R5 TDK R1 8.87kΩ, 1% CRCW06038871F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

Product Folder Links: LM2734

LM2734

VIN

BOOST

GND

OUT

OFF

LM2734

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

Figure 36. LM2734Y (550kHz)

Derived from Series Zener Diode (V

BOOST

OUT

)

15V to 9V/1A

Table 10. Bill of Materials for Figure 36

Part ID Part Value Part Number Manufacturer

U1 1A Buck Regulator LM2734Y Texas Instruments C1, Input Cap 10µF, 25V, X7R C3225X7R1E106M TDK C2, Output Cap 22µF, 16V, X5R C3216X5R1C226M TDK C3, Boost Cap 0.01µF, 16V, X7R C1005X7R1C103K TDK D1, Catch Diode 0.4VFSchottky 1A, 30VR SS1P3L Vishay D2, Boost Diode 1VF@ 50mA Diode 1N4148W Diodes, Inc. D3, Zener Diode 4.3V 350mw SOT BZX84C4V3 Diodes, Inc. L1 22µH, 1.4A, SLF7045T-220M1R3-1PF TDK R1 102kΩ, 1% CRCW06031023F Vishay R2 10.2kΩ, 1% CRCW06031022F Vishay R3 100kΩ, 1% CRCW06031003F Vishay

www.ti.com

Product Folder Links: LM2734

LM2734

www.ti.com

SNVS288I –SEPTEMBER 2004–REVISED APRIIL 2013

REVISION HISTORY

Changes from Revision H (April 2013) to Revision I Page

• Changed layout of National Data Sheet to TI format .......................................................................................................... 24

Product Folder Links: LM2734

PACKAGE OPTION ADDENDUM

www.ti.com

1-Nov-2013

Addendum-Page 1

PACKAGING INFORMATION

Orderable Device Status

(1)

Package Type Package

Drawing

Pins Package

Qty

Eco Plan

(2)

Lead/Ball Finish

(6)

MSL Peak Temp

(3)

Op Temp (°C) Device Marking

(4/5)

Samples

LM2734XMK/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SFDB

LM2734XMKX/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SFDB

LM2734XQMK/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SUKB

LM2734XQMKE/NOPB ACTIVE SOT DDC 6 250 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SUKB

LM2734XQMKX/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SUKB

LM2734YMK NRND SOT DDC 6 1000 TBD Call TI Call TI -40 to 125 SFEB

LM2734YMK/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SFEB

LM2734YMKX NRND SOT DDC 6 3000 TBD Call TI Call TI -40 to 125 SFEB

LM2734YMKX/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SFEB

LM2734YQMK/NOPB ACTIVE SOT DDC 6 1000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SVCB

LM2734YQMKE/NOPB ACTIVE SOT DDC 6 250 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SVCB

LM2734YQMKX/NOPB ACTIVE SOT DDC 6 3000 Green (RoHS

& no Sb/Br)

CU SN Level-1-260C-UNLIM -40 to 125 SVCB

(1)

The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability

information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that

lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

PACKAGE OPTION ADDENDUM

www.ti.com

1-Nov-2013

Addendum-Page 2

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(3)

MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

(4)

There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device.

(5)

Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation

of the previous line and the two combined represent the entire Device Marking for that device.

(6)

Lead/Ball Finish - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead/Ball Finish values may wrap to two lines if the finish

value exceeds the maximum column width.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

OTHER QUALIFIED VERSIONS OF LM2734, LM2734-Q1 :

•

Catalog: LM2734

•

Automotive: LM2734-Q1

NOTE: Qualified Version Definitions:

•

Catalog - TI's standard catalog product

•

Automotive - Q100 devices qualified for high-reliability automotive applications targeting zero defects

PACKAGE MATERIALS INFORMATION

www.ti.com 8-Apr-2013

TAPE AND REEL INFORMATION

*All dimensions are nominal

Device Package

Type

LM2734XMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734XMKX/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734XQMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2734XQMKE/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2734XQMKX/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734YMK SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734YMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734YMKX SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734YMKX/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

LM2734YQMK/NOPB SOT DDC 6 1000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2734YQMKE/NOPB SOT DDC 6 250 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3 LM2734YQMKX/NOPB SOT DDC 6 3000 178.0 8.4 3.2 3.2 1.4 4.0 8.0 Q3

Package Drawing

Pins SPQ Reel

Diameter

(mm)

Reel

Width

W1 (mm)

(mm)B0(mm)K0(mm)P1(mm)W(mm)

Pin1

Quadrant

Pack Materials-Page 1

PACKAGE MATERIALS INFORMATION

www.ti.com 8-Apr-2013

*All dimensions are nominal

Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)

LM2734XMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0

LM2734XMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.0

LM2734XQMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LM2734XQMKE/NOPB SOT DDC 6 250 210.0 185.0 35.0 LM2734XQMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.0

LM2734YMK SOT DDC 6 1000 210.0 185.0 35.0

LM2734YMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0

LM2734YMKX SOT DDC 6 3000 210.0 185.0 35.0

LM2734YMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.0

LM2734YQMK/NOPB SOT DDC 6 1000 210.0 185.0 35.0 LM2734YQMKE/NOPB SOT DDC 6 250 210.0 185.0 35.0 LM2734YQMKX/NOPB SOT DDC 6 3000 210.0 185.0 35.0

Pack Materials-Page 2

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Texas Instruments LM2734 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual