LP38511MR-ADJEV/NOPB National Semiconductor, LP38511MR-ADJEV/NOPB Datasheet

LP38511MR-ADJEV/NOPB

Manufacturer Part Number

LP38511MR-ADJEV/NOPB

Description

BOARD EVALUATION FOR LP38511

Manufacturer

National Semiconductor

Datasheets

1.LP38511MR-ADJEVNOPB.pdf (14 pages)

2.LP38511MR-ADJEVNOPB.pdf (8 pages)

Specifications of LP38511MR-ADJEV/NOPB

Channels Per Ic

1 - Single

Voltage - Output

1.2V

Current - Output

800mA

Voltage - Input

2.25 ~ 5.5V

Regulator Type

Positive Adjustable

Operating Temperature

-40°C ~ 125°C

Board Type

Fully Populated

Utilized Ic / Part

LP38511

Silicon Manufacturer

National

Silicon Core Number

LP38511MR-ADJ

Kit Application Type

Power Management - Voltage Regulator

Application Sub Type

LDO

Kit Contents

Board, Doc

Lead Free Status / RoHS Status

Contains lead / RoHS non-compliant

Other names

LP38511MR-ADJEV

Current page: 1 of 8
Download datasheet (499Kb)

LP38511MR-ADJ Evaluation

Board

Introduction

This board is designed to allow the evaluation of the

LP38511MR-ADJ Voltage Regulator. Each board is assem-

bled and tested in the factory. This evaluation board has the

PSOP-8 package mounted, and the output voltage is set to

1.20V.

General Description

The LP38511MR-ADJ is an adjustable LDO linear regulator

capable of supplying up to 800 mA of output current, and in-

corporates an Enable function.

The device has been designed to work with 10 µF input and

output ceramic capacitors. Footprints areas for C

Operation

The input voltage, applied between V

at least 2.25V, or at least 500 mV greater than V

er value is larger. The input voltage should be no greater than

5.5V, which is the high end of the Operating Rating voltage.

Loads can be connected to V

accurate measurements directly onto the input and output

pins of the device, eliminating any voltage drop on the PCB

traces or connecting wires to the load.

Setting V

The output voltage is set using the external resistive divider

R1 and R2. The output voltage is given by the formula:

It is recommended that the values selected for R1 and R2 are

such that the parallel value is less than 1.00 kΩ. This is to

prevent internal parasitic capacitances on the ADJ pin from

interfering with the F

Table 1 lists some suggested, best fit, standard ±1% resistor

values for R1 and R2, and a standard ±10% capacitor values

for C

and C

OUT

will allow for a variety of sizes.

and V

, for a range of V

are available that will give similar results.

( (R1 x R2) / (R1 + R2) )

test points are provided on the board to allow

OUT

= V

ADJ

pole set by R1 and C

OUT

x (1 + (R1 / R2))

values. Other values of R1, R2,

OUT

with reference to GND.

≤

and GND, should be

1.00 kΩ

300478

OUT

, whichev-

and

(1)

National Semiconductor

Application Note 1770

Don Jones

April 10, 2009

Refer to Application Note AN-1378 for additional information

on how resistor tolerances affect the calculated V

The LP38511MR-ADJ Evaluation board is assembled with a

1.40 kΩ ±1% resistor for R1, and a 1.00 kΩ ±1% resistor for

R2. This sets V

Selecting C

A capacitor placed across the gain resistor R1 will provide

additional phase margin to improve load transient response

of the device. This capacitor, C

a zero in the loop response given by the formula:

The value for C

The closest standard 10% value is usually adequate for C

The LP38511MR-ADJ Evaluation board is assembled with a

3300 pF capacitor for C

kHz.

0.80V

1.00V

1.20V

1.50V

1.80V

2.00V

2.50V

3.00V

3.30V

) between 25 kHz and 50 kHz using the formula:

OUT

= (1 / (2 x

OUT

= 500 mV x (1 + (1.40 kΩ / 1.00 kΩ ) )

1.07 kΩ

1.00 kΩ

1.40 kΩ

2.00 kΩ

2.94 kΩ

1.02 kΩ

1.00 kΩ

2.00 kΩ

OUT

= (1 / (2 x

should be selected to set a zero frequency

x 3300 pF x 1.40kΩ ) ) = 34.4 kHz

= 1 / (2 x

to 1.20V.

1.78 kΩ

1.00 kΩ

1.13 kΩ

TABLE 1.

340Ω

255Ω

200Ω

357Ω

. This sets F

x C

x F

, in parallel with R1, will form

x R1) )

x R1)

4700 pF

3300 pF

2700 pF

1500 pF

4700 pF

2700 pF

to approximately 34

www.national.com

31.6 kHz

33.8 kHz

34.4 kHz

29.5 kHz

36.1 kHz

33.2 kHz

33.8 kHz

29.5 kHz

OUT

value.

(2)

(3)

(4)

(5)

Related parts for LP38511MR-ADJEV/NOPB

LP38511MR-ADJEV/NOPB Summary of contents

Page 1

... This capacitor zero in the loop response given by the formula: (1) The value for between 25 kHz and 50 kHz using the formula ≤ The closest standard 10% value is usually adequate for C 1.00 kΩ The LP38511MR-ADJ Evaluation board is assembled with a 3300 pF capacitor for C kHz 300478 TABLE 4700 pF 1.07 kΩ ...

Page 2

... EN hysteresis. www.national.com 30047807 In applications where the LP38511MR-ADJ is operated con- tinuously the Enable pin can be connected directly to V Enable pin has no default bias and must not be left floating. The Enable pin must be actively driven to the appropriate voltage level. ...

Page 3

FIGURE 5. Maximum Power Dissipation vs Ambient Temperature 30047806 3 www.national.com ...

Page 4

Connection Diagram Schematic Diagram PCB Layout www.national.com 30047803 Evaluation Board Schematic. Evaluation Board Component and Pin Layout 4 30047801 30047802 ...

Page 5

Top Side Copper Area 30047811 Bottom Side Copper Area 5 www.national.com ...

Page 6

... Johnson Components Terminal; Black Terminal; Orange 125 mW; ±100 ppm; 0805 125 mW; ±100 ppm; 0805 125 mW; ±100 ppm; 0805 Diameter = 0.062” 6 Manufacturer Part Number 600173 Corporation LP38511MR-ADJ NOPB Corporation 1210ZC106KAT2A AVX 1210ZC106KAT2A KEMET C0805C332K5RAC 108-0901-001 108-0902-001 108-0903-001 108-0906-001 CRCW08051K40FK VISHAY DALE ...

Page 7

Notes 7 www.national.com ...

Page 8

... For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Amplifiers www.national.com/amplifiers Audio www.national.com/audio Clock and Timing www.national.com/timing Data Converters www.national.com/adc Interface www.national.com/interface LVDS www.national.com/lvds Power Management www.national.com/power Switching Regulators www.national.com/switchers LDOs www.national.com/ldo LED Lighting www ...

Related keywords

lp38502
lp38512
lp38511
lp38501
lp3852
lp38513
lp38512mr
LP38511MR-ADJEV/NOPB datasheet
LP38511MR-ADJEV/NOPB data sheet
LP38511MR-ADJEV/NOPB pdf datasheet
LP38511MR-ADJEV/NOPB component
LP38511MR-ADJEV/NOPB part
LP38511MR-ADJEV/NOPB distributor
LP38511MR-ADJEV/NOPB RoHS
LP38511MR-ADJEV/NOPB datasheet download