evalua tion board da ta sheet ev176 - …. ev176. evalua tion board da ta sheet. evaluation board...

1

EV176EVALUATION BOARD DATA SHEET

Evaluation Board for the AAT1409/7/5 Eight/Six/Four-Channel LED Backlight Driverwith Integrated Boost and High Frequency Direct PWM Dimming

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202317A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • August 30, 2012

Introduction The AAT1409/07/05 evaluation board provides a platform for evaluating the family of 8-channel / 6-channel / 4-chan-nel LED backlight drivers. The PCB layout has been optimized for portable device applications with a minimum number of external components in a small area. The design operates across an input voltage range of 4.5V to 5.5V (if VIN = VCC) or 5.0V to 26V (if VIN is connected only with VCC open).

Schematics

R3442k

R412.1k

MSS1P6

D1VIN5V - 26V

C42.2µF50V0805

R27.5k

R14.99k

C110µF35V

C22.2µF10V C3

15nF

JP4

JP2

VOUT

PWM5

CS2 7

GN

D

CS1 6

CS3 8

CS4 9

SG

ND

CS5 11RSET15

COMP16

OVP 17

GN

D

GN

D

FSET2

SYNC1CS6 12

CS7 13

CS8 14

LX

19

PG

ND

GN

DIN24EN23

VCC22

AAT1409

U1TQFN34-24

10 LEDs in series

4310 18 21 20E

P

L1 Sumida, CDRH5D28RHPNP-4R7N, 4.7μH, 3.7A, DCR = 43.1mΩD1 Vishay, Schottky Barrier Diode, MSS1P6, 1A, 60VC1 Taiyo Yuden, GMK325BJ106KN-T, 10μF, 35V, X5R,1210; OR Murata GRM32ER71H106K, 10μF, 50V, X7R, 1210C2 2.2μF, 10V, 0603C3 Cap, 15nF, 10V, 0603C4 Murata, GRM31CR71H225KA88L, 2.2μF, 50V, X7R, 1206R1, R2, R3, R4 Carbon Film resistors, 1%, 0603

L1 4.7μH

JP1

JP3

Figure 1: AAT1409 Evaluation Board Schematic.

DISCON

TINU

ED

2




R3442k

R412.1k

MSS1P6

D1VIN5V - 26V

C42.2µF50V0805

R27.5k

R14.99k

C110µF35V

C22.2µF10V C3

15nF

JP5

JP2

VOUT

PWM5

CS2 7

GN

D

CS1 6

CS3 8

CS4 9

SG

ND

CS5 11RSET15

COMP16

OVP 17

GN

D

GN

D

FSET2

SYNC1CS6 12

GND 13

GND 14

LX

19

PG

ND

GN

D

IN24EN23

VCC22

AAT1407

U1TQFN34-24

10 LEDs in series

4310 18 21 20E

P

L1 Sumida, CDRH5D28RHPNP-4R7N, 4.7μH, 3.7A, DCR = 43.1mΩD1 Vishay, Schottky Barrier Diode, MSS1P6, 1A, 60VC1 Taiyo Yuden, GMK325BJ106KN-T, 10μF, 35V, X5R,1210; OR Murata GRM32ER71H106K, 10μF, 50V, X7R, 1210C2 2.2μF, 10V, 0603C3 Cap, 15nF, 10V, 0603C4 Murata, GRM31CR71H225KA88L, 2.2μF, 50V, X7R, 1206R1, R2, R3, R4 Carbon Film resistors, 1%, 0603

L1 4.7μH

JP1

JP3


DISCON

TINU

ED

3




R3442k

R412.1k

MSS1P6

D1VIN5V - 26V

C42.2µF50V0805

R27.5k

R14.99k

C110µF35V

C22.2µF10V C3

15nF

JP5

JP2

VOUT

PWM5

CS2

9

GN

D

CS1

8

CS3

6

CS4

7

SG

ND

GNDGNDGNDGND

11

RSET15

COMP16

OVP 17

GN

D

GN

D

FSET2

SYNC1

12

1314

LX

19

PG

ND

GN

D

IN24EN23

VCC22

AAT1405

U1TQFN34-24

4 LEDs in series

4310 18 21 20E

P

L1 Sumida, CDRH5D28RHPNP-4R7N, 4.7μH, 3.7A, DCR = 43.1mΩD1 Vishay, Schottky Barrier Diode, MSS1P6, 1A, 60VC1 Taiyo Yuden, GMK325BJ106KN-T, 10μF, 35V, X5R,1210; OR Murata GRM32ER71H106K, 10μF, 50V, X7R, 1210C2 2.2μF, 10V, 0603C3 15nF, 10V, 0603C4 Murata, GRM31CR71H225KA88L, 2.2μF, 50V, X7R, 1206R1, R2, R3, R4 Carbon Film resistors, 1%, 0603

L1 4.7μH

JP1

JP3


DISCON

TINU

ED

4




Test Equipment1. Unit under test (UUT) is the AAT1409/07/05 Evaluation Board.2. One (1) XT30-2 Power Supplies or equivalent.3. One PWM Function Generator. 4. One Fluke 189 multi-meter or equivalent to measure the output voltage.5. Miscellaneous test leads (banana plug to clip lead type is recommended).

Setup and Test

Quick Setup Guide1. Configure and verify the evaluation board as shown in Figure 4 prior to applying any power.2. Verify the jumper JP1 at ON position; disable the synchronization function using jumper JP2; set the switching

frequency either at 675kHz (Lo) or 1.3MHz (Hi) using JP3.3. Connect a function generator to JP4 with the PWM amplitude from 0V to 5V, the PWM frequency range from 100Hz

to 100 kHz, and the PWM duty cycle range from 1% to 99%. 4. Connect a 12V power supply to the input voltage (VIN), and connect an appropriate WLED board to the “to LED

Panel” terminal on the board. 5. Turn on the Power Supply; the LED panel should be turn ON.6. Vary the PWM frequency while monitoring the LED dimming, and vary the dimming of the LED panel by adjusting

the PWM duty cycle.

DISCON

TINU

ED

5




Setting Over-Voltage Protection (OVP) The resistor divider must be selected so that the voltage at the OVP pin exceeds the OVP rising threshold at VOUT(MAX)

and the maximum LX voltage does not exceed its maximum value (50V). Therefore, the value of R3 should be chosen within the range of the following equation:

R4 · < R3 < R4 · - 1VCSX + N · VFLED(MAX) - VOVP(MIN)

VOVP(MIN)

50VVOVP(MAX)

Where:

R4 = 12.1kΩ is selected for minimizing losses without degrading noise immunity.N is the number of LEDs in each string.VOVP(MIN) = 1.1V is minimum over-voltage threshold.VOVP(MAX) = 1.3V is maximum over-voltage threshold.VCSX = 0.5V is the current sink voltage.VFLED(MAX) is the maximum forward LED voltage at 20mA.

For example, if the number of the white LED in each string is N =11, the resistor divider R3 can be calculated by select-ing R4 = 12.1kΩ:

12.1kΩ · < R3 < 12.1kΩ · - 10.5V + 11 · 3.7V - 1.1

1.150V1.3V

441.1kΩ < R3 < 453.3kΩ; choose R3 = 442kΩ (closest 1% value)

Check the maximum output voltage with the selected values of R4, R3:

VOUT(MAX) = VOVP(MAX) · = 1.3V · = 48.8V < 50V+ 1R3

R4+ 1

442kΩ12.1kΩ

DISCON

TINU

ED

6




1. AAT1409 only.

LED Current Sink SettingThe current sink is set by the R2 resistor:

R2 = 264 · VRSET

ICSX(MAX) =

264 · 0.6VICSX(MAX)

Where VRSET = 0.6V

For example, if the maximum current for each string LEDs is 30mA, this corresponds to a minimum resistor of 5.23kΩ.

R2 = = 5.23kΩ264 · 0.6V

30mA

Maximum ILED Current (mA) R2 (kΩ)451 3.4830 5.2325 6.1920 7.8715 10.510 15.85 31.6

Table 1. Maximum LED Current Sink vs. RSET Resistor (R2) Values.

DISCON

TINU

ED

7




Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved.

Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. These materials, including the information contained herein, are provided by Skyworks as a service to its customers and may be used for informational purposes only by the customer. Skyworks assumes no responsibility for errors or omissions in these materials or the information contained herein. Sky-works may change its documentation, products, services, specifications or product descriptions at any time, without notice. Skyworks makes no commitment to update the materials or information and shall have no responsibility whatsoever for conflicts, incompatibilities, or other difficulties arising from any future changes.

No license, whether express, implied, by estoppel or otherwise, is granted to any intellectual property rights by this document. Skyworks assumes no liability for any materials, products or information provided here-under, including the sale, distribution, reproduction or use of Skyworks products, information or materials, except as may be provided in Skyworks Terms and Conditions of Sale.

THE MATERIALS, PRODUCTS AND INFORMATION ARE PROVIDED “AS IS” WITHOUT WARRANTY OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, INCLUDING FITNESS FOR A PARTICULAR PURPOSE OR USE, MERCHANTABILITY, PERFORMANCE, QUALITY OR NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHT; ALL SUCH WARRANTIES ARE HEREBY EXPRESSLY DISCLAIMED. SKYWORKS DOES NOT WARRANT THE ACCURACY OR COMPLETENESS OF THE INFORMATION, TEXT, GRAPHICS OR OTHER ITEMS CONTAINED WITHIN THESE MATERIALS. SKYWORKS SHALL NOT BE LIABLE FOR ANY DAMAGES, IN-CLUDING BUT NOT LIMITED TO ANY SPECIAL, INDIRECT, INCIDENTAL, STATUTORY, OR CONSEQUENTIAL DAMAGES, INCLUDING WITHOUT LIMITATION, LOST REVENUES OR LOST PROFITS THAT MAY RESULT FROM THE USE OF THE MATERIALS OR INFORMATION, WHETHER OR NOT THE RECIPIENT OF MATERIALS HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Skyworks products are not intended for use in medical, lifesaving or life-sustaining applications, or other equipment in which the failure of the Skyworks products could lead to personal injury, death, physical or en-vironmental damage. Skyworks customers using or selling Skyworks products for use in such applications do so at their own risk and agree to fully indemnify Skyworks for any damages resulting from such improper use or sale.

Customers are responsible for their products and applications using Skyworks products, which may deviate from published specifications as a result of design defects, errors, or operation of products outside of pub-lished parameters or design specifications. Customers should include design and operating safeguards to minimize these and other risks. Skyworks assumes no liability for applications assistance, customer product design, or damage to any equipment resulting from the use of Skyworks products outside of stated published specifications or parameters.

Skyworks, the Skyworks symbol, and “Breakthrough Simplicity” are trademarks or registered trademarks of Skyworks Solutions, Inc., in the United States and other countries. Third-party brands and names are for identification purposes only, and are the property of their respective owners. Additional information, including relevant terms and conditions, posted at www.skyworksinc.com, are incorporated by reference.

1. Applied the same for both AAT1407 and AAT1405 evaluation boards.

Figure 4: AAT1409 Evaluation Board Quick Setup Guide Connection Diagram1.

DISCON

TINU

ED

evalua tion board da ta sheet ev176 - …. ev176. evalua tion board da ta sheet. evaluation board...

Documents