Selection of external components

AN3223

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Doc ID 17553 Rev 2

This status is latched, until the microcontroller reads the STATUS register. Reading the

STATUS register clears the NTC_H bit.

The selection of the NTC and RX resistor values strongly depends on the power dissipated

by the LED and all components surrounding the NTC-thermistor and on the cooling

capabilities of each specific application. The RX and the NTC values in

Table 1 below work

well in the demonstration board presented in this application note. A real application may

require a different type of NTC-thermistor to achieve optimal thermal protection.

The procedure to activate the NTC-feature is described in

Section 5.2: Monitoring mode.

Table 1.

Recommended components

Component

Manufacturer

Part number

Value

Size

L

Murata

LQM2HPN1R0MJC

1 µH / 1.5 A

2.5 x 2.0 x 1.1 mm

TDK

VLS252012T-1R0N1R7

1 µH / 1.7 A

2.5 x 2.0 x 1.2 mm

CIN,COUT

TDK

C1608X5R0J106MT

10 µF / 6.3 V

0603

Rx

Rohm

MCR01MZPJ15K

15 k

Ω

0402

NTC

Murata

NCP21WF104J03RA

100 k

Ω

0805

CSUP

Murata

DME2W5R5K404M

400 mF / 5.5 V

20.5 x 18.5 x 3 mm

TDK

EDLC152344

550 mF / 5.5 V

44 x 23 x 1.5 mm

EDLC272020

500 mF / 5.5 V

20 x 20 x 2.7 mm

CAP-xx

GS 2 19F

1.6 F / 5 V

40 x 17 mm

LED MODUL

Luxeon

4x LXCL-PWF4

White LED

0805

STMicroelectronics

STL8NH3LL

8 A / 12 m

Ω

3.3 x 3.3 x 0.9 mm

Tyco

TL2BR01FTE

0R01

1206

(1)

TDK

10 µF / 6.3 V

0402

(1)

Tyco

0402

(1)

Vishay

TEMT6000

4 x 2 x 1 mm

AUXLED

Red LED

0603

100 nF

0402

1.

Optional components for the auxiliary light sensor feature.