LT3465/LT3465A

8

3465afa

skipping using a 1k resistor from FB to GND. The photo

in Figure 3b details circuit operation driving three white

LEDs at a 0.2mA load. Peak inductor current is less

than 30mA.

Inductor Selection

A 22

µH inductor is recommended for most LT3465 appli-

cations. Although small size and high efficiency are major

concerns, the inductor should have low core losses at

1.2MHz and low DCR (copper wire resistance). Some

inductors in this category with small size are listed in

Table 1. The efficiency comparison of different inductors

is shown in Figure 4a. A 22

µH or 10µH inductor is recom-

mended for most LT3465A applications. The inductor

should have low core losses at 2.4MHz and low DCR. The

efficiency comparison of different inductors is shown in

figure 4b.

Table 1. Recommended Inductors

PART

CURRENT RATING

NUMBER

DCR (

Ω)

(mA)

MANUFACTURER

LQH32CN220

0.71

250

Murata

LQH2MCN220

2.4

185

814-237-1431

www.murata.com

ELJPC220KF

4.0

160

Panasonic

714-373-7334

www.panasonic.com

CDRH3D16-220

0.53

350

Sumida

847-956-0666

www.sumida.com

LB2012B220M

1.7

75

Taiyo Yuden

408-573-4150

www.t-yuden.com

LEM2520-220

5.5

125

Taiyo Yuden

408-573-4150

www.t-yuden.com

LED CURRENT (mA)

0

70

75

15

3465A F04b

65

60

510

20

55

50

80

4 LEDs

MURATA LQH32CN220

MURATA LQH32CN100

MURATA LQH2MCN220

TOKO D312-220

TOKO D312-100

TAIYO YUDEN LB2012B220

APPLICATIO S I FOR ATIO

Capacitor Selection

The small size of ceramic capacitors makes them ideal for

LT3465 and LT3465A applications. X5R and X7R types are

recommended because they retain their capacitance over

wider voltage and temperature ranges than other types

such as Y5V or Z5U. A 1

µF input capacitor and a 0.22µF

output capacitor are sufficient for most LT3465 and

LT3465A applications.

Table 2. Recommended Ceramic Capacitor Manufacturers

MANUFACTURER

PHONE

URL

Taiyo Yuden

408-573-4150

www.t-yuden.com

Murata

814-237-1431

www.murata.com

Kemet

408-986-0424

www.kemet.com

LED CURRENT (mA)

0

70

75

85

15

3465A F04b

65

60

510

20

55

50

80

MURATA LQH32CN220

TAIYO YUDEN LB2012B220M

TAIYO YUDEN CB2012B220

4 LEDs

Figure 4a. Efficiency Comparison of Different Inductors (LT3465)

Figure 4b. Efficiency Comparison of Different Inductors (LT3465A)