LT3003 Просмотр технического описания (PDF) - Linear Technology

Номер в каталоге

Компоненты Описание

производитель

LT3003

3-Channel LED Ballaster with PWM

Linear Technology 

LT3003

TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C unless otherwise noted.

VIN Quiescent Current vs ILED

35

30

25

20

15

10

5

0

50 100 150 200 250 300 350

ILED (mA)

3003 G07

VIN Shutdown Current vs VIN

16

SHDN = 0

14

12

10

8

6

4

2

0

3 8 13 18 23 28 33 38

VIN (V)

3003 G08

PIN FUNCTIONS

LED1 (Pin 1): Controlled current input for a string of LEDs

with a cathode lead connected to the pin. Connect the first

string of LEDs to this pin.

LED2 (Pin 2): Controlled current input for a string of LEDs

with a cathode lead connected to the pin. Connect the sec-

ond string of LEDs to this pin.

LED3 (Pin 3): Controlled current input for a string of LEDs

with a cathode lead connected to the pin. Connect the third

string of LEDs to this pin.

VMAX (Pin 4):

• Boost: Connect to VOUT

• Buck Mode: Connect to Input Supply

• Buck-Boost Mode: Connect to VOUT

VIN (Pin 5): Input Supply, Upper Rail. This pin must be

locally bypassed with a capacitor to ground. VIN powers

the internal control circuitry.

• Boost: Connect to Input Supply

• Buck Mode: Connect to Input Supply

• Buck-Boost Mode: Connect to VOUT

PWM (Pin 6): Input Pin for PWM Dimming Control. A

PWM signal above 0.5V (on threshold) turns the LT3003

channels on. A PWM signal below 0.5V completely discon-

nects each LED string. If the application does not require

PWM dimming, then the PWM pin can be left either open

(an internal 10µA source current pulls PWM high) or it

can be connected to a supply between 0.5V to 15V.

OT1 (Pin 7): Overtemperature Output. OT1 pulls 100µA

from the pin when the junction temperature exceeds

125°C. The part has to cool down by 6°C for the flag to

reset; ideal for providing an overtemperature flag to the

system microprocessor.

OT2 (Pin 8): Overtemperature Output. OT2 Pulls 300µA

from the pin when the junction temperature exceeds

125°C. The part has to cool down by 6°C for the flag to

reset; ideal for connecting to the switching regulator gm

error amplifier output to defeat switching.

SHDN (Pin 9): Micropower Shutdown Pin. Below 0.7V

shuts down the IC. Typically IVIN = 4µA for SHDN = 0V.

• Boost: Connect to System Shutdown Signal or VIN

• Buck Mode: Connect to System Shutdown Signal

or VIN

• Buck-Boost Mode: If PWM dimming, connect to PWM

(Pin 6); if no PWM dimming, connect to system shut-

down signal or VIN

3003fa

4

Share Link: