Constant-Current 3-Ampere PWM Dimmable

Buck Regulator LED Driver

A6211

4

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

otherwise noted

Characteristics

Symbol

Test Conditions

Min.

Typ.

Max.

Unit

Input Supply Voltage

6

–

48

V

–

5.3

–

V

–

150

–

mV

VIN Pin Supply Current

–

5

–

mA

VIN Pin Shutdown Current

EN shorted to GND

–

1

10

μA

BOOT Switch Current Limit Threshold

3.0

4.0

5.0

A

Buck Switch On-Resistance

R

DS(on)

–

0.25

0.4

Ω

1.7

2.9

4.3

V

–

370

–

mV

Switching Minimum Off-Time

–

110

150

ns

Switching Minimum On-TIme

–

110

150

ns

Selected On-Time

800

1000

1200

ns

Regulation Comparator and Error Amplifier

Load Current Sense Regulation

Threshold

187.5

200

210

mV

Load Current Sense Bias Current

–

0.9

–

μA

Internal Linear Regulator

VCC Regulated Output

5.0

5.3

5.6

V

VCC Current Limit*

5

20

–

mA

Enable Input

Logic High Voltage

1.8

–

–

V

Logic Low Voltage

–

–

0.4

V

EN Pin Pull-down Resistance

–

100

–

kΩ

Maximum PWM Dimming Off-Time

Measured while EN = low, during dimming

control, and internal references are powered-on

10

17

–

ms

Thermal Shutdown

Thermal Shutdown Threshold

–

165

–

°C

Thermal Shutdown Hysteresis

–25–°C

*The internal linear regulator is not designed to drive an external load