Micrel Inc.

MIC2845/46

January 2008

5

M9999-010808-A

WLED Current Sinks

Parameter

Conditions

Min

Typ

Max

Units

Current Accuracy

(5)

-5

+5

%

Matching

(6)

-3.6

-5.5

+3.6

+5.5

%

%

Drop-out

50

100

mV

Ground/Supply Bias Current

1.0

mA

Shutdown Current

(current source leakage)

0.01

1

µA

MIC2845- PWM Dimming

Logic Low

0.2

V

Logic High

1.2

V

Enable Input Current

0.01

1

µA

Minimum Pulse Width

10

µs

Current Source Delay

(50% levels)

Shutdown to on

(5)

125

1

0.5

1

1

µs

µs

µs

µs

µs

Current Source Transient Time

(10%-90%)

1

1

0.3

0.3

µs

µs

µs

µs

Stand-by to shutdown time

20

TBD

40

ms

MIC2846- Digital Dimming

Logic Low

0.2

V

Logic High

1.2

V

VDC Enable Input Current

0.01

1

µA

Time DC pin is low to put into shutdown

1260

µs

Time DC pin is low to change to Count Up Mode

100

160

µs

Time DC pin is low to change to Count Down Mode

420

500

µs

Time for valid edge count; Ignored if outside limit range

1

32

µs

Time DC pin must remain high before a mode change

can occur

140

µs

First down edge must occur in this window during

presetting brightness

35

50

µs

Delay from DC is high to start up

140

µs

Notes:

5. As determined by average current of all channels in use and all channels loaded.

6. The current through each LED meet the stated limits from the average current of all LEDs.

7. Maximum differential in forward voltage anticipated from the LED with the highest forward voltage to the LED with the lowest forward voltage at

nominal current.

9. Dropout voltage is defined as the input-output differential at which the output voltage drops 2% below its nominal value measured at 1V differential.