SM8150A

SEIKO NPC CORPORATION —5

10. RECOMMENDED OPERATING CONDITIONS

VIN1 = VIN2 = VIN3, GND = PGND = 0V

When the white LED drive current is increased, the required supply voltage also increases. The supply is automatically switched in charge pump boost

mode, and cannot be manually selected. The forward-bias voltage drop VF of the LED is assumed to be

≤ 3.5V.

*2. Torch and Strobe

Pin DIN7 is provided for connection to a high-current white LED. Two types of light modulation (dimming) data are available, switched by the SBN input

voltage. When SBN is HIGH, torch mode is selected. When SBN is LOW, strobe mode is selected. The recommended operating condition is high cur-

rent with short ON times in strobe mode, and low current with longer ON times in torch mode. In strobe mode (SBN = LOW), high-current supply is the

main priority and, therefore, the current consumption is not optimized (see “Torch/Strobe Selecting”).

Parameter

Pin

Symbol

Conditions

Rating

Unit

min

typ

max

VIN1 to 3

2.7

3.6

4.6

V

3.0

3.6

4.6

V

3.3

3.6

4.6

V

Logic operating voltage

VEN

1.8

2.8

4.6

V

Input voltage

SBN, SCL,

SDA

0

−

V

DIN7

−−

250

ms

−−

150

mA

Operating temperature

−

Ta

−30

25

+85

°C

SBN

Torch

Strobe

Dimming

Recommended operating conditions

DIN7

− Enable

1

1

1

*

*

1

*

*

H

ON

OFF

Torch

L

OFF

ON

Strobe

Operating time

< 250ms

DIN7

− Disable 1 1 1 *

*

0

*

*

H

OFF

OFF

−−

L

OFF

OFF

−−

0

100

200

300

400

500

2.5

3

3.5

4

4.5

5