1MHz PWM Boost Converter for 1.5A

White LED Camera Flash

_______________________________________________________________________________________

5

400

0

110

100

MOVIE-MODE LED CURRENT

vs. MOV RESISTANCE

100

Ω)

200

300

50

150

250

350

1600

0

110

100

FLASH-MODE LED CURRENT

vs. FLSH RESISTANCE

400

Ω)

800

1200

200

600

1000

1400

Typical Operating Characteristics (continued)

Pin Description

PIN

NAME

FUNCTION

1

COMP

Compensation Input. Connect a 0.1µF ceramic capacitor from COMP to GND for regulator stability.

2

EN1

Enable Input 1. EN1 and EN2 set the operating mode (see Table 1).

3

EN2

Enable Input 2. EN1 and EN2 set the operating mode (see Table 1).

4

MOV

Movie Current Program Input. Connect a resistor from MOV to GND to set the LED current in movie mode.

Ω.

5

FLSH

Flash Current Program Input. Connect a resistor from FLSH to GND to set the LED current in flash mode.

Ω.

6

GND

Analog Ground. Connect GND to the exposed paddle directly under the IC.

7

LGND

LED Current Regulator Ground. Connect LGND to the ground plane on the PC board.

8

LED

LED Current Regulator. Connect LED to the cathode of the external LED. LED is high impedance during shutdown.

9, 10

PGND

Power Ground. Connect PGND to the input capacitor ground. Also, connect PGND to the PC board ground plane.

11, 12

LX

Inductor Connection. Connect LX to the switched side of the inductor. LX is internally connected to the

drains of the internal MOSFETs. Both MOSFETs are off during shutdown.

13

OUT

Regulator Output. Connect OUT to the anode of the external LED. Bypass OUT to PGND with a 10µF or

larger ceramic capacitor. During shutdown, OUT is one body-diode drop below the input voltage.

14

OUTS

Output Sense and IC Supply Input. Connect OUTS to OUT at the output bypass capacitor. The IC’s operating

power is supplied from OUTS.

—EP

Exposed Paddle. Connect the exposed paddle to GND directly under the IC and to a large PC board

ground plane for increased thermal performance.