LT1942
PI FU CTIO S
LED1 (Pin 18): First Input of Current Mirror for an LED
String. Connect the negative end of first string of LEDs to
this pin. If not in use, leave floating.
SW4 (Pin 19): Switch Pin for LED Switcher. This is the
collector of an internal NPN power switch. Minimize the
metal trace area connected to this pin to minimize EMI.
SW1 (Pin 20): Switch Pin for AVDD Switcher. This is the
collector of an internal NPN Power switch. Minimize the
metal trace area connected to this pin to minimize EMI.
PGND14 (Pin 21): Power Ground for LED Switcher and
AVDD Switcher. Tie directly to local ground plane.
VCC (Pin 22): Input Supply. Must be locally bypassed.
D2 (Pin 23): Anode Connection of Internal Schottky Diode
for VOFF Switcher.
SW2 (Pin 24): Switch Pin for VOFF Switcher. This is the
collector of an internal NPN Power switch. Minimize the
metal trace area connected to this pin to minimize EMI.
SGND (Pin 25): Signal Ground. This is the Exposed Pad,
which must be soldered directly to a local ground plane to
achieve optimum thermal performance.
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