An LED current control device (100) includes an array of one or more LEDs
(10) electrically connected to a current-sensing element (20). A sense
signal produced by the current-sensing element may be amplified by a
single-ended amplifier (30) and sent to a switching controller (40 and
50). The switching controller may perform hysteretic control on the
amplified sense signal by controlling a switching element (60) to turn on
and off. The on and off states of the switching element respectively
enables and disables an external power supply (V.sub.EXT) for the LED
array. As such, hysteretic control may be performed on the current
flowing through the LEDs.