SGM3128 Datasheet, PDF (7/10 Pages) SG Micro Corp – 3-Channel LowDropout Low Side White LED Driver

SGM3128
APPLICATION INFORMATION
Enable Input
Drive EN high to enable the device; drive EN low to force
LED1, LED2 and LED3 into a high-impedance state.
When driven high, EN draws 240μA to power the IC.
Driving EN low longer than 3ms will disable the device
and the typical supply current will be less than 1µA.
Input UVLO
The input operating voltage range of the SGM3128 is
2.5V to 5.5V. An input capacitor at the V_CC pin could
reduce ripple voltage. It is recommended to use a
ceramic 0.1μF or larger capacitance as the input
capacitor. This IC provides an under voltage lockout
(UVLO) function to prevent it from unstable issue when
startup. The UVLO threshold of input rising voltage is set
at 2.1V typically with a hysteresis 0.11V.
3-Channel Low Dropout
Low Side White LED Driver
LED Brightness Dimming Control
For controlling the LED brightness, the SGM3128 can
perform the dimming control by applying a PWM signal to
EN pin. When an external PWM signal is applied to the
EN pin, brightness of white LED is adjusted by the duty
cycle. The average LED current is proportional to the
PWM signal duty cycle. The magnitude of the PWM
signal must be higher than the minimum level of enable
input high level, in order to let the dimming control
perform correctly. The suggested PWM frequency range
is 20kHz to 200Hz.
SG Micro Corp
7
www.sg-micro.com