六路输出可编程LED电流吸收 Six Output Programmable LED Current Sink
The LX1991 six channel current sink driver is ideal for controlling brightness and hue of high quality dimmable LED displays. High accuracy, dual mode dimming, and controlled current switching time provides consistent color hue, at brightness ratios of up to 1000:1, and keeps electro magnetic emissions in check. Its wide compliance voltage range combined with 43 volt breakdown capability make the LX1991 ideal for automotive in-dash displays.
**Precision current control:** Precision current mirror circuitry sets all channels to the same current with a single programming input. Sinking current value can be programmed up to 30 mA per channel with a single resistor or potentiometer from ISET+ to ISET-. Channel to channel matching is typically within ±1 percent of channel mean at the rated output current.
**Dual Mode Dimming:** Display dimming can be achieved by controlling either current amplitude or duty cycle, and both methods can be employed at the same time.
**1000:1 Dimming Range:** The DIG_DIM input accepts a TTL or CMOS logic signal that controls duty cycle of the output currents.
**Independent Channels:** The six channels feature independent regulation with respect to output voltage, so one does not affect the others. Any one or more outputs can be left unloaded without affecting current regulation of the other channels. Multiple channels can also be connected together to sink more current in a single load.
**EMI Control:** Rise and fall time of sink currents are precisely controlled by placing a capacitor on the SLOPE_C pin. Special control circuitry maintains symmetrical rise and fall times, preserving the LX1991’s ability to provide accurate output current response to very narrow input pulses on the DIG_DIM pin.
**Power Handling:** The LX1991 is supplied in a 4x4 MLPQ package capable of 1.5 watts dissipation.
**Logic Enable:** A separate input puts the LX1991 to sleep at less than 1 uA IDD.