The HV9980 is a fully integrated,
3-channel, peak-current PWM controller for driving buck converters in
constant output current mode. It is optimized for use with a large array
of LED strings, where multiple HV9980 ICs share a common clock and the
voltage reference is external to the HV9980 for improved output current
accuracy and uniform illumination.
The HV9980 has three built-in
160V, 25 ohm switching MOSFETs that save board space and overall system
cost. The three output currents can be individually dimmed using either
linear or PWM dimming. In addition, the fast transient response of the
IC's current mode control supports local dimming and scanning mode capability,
ideal for backlighting large screen LCD TVs. Each CS input is also equipped
with a reset switch that can be used for an optional external slope
compensation circuit to achieve a duty cycle greater than 50%. The output
signal polarity select pin (POL) is included for inverse polarity of
the output signal.
Additional features of the
HV9980 include output short-circuit and over-temperature protection.
The HV9980 delivers excellent performance while providing the most cost-effective
solution for LED-backlit systems.
