The ISL97522 represents a 4-channel supply control IC for use in large panel TFT-LCD displays. Supporting inputs from 4.5V to 13V, the ISL97522 includes a boost controller to achieve the required A_VDD output voltage. Both V_ON and V_OFF are generated using off-chip charge-pumps which are then post regulated using on-board LDO controllers.

The logic supply is generated using an internal nonsynchronous buck controller. This controller runs at 180° out of phase with the A_VDD supply to minimize input noise.

The A_VDD, V_OFF, and V_ON outputs are automatically sequenced as A_VDD, V_OFF, and V_ON. By using an optional external series transistor with A_VDD (Q1), the start-up sequence can be adjusted to V_OFF, A_VDD and then V_ON. A V_ON slicing circuit is also included to reduce LCD flicker.

The ISL97522 also incorporates a fault protection circuit that can disable the IC and turn off all outputs when an output short is detected. (Note that to protect A_VDD a single external transistor is required).

• 4.5V to 13V input
• Boost controller for A_VDD
• Regulated LDOs for V_OFF and V_ON
• Buck controller for logic output
• V_ON slicing circuit
• Fully fault-protected
• Programmable sequence
• 1MHz switching frequency
• 38 Ld QFN package
• Pb-free plus anneal available (RoHS compliant)

• LCD-TVs (up to 50"+)
• LCD monitors (15"+)
• Industrial/medical LCD displays