MAX9591:14 Programmable Gamma Reference Buffers with Four Static References for TFT-LCD Displays

Programmable Gamma Buffer with Column Driver Protection

The MAX9591 provides 14 programmable voltage references and four static voltage references for gamma correction in TFT-LCD displays. Two register banks are provided to store two sets of gamma reference values that are programmed into the banks through an I²C interface. The outputs can switch between gamma reference values in 0.5µs. The 14 programmable reference voltages are divided evenly into seven upper and seven lower voltages for the upper and lower gamma curves of LCD column drivers. Each gamma reference voltage has an 8-bit digital-to-analog converter (DAC) with an isolation buffer associated with it to ensure stable operation. Therefore, the reference voltages remain stable without synchronizing to the LCD horizontal timing. In addition, each buffer is able to provide a high current that further ensures a stable voltage when critical levels and patterns are displayed. The reference voltages ramp up proportional to AVDD during startup and gamma buffers wake up in high impedance until all of the registers are written. This protects the LCD column drivers from high transient currents and reverse bias conditions. The MAX9591 is available in a 38-pin TQFN package and is specified for operation over the -40°C to +85°C temperature range.

Key Features
  • 20V (max) Operating Voltage
  • 14 Programmable Reference Voltages
  • Four Static Reference Voltages
  • Independent DACs
  • 8-Bit Resolution per Channel
  • Two Register Banks for Two Sets of Gamma Values
  • Fast Switching Between Gamma Values
  • Output Swing within 100mV of Rails
  • 400mA Peak Current on Reference Channels and DAC Channels 1, 7, 8, and 14
  • 200mA Peak Current on DAC Channels 2–6, 9–13
  • Startup Column Driver Protection
MAX9591: Typical Operating Circuit
MAX9591: Typical Operating Circuit
Applications/Uses
  • Industrial Reference Voltage Generators
  • TFT-LCD Displays
Parametrics
Part NumberTotal ChannelsProgrammable ChannelsResolution
(bits)
Integrated Nonvolatile MemoryMemory BanksVCOM CalibratorVCOM BufferInterfaceVSUPPLY
(V)
IQ
(mA)
Oper. Temp.
(°C)
Package/PinsBudgetary
Price
See Notes
MAX959118148No2NoNoI2C9 to 2021-40 to +85TQFN/38$1.30 @1k
Design kits & evaluation modules
Quality and Environmental Data
Related Products
  • MAX5679:Digitally Programmable LCD Gamma Reference Generator with Digital Voltage Reference
  • MAX9590:14 Programmable Gamma Reference Buffers with 4 Static References for TFT-LCD Displays
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX9591ETU+Active: Data sheet on request onlyTQFN,;38 pin;36.2 mm²-40°C to +85°CLead Free
MAX9591ETU+TActive: Data sheet on request onlyTQFN,;38 pin;36.2 mm²-40°C to +85°CLead Free
MAX9591.pdf MAX9591
典型工作电路 MAX9591