Driver IC ILI9488

 The ILI9488 is a 16.7M single-chip SoC driver for a-Si TFT liquid crystal display panels with a resolution of 320(RGB) x 480 dots. The ILI9488 is comprised of a 960-channel source driver, a 480-channel gate driver, 345,600 bytes GRAM for graphic data of 320 (RGB) x 480 dots, and power supply circuit. The ILI9488 supports parallel DBI Type B 8-/9-/16-/18-/24-bit data bus interfaces and DBI Type C 3-/4-line serial peripheral interfaces (SPI) to input commands. The ILI9488 supports DPI (16-/18-/24-bit) data bus for video image display. For MIPI*-DSI* high-speed interface mode, the ILI9488 also provides one data lane and one clock lane that can support up to 500Mbps on MIPI-DSI link. The ILI9488 can operate with 1.65V I/O interface voltage and supports a wide range of analog power supplies. The ILI9488 supports 8-colors display and sleep mode power management functions, ideal for portable products where battery power conservation is desirable, such as digital cellular phones, smart phones, MP3 players, personal media players and similar devices with color graphics displays.

 Notes: 

  MIPI: Mobile Industry Processor Interface 

  DSI: Display Serial Interface

  

 1. Display resolution: 320 (RGB) (H) x 480 (V)

 2.Display color modes:

  a.Full color modes: 

                     16.7M colors with dithering function (24-bit data, R: 8-bit, G: 8-bit, B: 8-bit) 

                      262K colors (18-bit data, R: 6-bit, G: 6-bit, B: 6-bit)

  b. Reduced color modes: 

       65K colors (16-bit data, R: 5-bit, G: 6-bit, B: 5-bit)

       8 colors (3-bit data, R: 1-bit, G: 1-bit, B: 1-bit) 

  

  2. Display module: 

 a. On-chip Frame Memory size 345,600 bytes, 320 (RGB) (H) x 480 (V) x 18 bits

 b. Supports 960 source channel outputs Supports up to a maximum of 480 gate lines Supports 24-bits input image function

 c. Supports column/1-/2-dot inversion On-module DC VCOM control (-2 to 0V common electrode output voltage range)

 d. Source/VCOM/Gate power supply voltage 

                         DDVDH – GND = 4.5 to 6V

     DDVDL – GND = -6 to -4.5V

     VCL – GND = -3 to -2V

     DC VCOM – GND = -2 to 0V, a step = 16mV

     VREG1OUT – GND = 3.625 to 5.5 V

     VREG2OUT – GND = -5.5 to -3.625V

     VGH – GND = 10 to 20V 

     VGL – GND = -15 to -5V 

  3. Display Interface types: 

  a. MIPI-DBI (Display Bus Interface)

     Type B (i-80 system), 8-/9-/16-/18-/24-bit bus

     Type C (Serial data transfer interface, 3/4-line SPI)

 b. MIPI-DPI (Display Pixel Interface)

      Supports 24 bit/pixel (R: 8-bit, G: 8-bit, B: 8-bit)

      Supports 18 bit/pixel (R: 6-bit, G: 6-bit, B: 6-bit)

      Supports 16 bit/pixel (R: 5-bit, G: 6-bit, B: 5-bit)

  c. MIPI-DSI (Display Serial Interface)

      Supports one data lane/maximum speed 500Mbps

      Supports DSI version 1.01

      Supports D-PHY version 1.00 

  4. Input power 

 a. Low operating power supplies

     IOVCC = 1.65 to 3.3V (Interface I/O)

     VCI = 2.5 to 3.3V (Analog)

     OTP programming voltage (DDVDH) = 7V

 5. Power saving modes:

 a. Deep-standby mode

  b. Sleep mode

 5. Other on-chip functions/Miscellaneous

  a. Supports partial display mode

  b. Supports inversion mode

 c. Oscillator for display clock generation LVD function (GAS bit) prevents image sticking for abnormal power off

  d. Supports DC VCOM driving

  e. DC VCOM voltage generator and adjustment

  f. OTP memory store initialization register settings (MATCDL, VRH1, VRH2 and BT)

  g. MTP (provides 4 times OTP to store DC VCOM setting, ID1/ID2/ID3 setting)

  h. Supports CABC function

  i. Supports 3-Gamma DGC function

  j. Supports dither function. (The dither function is only available in Bypass mode of DPI 24-bit and MIPI-DSI.)

  k. Supports color enhancement function

 

  6. Operate temperature range: -40 to 85 ℃ 

 Notes:

  CABC: Content Adaptive Brightness Control

 DGC: Digital Gamma Correction

 LVD: Low Voltage Detection

 MTP: Multiple Time Programming

  OTP: One Time Programming

 Block Diagram 

  System Interface

  The interface operating mode (DBI, DPI or DSI) is selected by hardware pins IM [2:0], as shown in Table 1 below

 The ILI9488 supports MIPI DBI Type B (8-/9-/16-/18-/24-bits) that uses command method which has an 8-bit index register (IR) and an 8-bit control register (CR). The ILI9488 also has an 18-bit write-data register (WDR) and read-data register (RDR). The WDR is the register to temporarily store data to be written to control registers and the internal GRAM. The RDR is the register to temporarily store data read from the GRAM. Data from the MPU to the internal GRAM are first written to the WDR and then automatically written to the internal GRAM in the internal operation. Data are read via the RDR from the internal GRAM. Therefore, invalid data are read out to the data bus when the ILI9488 reads the first data from the internal GRAM. Valid data are read out after the ILI9488 performs the second read operation.

 Video Image Interface (TE-Signal and DPI)

 When the DBI is selected, display data is written in synchronization with the TE signal which is generated from the internal clock to prevent flicker on the panel.

 When the DPI is selected, externally supplied VSYNC, HSYNC, and DOTCLK signals will drive the chip. Display Data (DB [23:0]) is written in synchronization with those synchronous signals after Data Enable (ENABLE). This enables updating image data without flicker on the panel.

 Address Counter (AC)

 The Address Counter (AC) assigns an address to the internal GRAM. When the index of the register for setting a RAM address in the AC is written to the IR, the address information is sent from the IR to the AC. When writing data to the internal GRAM, the address in the AC is automatically increased/decreased by 1. The window address function enables writing data only in the rectangular area arbitrarily set by users on the GRAM.

 Graphic RAM(GRAM)

 The GRAM is used to store the display pattern data with a maximum of 345,600 bytes for 320 (RGB) x 480 display resolution.

 Grayscale Voltage Generating Circuit

 The Grayscale Voltage Generating Circuit generates a liquid crystal drive voltage that corresponds to the grayscale level setting in the Gamma correction register. The ILI9488 can display 262k colors at maximum.

 Power Supply Circuit

  The LCD drive power supply circuit generates VREG1OUT, VREG2OUT, VGH, VGL, and DC VCOM levels to drive the TFT LCD panel.

  Timing Generating

  The Timing Generator generates timing signals for internal circuits, such as the internal GRAM. Timing for display operation, such as RAM read operation, and timing for internal operations, such as RAM access by the MCU, is outputted separately so that they do not interfere with each other.

 Oscillator

 The ILI9488 includes an RC oscillator circuit. Command settings are used to change the frame frequency.

 Panel Driver Circuit

  The LCD Driver Circuit has a 960-channel source driver (S1~S960) and a maximum of 480 gate lines (G1~G480). When 320 (RGB) pixels of data are input, the display pattern data is latched. The voltage is output from the source driver according to the latched data.

 MIPI-DSI Controller Circuit

  The MIPI-DSI Controller Circuit consists of a D-PHY controller, Protocol Control Unit (PCU), Packet Processing Unit (PPU), ECC generating circuit, internal data/command buffer, and analog transceiver. The D-PHY controls communication with the analog block, and the ECC generating circuit generates the ECC to check the outgoing data stream for accuracy of the receiving data packet. The PCU controls outgoing and incoming data streams, and the PPU controls packet distribution and merging. The internal data/command buffer is used for temporary storage of incoming commandsand display data.