The AAT2469/AAT2499 evaluation board is a hardware platform to evaluate the functions of the AAT2469 and AAT2499 devices. The AAT2469 is a dedicated TVLiteTM control IC for the AAT2499 TVLiteTM LED driver, which is a highly integrated two channel LED driver. The AAT2469 and AAT2499 operate over a common 4.5V to 5.5V range. The LED input voltage range, VLED, is determined by the highest VF (LED Forward Voltage) multiplied by the number of LEDs in a given string. The maximum VLED is limited to the AAT2499 BVDSS spec of 150V. The maximum VLED must be less than 150V to avoid damage to the AAT2499s on the demo board. The AAT2499 CSFBI input and CSFBO output provide a necessary feedback route when cascading multiple AAT2499s to provide a single voltage mode feedback for the AAT2469. The AAT2469 ICSFB provides a current mode feedback for a third party system power supply. Each current sink in the AAT2499 is programmable via the serial shift interface. The serial shift interface is controlled by the AAT2469. An AAT2469 can control up to 8 AAT2499s, or a total of 16 current sinks. The AAT2469 captures the current sink data via the SPI interface. Then the data is converted and is sent out to the AAT2499s via the serial shift interface. The speed of the serial shift interface is the same as the GSLCK frequency applied to the AAT2469. Full scale LED current is programmed using an external resistor on the AAT2499 RSET pin. The LED current can be scaled linearly from minimum to maximum setting current with the VREF input voltage. The AAT2469 supplies this VREF voltage that is controlled by the DOT correction register in the AAT2469 with 8-bit resolution. Both phase delay and grayscale clock (GS Clock) PWM on-time are user programmable with 12-bit resolution for each current sink bank. Timing and synchronization are determined by externally applied VSYNC and GSCLK signals. The AAT2469 is available in a standard SOP16 package. The AAT2499 is available in a standard SOP16 or SOP16-EP package. More details on the AAT2469 and AAT2499 can be found in the product datasheets. This document will cover the board schematic, layout guidelines and setup of a few key configuration registers to demonstrate the AAT2469 and AAT2499 driving LED strings with different brightness levels. The document includes scope shots to show the corresponding relationships between related waveforms.
| 应用技术支持与电子电路设计开发资源下载 | 版本信息 | 大小 |
| AAT2469 数据资料DataSheet下载:pdf | Rev.V2 | 2 页 |
