Introduction

　　The TPL0401 is an I2C bus controlled， single channel， linear-taper digital potentiometer with 128 wiper positions. TPL0401A/B have an end-to-end resistance of 10k ohms and the low terminal internally connected to ground. The position of the wiper can be adjusted using an I 2C interface. The TPL0401 is available in a 6-pin SC-70 package with a specified temperature range of –40°C to 125°C. The part has a 10k end-to-end resistance and can operate with a supply voltage range of 2.7V to 5.5V.

　　THE TPL0401EVM also consists of multiple other TI products （port expanders， LED drivers etc.）。 However， the scope of this document is to illustrate the use of the EVM to evaluate the TPL0401. The TPL0401EVM is designed to operate with the Texas Instruments LaunchPad （MSP-EXP430G2）。 The TPL0401EVM comes with a preprogrammed MSP430G2553 microcontroller which is to be inserted in the DIP socket on the LaunchPad. The LaunchPad can be separately purchased at www.ti.com/launchpad 。

　　The TPL0401EVM has three different evaluation modes：

　　Mode 1 – LED mode – This is the standard mode the TPL0401 comes up in when powered up. In this mode the TPL0401 devices are used to control the color mixing on the RGB LEDs. The DPOTs are used to set the current limit for the TLC59108 LED driver. This mode is and auto run mode that does not have any GUI control. The flashing lights and color mixing is controlled by the keys on the board and other TI products on the board.

　　Mode 2 – Adjustable voltage reference mode – in this mode the TPL0401 is used in conjunction with an LMV321 op amp as an adjustable voltage reference circuit.

　　Mode 3 – Variable gain mode – in this mode the TPL0401 is configured as part of a variable gain non-inverting amplifier. The gain of the amplifier can be controlled by a digital interface. This mode can be used to evaluate the bandwidth of the TPL0501.

　　The EVM is operated by connecting the LaunchPad to a PC that has Windows? （with .NET） via the USB Port. Other standard lab equipment such as Signal generator， multimeter， spectrum analyzer etc may be required for detailed analysis of the TPL0501 performance using this EVM.

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