TCS3404CS datasheet(33/41 Pages) AMSCO

33 / 41 page

TCS3404, TCS3414

DIGITAL COLOR SENSORS

TAOS137A − APRIL 2011

E 2011, TAOS Inc.

The LUMENOLOGY

r Company

www.taosinc.com

APPLICATION INFORMATION: HARDWARE

Power Supply Decoupling and Application Hardware Circuit

The power supply lines must be decoupled with a 0.1

μF capacitor placed as close to the device package as

possible (Figure 28). The bypass capacitor should have low effective series resistance (ESR) and low effective

series inductance (ESI), such as the common ceramic types, which provide a low impedance path to ground

at high frequencies to handle transient currents caused by internal logic switching.

TCS3404/14

VBUS

VDD

0.1

SCL

SDA

RPI

INT

Figure 28. Bus Pull-Up Resistors

Pull-up resistors (Rp) maintain the SDA and SCL lines at a high level when the bus is free and ensure the signals

are pulled up from a low to a high level within the required rise time. For a complete description of I2C maximum

and minimum Rp values, please review the NXP I2C design specification at http://www.i2c−bus.org/references/.

A pull-up resistor (RPI) is also required for the interrupt (INT), which functions as a wired-AND signal in a similar

fashion to the SCL and SDA lines. A typical impedance value between 10 k

Ω and 100 kΩ can be used. Please

note that while the figure above shows INT being pulled up to VDD, the interrupt can optionally be pulled up to

VBUS.

TCS3404CS Fiches technique(PDF) 33 Page - ams AG