2 TPS61376 in Barcode Scanner Application

One typical application that requires the input average current limit function is barcode scanner. Barcode scanners are also known as barcode readers, which are input devices that converts barcode information into computer-acceptable information using the principle of photo-electricity, commonly used in libraries, hospitals, bookstores, supermarkets, logistics and other industries.

So how does the boost converter TPS61376 help in a more integrated barcode scanner design? #GUID-365E28A1-0F99-4C8D-A1A2-6D222FE29DCF shows a typical power tree of a barcode scanner. Barcode scanners usually have high power Flash LEDs for light transmission. The voltage depends on the number of LEDs in series and the LED current is relatively high, typically 2 to 3 A or even higher. The power supply for the barcode scanner is either USB or battery. For the limitation of maximum 500 mA current capability, the USB interface cannot provide such an instantaneous high current, so a buffer capacitor is usually incorporated into the system to provide instantaneous energy.

TPS61376 can be used to limit the input average current to protect the USB from crashing and boost the input voltage rail to a higher output voltage rail to charge the large output capacitors. The input average current limit is active during normal operation as well as during startup. This effectively limits the inrush current, and can also be used to reliably charge heavy loads, from a power source with limited current capability. The TPS61376 has programmable input average current limit range from 0.1A to 3A with an accuracy up to ±2.5%.

With all these features of input average current limit in TPS61376, a more integrated barcode scanner design can be achieved which can replace outdated designs that are using additional e-fuse or switch to implement input current limit.