Lower wireless-power-charging losses with fast-charge receivers

June 02, 2014 // By Graham Prophet
TI's small 5W receivers enable faster, cooler and more power efficient charging for Qi-enabled smartphones and other portable electronics.

Offered as the most power-efficient 5-W wireless power receivers that support the Wireless Power Consortium (WPC) Qi 1.1 standard, Texas Instruments’ bq51020 and bq51021 allow consumers to charge their Qi-compliant mobile phones, tablets, power banks and other electronics faster, cooler and more efficiently compared to other available wireless power solutions.

The bq51020 and bq51021 single-chip receivers have a programmable output voltage up to 8V and low on-resistance MOSFETs to reduce power loss by as much as 50%, compared to existing solutions in the market. The bq51021 features an I 2C interface, which allows system designers to implement foreign object detection and a "pad-detect" feature that makes aligning the receiver with the charger easier.

The parts achieve up to 96% power efficiency, and an adjustable output voltage helps reduce power loss by as much as 50%; and reduces temperature rise by 35% compared to other solutions. The single-chip 5-W receivers provide rectification, regulation, and digital control and communications to support the Qi 1.1 specification. The 3.6 by 2.9 by 0.5-mm single-chip wireless power receiver achieves a solution size of 75 mm 2 without the need for an inductor.

These receivers join the bq51221, which TI introduced in February 2014 as the first dual-mode 5-W wireless power receiver to support Qi and the Power Matters Alliance (PMA) specifications. TI also recently released the bq51003 2.5-W receiver for small portable and wearable applications. The bq51020EVM-520, bq51221EVM-520 and bq51003EVM-765 evaluation modules assist with wireless power designs.

Pricing is $2.50 for the bq51020, $2.70 for the bq51021 and $3.00 for the bq51221 (1,000). The low-power bq51003 receiver comes in a 28-ball, 1.9 by 3.0-mm chip scale package at $1.30.

Texas Instruments; www.ti.com/bq51020-pr