Product News Power Electronics Wireless charging
Linear Technology Corporation now joins the wireless battery charging space with the introduction of its LTC4120. This device combines a wireless power receiver with a constant-current/constant-voltage battery charger, functioning as the receive circuit component in a wireless power transfer system; comprised of transmit circuitry, transmit coil, receive coil and receive circuitry.
This device is said to work well with the company’s discrete resonant trans- mitter reference design or with advanced off-the-shelf transmitters designed and manufactured by Power- byProxi, a New Zealand-based company in wireless power solutions. These PowerbyProxi transmitters are claimed to offer advanced features, in- cluding simultaneous charging of mul- tiple receivers with a single transmitter and foreign object detection to prevent excessive heating during transmit faults. The company’s LTC4120 accepts a
rectified 4.2V to 40V input from the receive coil to power a full-featured constant-current/constant-voltage 400mA battery charger. Linear Technology Corporation
www.linear.com Enter 214
TI launches new envelope tracking DC/DC converter for 3G and 4G LTE smartphones
by some 25 percent. The LM3290 and LM3291, which support battery voltages down to 2.5V, provide high efficiency at higher power output levels and high PAR, while meeting stringent receive band noise requirements in all LTE bands.
To improve battery life, Texas Instruments has introduced a new envelope tracking power supply device that supports 3G and 4G LTE multi-mode, multi- band RF power amplifiers used in smartphones and tablets. The new LM3290 step-down converter with integrated DC boost and accompanying LM3291 linear amplifier support the use of enve- lope tracking techniques in RF transmitters. This helps to reduce the power amplifier temperature by 20
C and has the potential to reduce overall power consumption
0
Improved bandwidth and battery voltage flexibility is achievable as the device manages all 3G and 4G LTE bandwidths up to 20MHz and battery voltages from 2.5V to 5V.
The added feature of envelope tracking is said to help reduce heat and power consumption by as much as 25 percent; and achieves greater than 90 percent efficiency using advanced power tracking for LTE 25RB. With the uses of this device smartphones and tablets do not need to depend on maximum power reduction when battery power is low. The integrated DC boost converter in the LM3290 provides maximum transmit
power – supporting higher LTE data rates even at lower battery voltage levels.
An analogue and digital inter- face supports the MIPI eTrak analogue differential front end interface for envelope tracking and a 1.8-V MIPI RFFE digital interface to simplify integration with the industry’s newest RF platforms. These devices’ also allow easy transition between envelope tracking and average power tracking operating modes. They are capable of providing high efficiency, low noise, low output impedance and low output ripple voltage at high LTE bandwidths (LTE10 and 20). The solution supports a minimum bandwidth of 75MHz, which is claimed as an industry first when using envelope track- ing - providing high accuracy with good adjacent channel leak- age ratio and noise performance. Texas Instruments
www.ti.com Enter 215
Crystals, Oscillators and Filters
LOW JITTER
Two new ranges of high precision low jitter oscillators are available on very quick delivery times — typically as little as 5 to 10 days. HTQF and HPQF series offer a low cost and technically superior solution for new and existing designs with low current consumption, wide operating frequency ranges and an integrated jitter performance of 0.1ps and 0.6ps rms respectively.
SMALLEST CRYSTAL
Our smallest SMD crystal yet – just 2.05 x 1.65mm with height of 0.6mm – an ideal component solution for restricted space applications requiring very low mass. Hermetically sealed, the X21 offers high resistance to shock and vibration allied to an extremely low ageing
characteristic. Ideal for use in miniaturised hand-held equipment and similar high density applications.
Tel: +44(0)1460 230000
www.euroquartz.co.uk Enter 16 Electronics JULY/AUGUST 2012 Enter 17 23
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36