High Accuracy Envelope Tracking for LTE Smartphones and Modems

The NCT-L1300 is a high efficiency Envelope Tracking (ET) power supply that supports handset Power Amplifiers (PA) modulated up to 20MHz Bandwidths (e.g. 100 RB LTE).

In ET mode the boost-capable architecture allows peak voltages of up to 4.5V with wide swing range to be supplied to PAs, allowing a wider selection of PA devices to be considered. It enables either higher load-line, wide bandwidth ET PAs or more linear power to be achieved from more conventional PAs.

The modulation envelope inputs support a differential input of +/-1V consistent with the OpenET Class 2.0 specification. The ETPS has a differential gain of 2.7.

The NCT-L1300 also supports a lower power Average Power Tracking (APT) mode to maintain high system efficiencies at reduced RF transmit powers.

The NCT-L1300 is controlled by a MIPI RFFE 1.10 standard 2-wire serial interface bus at 1.8V. The operating mode of the ETPS can be controlled with a single MIPI RFFE write.

The device is provided as a WLCSP with a 0.4mm pitch.

Features: 

• High efficiency Buck/Boost Envelope Tracking Power Supply (ETPS)
• Supports IsoGain™ operation with a 20MHz fully-loaded LTE Channel
• Wide input supply (VBATT) voltage range (2.5V to 5.25V)
• Peak output voltage in ET mode up to 4.5V with an output swing range of 3.8V
• RMS output power in ET mode 1.2W
• Peak output power in ET mode 4.5W
• MIPI RFFE control interface – simple single-write mode change
• Low quiescent current in standby mode