Texas Instruments LMV242x Log RF Power Detectors
Texas Instruments LMV242x Log RF Power Detectors are single-output (LMV2421) and dual-output (LMV242) power amplifier (PA) controllers. These devices are intended for use within GSM and GPRS mobile phones and an RF transmit power control loop for RF PA control. The LMV242x supports all single-supply PAs, including HBT, InGaP, and bipolar power amplifiers. The devices operate with 2.6V to 5.5V in a single supply. The LMV2421 PA controller includes a ramp filter, a log RF detector, and an output driver that functions as an error amplifier.
The dual-output LMV242 includes two selectable output drivers to control two different PAs. The LMV2421 input interface consists of one digital input, two analog inputs, and two digital inputs for the LMV242. The analog inputs are the ramp voltage input and the RF input. The digital inputs perform the function of transmit/shutdown enable and band select (LMV242 only). The LMV242x is active when TX_EN = high. The device is in a low-power-consumption shutdown mode when TX_EN = low. The outputs are pulled low to the minimum output voltage during shutdown. The band select (LMV242 only) function enables either OUT1 when BS = high or output OUT2 when BS = low. The output not enabled is pulled low to the minimum output voltage. Individual PA characteristics are accommodated by a user-selectable external RC combination.
The Texas Instruments LMV242x is offered in a 10-lead WSON package and is an excellent choice for small-footprint PA module systems.
Features
- 450MHz to 2GHz operation
- 50dB log RF detector
- Integrated ramp filter
- External loop compensation option
- Accurate temperature compensation
- Shutdown mode for power save in the RX slot
- GPRS compliant
- Support of InGaP HBT, bipolar technology
- 3mm × 3mm WSON package
Applications
- GSM, GPRS, TDMA, TD-SCDMA mobile phone
- Pulse RF control
- Wireless LAN
- GSM and GPRS power amplifier module
- Transmit module
Functional Block Diagrams
