General Description
The TDK 5101 is a single chip ASK/ FSK transmitter for the frequency band 311-317 MHz. The IC offers a high level of integration and needs only a few external components. The device contains a fully integrated PLL synthesizer and a high efficiency power amplifier to drive a loop antenna. A special circuit design and an unique power amplifier design are used to save current consumption and therefore to save battery life. Additionally features like a power down mode, a low power detect and a divided clock output are implemented. The IC can be used for both ASK and FSK modulation.

Features
■ fully integrated frequency synthesizer
■ VCO without external components
■ high efficiency power amplifier
■ frequency range 311 ... 317 MHz
■ ASK/FSK modulation
■ low supply current (typically 7mA)
■ voltage supply range 2.1 ... 4 V
■ temperature range -40 ... +125°C
■ power down mode
■ low voltage sensor
■ programmable divided clock output for µC
■ low external component count

Applications
■ Keyless entry systems
■ Remote control systems
■ Alarm systems
■ Communication systems