The ADF7901 is a low power OOK/FSK UHF transmitter designed for use in RF remote control devices. It is capable of frequency shift keying (FSK) modulation on eight different channels, selectable by three external control lines. OOK modulation is performed by modulating the PA control line. The on-chip VCO operates at 2x the output frequency. The division by 2 at the output of the VCO reduces the amount of PA feedthrough. As a result, OOK modulation depths of greater than 50 dB are easily achievable. The FSK_ADJ and ASK_ADJ resistors can be adjusted in the system to optimize output power for each modulation scheme. An additional 1.5 dB of output power is provided for the lower bank of channels to adjust for antenna performance. The CE line allows the transmitter to be powered down completely. In this mode, the leakage current is typically 0.1 A.