The APL1257 from ASB Inc. is a Frequency Synthesizer with Frequency 1.235 to 1.28 GHz, Step Size 100 KHz, Reference Frequency 10 MHz, Output Power 3 to 5 dBm, Harmonics -30 to -20 dBc. Tags: Surface Mount, PLL Frequency Synthesizer. More details for APL1257 can be seen below.