Kinetis KL24: 48MHz Cortex-M0+ Ultra-Low Power MCU, 64KB Flash, 8KB SRAM, Full-Speed USB, 48-QFN
Freescale
Freescale - MKL24Z32VFM4
Freescale - MKL24Z32VFT4
$3.32 - $7.47
Freescale - MKL24Z32VLH4
$3.41 - $3.53
Freescale - MKL24Z32VLK4
$4.57
Freescale - MKL24Z64VFM4
Freescale - MKL24Z64VLH4
$3.26 - $6.10