Minimum life-span- The shortest Bhava (birth in a particular realm of mundane existence) which is equal to 256 Āvalikās (16777216 Āvalikās=48 minutes).
do ya sayā chappannā āvaliyāṇaṃ tu khuḍḍabhavamāṇaṃ.
...kṣullakabhavagrahaṇānyekasminnucchavāsaniḥśvāse sātirekāṇi saptadaśa mantavyāni; yat uktam- 'khuḍḍāgabhavaggahaṇā sattarasa havaṃti āṇupāṇammi'.
(ViBhā 3318 Vṛ)