CS61884
DS485F3 59
19.7 Master Clock Switching Characteristics
19.8 Transmit Switching Characteristics
19.9 Receive Switching Characteristics
* All parameters guaranteed by production, characterization or design.
Notes: 20. Output load capacitance = 50pF.
21. MCLK is not active.
22. Parameters guaranteed by design and characterization.
Parameter Symbol Min. Typ Max Units
MASTER CLOCK (MCLK)
Master Clock Frequency E1 Modes MCLK 2.048 MHz
Master Clock Frequency T1/J1 Modes MCLK 1.544 MHz
Master Clock Tolerance - -100 +100 ppm
Master Clock Duty Cycle - 40 50 60 %
Parameter Symbol Min. Typ Max Units
E1 TCLK Frequency 1/t
pw2
-2.048- MHz
E1 TPOS/TNEG Pulse Width (RZ Mode) 236 244 252 nS
T1/J1 TCLK Frequency 1/t
pw2
-1.544- MHz
TCLK Tolerance (NRZ Mode) -50 - 50 PPM
TCLK Duty Cycle t
pwh2
/t
pw2
--90%
TCLK Pulse Width 20 - - nS
TCLK Burst Rate Note 22 --20MHz
TPOS/TNEG to TCLK Falling Setup Time (NRZ Mode) t
su2
25 - - nS
TCLK Falling to TPOS/TNEG Hold time (NRZ Mode) t
h2
25 - - nS
TXOE Asserted Low to TX Driver HIGH-Z - - 1 μS
TCLK Held Low to Driver HIGH-Z Note 21 81220μS
Parameter Symbol Min. Typ Max Units
RCLK Duty Cycle 40 50 60 %
E1 RCLK Pulse Width 196 244 328 nS
E1 RPOS/RNEG Pulse Width (RZ Mode 200 244 300 nS
E1 RPOS/RNEG to RCLK rising setup time t
su
150 244 - nS
E1 RPOS/RNEG to RCLK hold time t
h
200 244 - nS
T1/J1 RCLK Pulse Width 259 324 388 nS
T1/J1 RPOS/RNEG Pulse Width (RZ Mode) 250 324 400 nS
T1/J1 POS/RNEG to RCLK rising setup time t
su
150 324 - nS
T1/J1 RPOS/RNEG to RCLK hold time t
h
200 324 - nS
RPOS/RNEG Output to RCLK Output (RZ Mode) - - 10 nS
Rise/Fall Time, RPOS, RNEG, RCLK, LOS outputs t
r
, t
f
- - 85 nS
