
DS21FT44/DS21FF44
107 of 117
AC CHARACTERISTICS—TRANSMIT SIDE
(VDD = 2.97 to 3.63V, TA = 0°C to +70°C for DS21FF44/DS21FT44
VDD = 2.97 to 3.63V, TA = -40°C to +85°C for DS21FF44N/DS21FT44N)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS
NOTES
TCLK Period
tCP
488
ns
TCLK Pulse Width
tCH
tCL
75
ns
TCLKI Pulse Width
tLH
tLL
75
ns
TSYSCLK Period
tSP
122
648
448
ns
1
2
TSYSCLK Pulse Width
tSH
tSL
50
ns
TSYNC or TSSYNC
Setup/Hold to TCLK or
TSYSCLK falling
tSU
tHD
20
tCH - 5
or
tSH - 5
ns
TSYNC or TSSYNC Pulse
Width
tPW
50
ns
TSER, TSIG, TLINK
Setup to TCLK,
TSYSCLK Falling
tSU
20
ns
TSER, TSIG, TLINK Hold
from TCLK, TSYSCLK
Falling
tHD
20
ns
TCLK or TSYSCLK Rise
and Fall Times
tR, tF
25
ns
Delay TCLK to TPOS,
TNEG Valid
tDD
50
ns
Delay TCLK to TCHBLK,
TCHCLK, TSYNC,
TLCLK
tD2
50
ns
Delay TSYSCLK to
TCHCLK, TCHBLK
tD3
75
ns
See Figures 23–11 to 23–13 for details.
NOTES:
1) TSYSCLK = 1.544MHz
2) TSYSCLK = 2.048MHz