
PC-TEL, Inc.
56
1789N0DOCDAT01A-0399
PCT1789N DATA SHEET
S
WITCHING
C
HARACTERISTICS
!
PRELIMINARY
PRELIMINARY
Serial Interface (DCE = 0)
Given values are: V
A
= charge pump, V
D
= 3.0 V to 5.25 V; T
A
= 0 °C to 70 °C for K-grade, –40 °C to +85 °C for
B-grade; C
L
= 20 pF.
All timing is referenced to the 50% level of the waveform. Input test levels are: V
IH
= V
D
– 0.4V, V
IL
= 0.4V.
Table 24 Switching Characteristics—Serial Interface (DCE = 0)
Figure 19 Serial Interface Timing Diagram (DCE = 0)
Parameter
Cycle time, SCLK
Symbol
t
c
t
dty
t
d1
t
d2
t
d3
t
su
t
h
t
sfc
t
hfc
Min
354
Typ
Max
Unit
ns
1/256 Fs
SCLK duty cycle
50
%
Delay time, SCLK
↑
to FSYNC
↓
Delay time, SCLK
↑
to SDO valid
Delay time, SCLK
↑
to FSYNC
↑
Setup time, SDI before SCLK
↓
Hold time, SDI after SCLK
↓
Setup time, FC
↑
before SCLK
↑
Hold time, FC
↑
after SCLK
↑
–10
20
ns
20
ns
–10
20
ns
25
ns
20
ns
40
ns
40
ns
SCLK
V
OH
V
OL
D15
D14
D1
D0
16-bit
SDO
D15
D14
D1
D0
16-bit
SDI
t
d2
t
su
t
h
FSYNC
(mode 1)
t
d3
t
c
t
hfc
t
sfc
FC
FSYNC
(mode 0)
t
d1
t
d3