DP8473N NSC [National Semiconductor], DP8473N Datasheet - Page 22

• Manufacturer Part Number: DP8473N
• Description: DP8473 Floppy Disk Controller PLUS-2
• Manufacturer: NSC [National Semiconductor]

Phase Locked Loop Characteristics
Note Measurements made with a repeating ‘DB6’’ data pattern with reverse write precompensation using recommended filter values for the configuration shown
in Figure 4c 25 C 5 0V 0% MSV
Note 5 The VCO gain is measured at the 1 0 Mb s data rate by forcing the data period over a range from 900 ns to 1100 ns and measuring the resulting voltage
on the filter pin The best straight line gain is fit to the measured points
Note 6 This is the current gain of the charge pump which is defined as the output current divided by the current through R
Note 7 This is the product of V
The K
resultant K
Note 8 The DP8473 is guaranteed to correctly decode a single shifted clock pulse at the end of a long series of non-shifted preamble bits as long as the single
shifted pulse is shifted less than the amount specified in T
in Table II
V
K
R
K
K
K
T
T
Symbol
SW
DW
REF
VCO
P(UP)
P(DWN)
PLL
1
VCO
portion of this specification is measured at the 1 0 Mb s data rate by forcing the data period over a range of 900 ns to 1100 ns and measuring the
VCO
K
P
is measured by forcing the Filter pin to 2 1V and measuring the ratio of the charge pump current over the input current
SETCUR Pin Reference
Voltage
VCO Gain (Note 5)
Recommended Pump
Resistor Range
Charge Pump Up Current
Gain (I
Charge Pump Down Current
Gain (I
Internal Phase Locked Loop
Gain (Note 7)
Static Window
(Note 8)
Dynamic Window
Margin
REF
REF
REF c
Parameter
I
I
P(UP)
P(DWN)
K
P c
K
) (Note 6)
VCO
) (Note 6)
The total variation in this specification indicates the total loop gain variation contributed by the internal circuitry
SW
The length of the preamble is long enough for the PLL to lock The filter components used are those
R
t
R
R
(R
Pump Up
Pump Down
(R
(Note)
DATA
1
1
1
1
1
250 kb s
500 kb s
1 0 Mb s
e
e
e
e
e
V
5 6 k
5 6 k
5 6 k
Conditions
e
CC
5 6 k )
5 6 k )
22
1 s
e
5V
V
g
CC
g
10%
10% F
e
5V
XTAL
e
Early
1075
24 MHz unless otherwise specified
530
259
3–12
2 50
2 25
Typ
1 1
25
75
70
70
1
Late
872
440
234
Mrad s V
(none)
(none)
Units
Mrad
Mrad
k
ns
ns
ns
%
V