SSI32F8030 Datasheet, PDF (8/10 Pages) List of Unclassifed Manufacturers – Programmable Electronic Filter

SSI 32F8030
Programmable
Electronic Filter
SUM
LP
HP
ƒc
Control
IFP
VR
LP
HP
Boost
Control
VBP
32F8030
to µController
Rx
IR
Ref
Cx DACF
VR3
7-bit
DAC
Ref
DACS
7-bit
DAC
Serial Control
Phase
Lock
Loop
7-bit
DAC
7-bit
DAC
FOUT
To Data Sync
DACI
To Data Sync
DACM
To Data Sync
32D4661
2k
IN+
IN–
BYP
Charge
Pump
FWR
Active
Differentiator
DFF
RD
OS
To Data Sync
AGC
LEVEL
HYS
32P54X
IOF = DACF output current
IOF = (0.98F•VR)/127Rx
Rx = (0.98F•VR)/127IOF
Rx = current reference setting resistor
VR = Voltage Reference = 2.2V
F = DAC setting: 0-127
Full scale, F = 127
For range of Max ƒc = 2.5 MHz then IFP = 0.8 mA
Therefore, for Max programming current range to 0.8 mA:
Rx = (0.98)(2.2/0.8) = 2.7 kΩ
Please note that in setups such as this where IFP is used for cutoff frequency programming VFP must be left open.
FIGURE 2: Applications Setup, Constant Density Recording
32F8030, 32P54X, 32D4661
INPUT
+1.31703
S ²+ S 1.68495 + 1.31703
+
∑
+
2.95139
S ²+ S 1.54203 + 2.95139
5.37034
S ²+ S 1.14558 + 5.37034
NO0R.8M6133
S + 0.86133
–KS ²
S ²+ S 1.68495 + 1.31703
S
Normalized for ωc = (2π) ƒc = 1
S + 0.86133
AN and AD are adjusted for unity gain (0 dB) at F = 0.67 ƒc
Denormalize the frequency by substituting S ¡ (S/2πƒc)
Eq for ƒc = 2.5 MHz, S = S / [(2π) (2.5 • 10 ⁶)] = S / (1.57080 • 10 ⁷)
NORM
AN
DIFF
AD
FIGURE 3: 32F8030 Normalized Block Diagram
8