828L8B-2 Datasheet, PDF (2/19 Pages) Frequency Devices, Inc. – 2" x 2" 8-Pole Filters

828 Series
8-Bit Programmable Filters
Digital Tuning Characteristics
The digital tuning interface circuits are a parallel set of eight
(8) 4053 CMOS switches which accept CMOS compatible
inputs for the eight tuning bits (D₀ - D₇).
Filter tuning follows the tuning equation given below:
fc = ( fmax/256 ) [ 1 + D₇ x 2⁷ + D₆ x 2⁶ + D₅ x 2⁵ + D₄ x 2⁴ +
D₃ x 2³ + D₂ x 2² + D₁ x 2¹ + D₀ x 2⁰ ]
where D₁ - D₇ = "0" or "1", and
fmax = Maximum tuning frequency;
fc = corner frequency;
Minimum tunable frequency = fmax/256 (D₀ thru D₇ = 0);
Minimum frequency step (Resolution) = fmax/256
Data Input Specifications
Input Data Levels (CMOS Logic)
Input Voltage (Vs = 15 Vdc)
Low Level In
0 Vdc min.
High Level In
11 Vdc min.
4 Vdc max.
15 Vdc max.
Input Current
High Level In
Low Level In
- 10 ^-5 µA typ. -1 µA max..
+10 ^-5 µA typ. +1 µA max.
Input Capacitance
5 pF typ
7.5 pF max.
Input Data Format Frequency Select Bits
Positive Logic
Logic "1" = +Vs
Logic "0" = Gnd
Bit Weighting
D₀
D₇
Frequency Range
(Binary-Coded)
LSB (least significant bit)
MSB (most significant bit)
256 : 1, Binary Weighted
Digital Tuning &
Control Characteristics
Pin-Out Key
IN Analog Input Signal
OUT Analog Output Signal
GND Power and Signal Return
+Vs Supply Voltage, Positive
-Vs Supply Voltage, Negative
Os Offset Adjustment
OUT +Vs -Vs
D₇ Tuning Bit 7 (MSB)
D₆ Tuning Bit 6
D₅ Tuning Bit 5
D₄ Tuning Bit 4
D₃ Tuning Bit 3
D₂ Tuning Bit 2
D₁ Tuning Bit 1
D₀ Tuning Bit 0 (LSB)
2.00
IN Os ⁴
Bottom View
D₇
D₆
D₅
D₄
GND
D₃
D₂
D1
D₀
MSB --- --- --- --- --- --- LSB Bit
Weight
2⁷
2⁶
2⁵
2⁴
2³
2²
2¹
2⁰
fc
Corner
Frequency
D₇ D₆ D₅ D₄ D₃ D₂ D₁ D₀
0
0
0
0
0
0
0
0 fmax/256
0
0
0
0
0
0
0
1 fmax/128
0
0
0
0
0
0
1
1 fmax/64
0
0
0
0
0
1
1
1 fmax/32
0
0
0
0
1
1
1
1 fmax/16
0
0
0
1
1
1
1
1 fmax/8
0
0
1
1
1
1
1
1 fmax/4
0
1
1
1
1
1
1
1 fmax/2
1 1 1 1 1 1 1 1 fmax
2
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