mc44827 Freescale Semiconductor, Inc, mc44827 Datasheet - Page 7

• Manufacturer Part Number: mc44827
• Description: Low-power Tuning Circuit
• Manufacturer: Freescale Semiconductor, Inc

The Operational Amplifier
low input bias current and high power supply rejection. The
positive input is biased internally. The operational amplifier
needs 28.5 V supply (V CC2) as minimum voltage for a
guaranteed maximum tuning voltage of 28 V.
component values depend very much on the application
(tuner characteristic, reference frequency, etc.).
MOTOROLA ANALOG IC DEVICE DATA
“On”/“Off”
The operational amplifier is designed for very low noise,
Figure 8 shows a possible filter arrangement. The
NOTE: 1. 330 pF minimum is required for stability.
Figure 7. Equivalent Circuit of the Lock Output
Antenna
Filter
“Off”/“On”
5.0 k
AGC
UHF
B. P. Filter
VHF
100 k
200 A Typical
2.0 k
V TUN
B III
25 V Protection
Lock
V CC1 5.0 V
Oscillator
Mixer
Figure 8. Typical Tuner Application
F osc
MC44827/27B
IF
1.0 nF
5.0 V
(Note 1)
7
8
Gnd
9
330 p
MC44827/27B
The Oscillator
in series with a capacitor. The crystal operates in the series
resonance mode.
distortion.
Power Dissipation
200 mW (V TUN = 15 V with internal pull–up of 60 k , one
buffer “On” at 30 mA). It is calculated with the following
formula:
PD
)
The oscillator uses a 3.2 or a 4.0 MHz crystal tied to ground
The voltage at Pin 3 has low amplitude and low harmonic
The typical power dissipation of the circuit is about
Example: (5 x 23)
6
33 V
+
V
Pres
CC3
8
5
V
13
CC1
B3
18 nF
x I
12
CC3
)
B2
x I
120 k
8.2 nF
11
(0.15 x 30)
CC1
B1 B0
)
)
Program
10
Divider
4
Bus
Rec
V ref
32 – 15
)
V
sat(buffer)
60
External Switching
V
CC2
+
Phase
Comp
60 k
206.5
Ref Div
x 32
14 12 V
V CC3
Osc &
– V
x I
TUN
15
Lock
)
16
2
1
3
out(buffer)
(12 x 6.5)
x V
CL
DA
EN
12 pF
3.2/4.0 MHz
CC2
7