MC44S803EP FREESCALE [Freescale Semiconductor, Inc], MC44S803EP Datasheet - Page 17

• Manufacturer Part Number: MC44S803EP
• Description: Low Power CMOS Broadband Tuner
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Freescale Semiconductor
Table 20. 15 Bit N Counter Control Bits (N2)
Counter Value Functions (N2)
frequency and the N2 and R2 dividers as described in the
F
Where:
•
•
to Second IF Amplifier. This gain adjustment is not intended
for AGC control but as a way to easily adjust the gain
distribution within the tuner. Table 21 shows the affect of the
IF Amp Gain bits.
Amplifier 2 as shown in Table 22.
Detec
MSB
CLIF CLRF
VCO2
R16
tor
IF
The Second LO Frequency is a function of reference
0
Detector
The G7 and G6 bits give a limited amount of gain control
In a similar manner, G3 adjusts the gain of the Post
F
oscillator (VCO2)
N2: Value of control bits for 15 bit programmable N2
counter. (N2-2 is actually programmed into register)
N Counter
Clear
VCO2
32769
Value
4310
equation.
Detec
Table 21. IF Amp Gain
R15
2
*
*
RF
tor
0
: Output frequency of the second voltage controlled
IF Amp Gain
6.0 dB
12 dB
18 dB
20 dB
AGC
Amp
R14
LP5
IF
0
F
N14
VCO2
0
0
1
*
*
R13 R12
0
= N2 * F
N15
Power Adjust
Post
Amp
0
0
1
LP3 LPB2 LPB1 LPB0 S1 G7 G6
*
*
G7
0
2
0
0
1
1
N12
R11
0
1
1
*
*
OSC
0
G6
Mix1
0
1
0
1
N11
/ R2
R10
0
0
1
*
*
0
Reset State
Figure 16. Circuit Adjust Register Format
N10
Amp
0
0
1
Pre
*
*
R9
0
1
Out
N9
Sel
R8 R7 R6 R5 R4
0
0
1
*
*
1
IF Amp
1
Gain
N8
0
0
1
*
*
1
N7
0
1
1
*
*
1
•
•
•
CIRCUIT ADJUST REGISTER (CR-7)
adjustments to various circuits.
Table 23.
The Circuit Adjust Register provides gain and power
The G1 bit adjusts the gain of Pre Amplifier 1 as shown in
N6
1
F
oscillator. (Example: F
R2: Divide ratio of second programmable reference
counter.
F
F
Reference Dividers register)
0
1
1
*
*
OSC
REF2
REF2
Amp 2
Adjust
Gain
Post
: Output frequency of the reference frequency
G3
R3
N5
: Reference Frequency for Second LO.
1
0
0
1
*
*
= F
Table 22. Post Amp 2 Gain
Table 23. Pre Amp 1 Gain
Post Amp 2 Gain
Pre Amp 1 Gain
OSC
N4
R2
0
1
1
0
*
*
Nominal
+1.0 dB
6.0 dB
8.3 dB
/ R2. (R2-1 is actually programmed into
Amp 1
Adjust
Gain
Pre
N3
R1
G1
0
0
1
*
*
1
OSC
N2
R0 A3 A2 A1 A0
0
1
1
*
*
1
= 4.0 MHz)
G3
G1
0
1
0
1
0
N1
Address Bits
0
0
1
*
*
Reset State
Reset State
1
N0
0
0
1
*
*
1
LSB
1
Reset State
MC44S803
Reset
State
17