T4260-ILSH Atmel, T4260-ILSH Datasheet - Page 29

• Manufacturer Part Number: T4260-ILSH
• Description: IC AM/FM FRONT END W/PLL 44SSOP
• Manufacturer: Atmel

Specifications of T4260-ILSH

• Frequency: AM, FM
• Modulation Or Protocol: AM, FM
• Applications: AM/FM Radio Receiver
• Current - Receiving: 85mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 8 V ~ 10 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-SSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Sensitivity: -
• Memory Size: -
• Data Rate - Maximum: -

11.7
4528N–AUDR–11/09
External Voltage at AMLF (Pin 17)
Table 11-1.
Note:
The N- and R- divider can be calculated as following:
Example of AM settings:
If the receiving frequency is 0.84 MHz (AM) and the following conditions are:
f
a R-Divider of 400 is necessary.
R = f
N = AM Prescaler
By using two ICs, for example, it is possible to operate the AMLF (pin 17) of the second IC either
with the tuning voltage (VTUNE [pin 18]), the DAC 1 voltage [pin 1] or the DAC 2 voltage [pin 2]
from the first T4260. For voltage reduction at the AMLF [pin 17], a voltage factor ratio of 100/16
(R
This means that an applied voltage from 0.5 V at pin 17 (AMLF) corresponds to a tuning voltage
of 3.625V. It is recommended to use R
is 10 k to 1 M and 1.6 k to 160 k for R
N = AM Prescaler
N = (f
R = f
f
f
ref
VCO
ref
1
= 4 MHz; f
/R
= reference oscillator frequency (pin 27)
ref
= N
ref
2
Divider (AM Prescaler)
rec
) is required.
/f
/f
step
The AM Prescaler Divider Settings with f
tuning range depends on the tuning diode and the inductor in the VCO circuit. The tank of the
VCO should be designed for a maximum range at pin 18 (VTUNE) of 1.5 V to VSPLL - 1 V for a
good S/N performance.
step
+ f
Divide by 10
IF
= 4 MHz/10 KHz = 400
Divide by 2
Divide by 3
Divide by 4
Divide by 5
Divide by 6
Divide by 7
Divide by 8
Divide by 9
f
No divider
step
)/f
step
AM Prescaler (Divider) Settings and the Reception Frequencies
step
= 10 kHz; f
(f
(f
rec
rec
+ f
+ f
IF
IF
IF
)/f
)/f
= 10.7 MHz and an AM-Prescaler of 10 a N-Divider of 11540 and
step
step
= 10
1
Minimum Reception
with 100 k and R
Frequency [MHz]
(0.84 MHz + 10.7 MHz)/10 KHz = 11540
2
.
VCO
22.033
13.85
5.667
3.329
1.575
0.211
(AM mode)
(FM mode)
(For all modes)
87.5
38.4
8.94
from 98.2 MHz to 124 MHz is only an example. The
0
2
with 16 k . The allowed range of R
Maximum Reception
Frequency [MHz]
30.633
113.3
9.967
7.014
3.078
51.3
20.3
14.1
4.8
1.7
T4260
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