TEA5777HN-T NXP Semiconductors, TEA5777HN-T Datasheet - Page 41

• Manufacturer Part Number: TEA5777HN-T
• Description: Tuners AM/FM STEREO
• Manufacturer: NXP Semiconductors

Specifications of TEA5777HN-T

• Bus Type: I2C, 3-Wire
• Maximum Frequency: 2.047 MHz, 409.55 MHz
• Minimum Frequency: 0.512 MHz, 51.2 MHz
• Modulation Technique: AM, FM
• Mounting Style: SMD/SMT
• Package / Case: HVQFN-48
• Function: Radio
• Operating Supply Voltage: 3 V
• Supply Voltage (min): 2.7 V
• Supply Voltage (max): 7 V
• Minimum Operating Temperature: - 10 C
• Maximum Operating Temperature: + 65 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: TEA5777HN/N2,518

Philips Semiconductors
13. Application information
TEA5777_1
Product data sheet
13.1.1 AM coil requirements
13.1.2 AM coil alignment
13.1 AM coil requirements and alignment
The AM receiver is a magnetic field receiver. It can be used with a ferroceptor or an
antenna. In both cases, the antenna can be seen as an inductor that should be in
resonance with the on-chip C-bank at the frequency of interest. The C-bank values are
such that a nominal device and nominal antenna inductor value result in the correct tuning
grid depending upon bit STEP0; see
nominal value and tuning range of the AM antenna. Due to spread an alignment is
needed.
In order to align the antenna C-bank the antenna coil must meet the requirements of
Table
Table 47.
[1]
Alignment is setting the right C-align value and tuning the AM coil. This is done as follows:
The f
This procedure only has to be done once in order to fit the AM coil and device together.
The C-align data has to be stored in the microcontroller and should be written every time
the device is powered up.
For C-align the internal digital controlled capacitor is used in principle. It is also possible to
use an external trim capacitor (0 pF to 17 pF) instead. This has the advantage that no
alignment data has to be stored in the microcontroller at the cost of one trim capacitor.
Parameter
Nominal value
Tuning range needed for alignment
(excluding own tolerance)
Optimal TC1
1. Set C-align = 0
2. Measure the resonance frequency 1 (f
3. Measure the resonance frequency 2 (f
4. Set C-bank = 0:
Optimal means that the LC product (L of AM coil and C of C-bank) has zero TC1, since
TC1(C-bank) = +50 ppm/K. Having TC1(L of AM coil) equal to 50 ppm/K is not a hard requirement.
However, it is advisable to keep the TC1(LC product) < 350 ppm/K.
– Tune C-align until the resonance frequency 3 becomes f
– Tune AM coil until the resonance frequency 4 becomes f
rsn3
47.
and f
AM coil requirements
[1]
rsn4
values can be calculated based upon f
Rev. 01 — 11 April 2006
Low-power AM/FM stereo radio for handheld applications
Table 16
Value
203 H
50 ppm/K
16 %
rsn1
rsn2
) with C-bank = 0
) with C-bank = 122
and
Table
27.This puts requirements on the
rsn1
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
and f
rsn3
rsn4
rsn2
.
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