TDA9884TS/V1,112 NXP Semiconductors, TDA9884TS/V1,112 Datasheet - Page 8

• Manufacturer Part Number: TDA9884TS/V1,112
• Description: IC IF-PLL I2C-BUS DEMOD 24-SSOP
• Manufacturer: NXP Semiconductors
• Type: Demodulatorr

Specifications of TDA9884TS/V1,112

• Package / Case: *
• Applications: Mobile Reception
• Mounting Type: Surface Mount
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: - 20 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 935270308112; TDA9884TS/V1; TDA9884TS/V1

Philips Semiconductors
TDA9884_2
Product data sheet
7.1 VIF amplifier
7.2 Tuner AGC and VIF-AGC
7.3 VIF-AGC detector
The VIF amplifier consists of three AC-coupled differential stages. Gain control is
performed by emitter degeneration. The total gain control range is typically 66 dB. The
differential input impedance is typically 2 k in parallel with 3 pF.
This block adapts the voltages, generated at the VIF-AGC and SIF-AGC detectors, to the
internal signal processing at the VIF and SIF amplifiers and performs the tuner AGC
control current generation. Normally it is derived from the VIF-AGC, for the true split sound
mode it is derived from the SIF-AGC. The onset of the tuner AGC control current
generation can be set either via the I
potentiometer at pin TOP (in case that the I
presence of a potentiometer is automatically detected and the I
Furthermore, derived from the AGC detector voltage, a comparator is used to test if the
corresponding VIF input voltage is higher than 200 V. This information can be read out
via the I
Gain control is performed by sync level detection (negative modulation) or peak white
detection (positive modulation).
For negative modulation, the sync level voltage is compared with a reference voltage
(nominal sync level) by a comparator which charges or discharges the integrated AGC
capacitor directly for the generation of the required VIF gain. With mobile mode the
currents are increased by a factor of approximately 8 for very fast reaction. By use of an
AGC event detector, the gain increase time constant (discharge current) additionally
reduces in with a too-low VIF signal.
For positive modulation, the white peak level voltage is compared with a reference voltage
(nominal white level) by a comparator which charges (fast) or discharges (slow) the
external AGC capacitor directly for the generation of the required VIF gain. The need of a
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FPLL detector
VCO and divider
AFC and digital acquisition help
Video demodulator and amplifier
Sound carrier trap
SIF amplifier
SIF-AGC detector
Single reference QSS mixer
AM demodulator
FM demodulator and acquisition help
Audio amplifier and mute time constant
Internal voltage stabilizer
I
2
C-bus transceiver and MAD
2
C-bus (bit VIFLEV = 1).
Rev. 02 — 12 May 2006
I
2
C-bus controlled multistandard alignment-free IF-PLL
2
C-bus (see
2
C-bus information cannot be stored). The
Table
16) or optionally by a
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
2
C-bus setting is disabled.
TDA9884
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