tda9898 NXP Semiconductors, tda9898 Datasheet - Page 16

• Manufacturer Part Number: tda9898
• Description: Multistandard Hybrid If Processing Semiconductors
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA9897_TDA9898_3
Product data sheet
8.4 DIF/SIF FM and AM sound AGC
8.5 Frequency phase-locked loop for VIF
8.6 DIF/SIF converter stage
Thus two switchable TAGC systems for negative/DIF and positive modulation
implemented.
L standard TAGC output changed from current output to voltage output, as it is not
necessary to adapt for other than 5 V tuner.
L standard tuner time constant switching integrated (= speed up function in the event of
step into high input levels), to minimize external application.
For high TOP accuracy at L standard, additional adjustment via optional potentiometer or
I
Tuner AGC status bit provided. This function enables TOP alignment without need for
TAGC voltage measurement (e.g. for TOP alignment in a complete set, where access to
internal signals is not possible).
External AGC control input for DIF. DIF includes 1st IF, zero IF and low IF.
Integrated gain control loop for SIF.
Bandwidth of AGC control for FM SIF related to used SAW bandwidth.
Peak AGC control in the event of FM SIF.
Ultra fast SIF AGC time constant when VIF AGC set to ultra fast mode.
Slow average AGC control in the event of AM sound.
AM sound AGC related to AM sound carrier level.
Fast AM sound AGC in the event of fast VIF AGC (speed up).
SIF AGC DC voltage monitor output with expanded internal characteristic.
Basic function as previous TDA9887 design.
PLL gating mode for positive and negative modulation, optional.
PLL optimized for either overmodulation or strong multipath.
Frequency conversion with sideband suppression.
Selection mode of upper or lower sideband for pass or suppression.
Suppression around zero for frequency conversion.
I/Q output mode for zero IF conversion.
Conversion mode selection via synthesizer for DIF and radio mode or via VIF Frequency
Phase-Locked Loop (FPLL) for TV QSS sound (FM/AM).
2
C-bus is provided.
Rev. 03 — 11 January 2008
TDA9897; TDA9898
Multistandard hybrid IF processing
© NXP B.V. 2008. All rights reserved.
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