MGP3006X6 View Datasheet(PDF) - Infineon Technologies

Part Name

Description

Manufacturer

MGP3006X6

GHz PLL with I2C Bus and Four Chip Addresses

Infineon Technologies 

MGP 3006X6

Circuit Description

Tuning Section

UHF/VHF The tuner signal is capacitively coupled at the UHF/VHF-input and

subsequently amplified.

REF

Q1, Q2

The reference input REF should be decoupled to ground using a capacitor

of low series inductance. The signal passes through an asynchronous

divider with a fixed ratio of P = 8, an adjustable divider with ratio N = 256

through 32767, and is then compared in a digital frequency/phase

detector to a reference frequency fREF = 7.8125 kHz.

This frequency is derived from a balanced, low-impedance 4-MHz crystal

oscillator (pin Q1, Q2) by dividing its output signal by Q = 512.

The phase detector has two outputs UP and DOWN that drive the two

current sources I+ and I– of a charge pump. If the negative edge of the

divided VCO-signal appears prior to the negative edge of the reference

signal, the I+ current source pulses for the duration of the phase

difference. In the reverse case the I– current source pulses.

PD, UD

If the two signals are in phase, the charge pump output (PD) goes into the

high-impedance state (PLL is locked). An active low-pass filter integrates

the current pulses to generate the tuning voltage for the VCO (internal

amplifier, external output transistor at UD and external RC-circuitry). The

charge pump output is also switched into the high-impedance state when

the control bit T0 = 1. Here it should be noted, however, that the tuning

voltage can alter over a long period in the high-impedance state as a

result of self-discharge in the peripheral circuitry. UD may be switched off

by the control bit OS to allow external adjustments.

By means of a control bit 5I the pump current can be switched between

two values by software. This programmability permits alteration of the

control response of the PLL in the locked-in state. In this way different

VCO-gains in the different TV-bands can be compensated, for example.

P0, P1, P2 The software-switched outputs P0, P1, P2 can be used for direct band

selection (20 mA current output).

P4, P7

P4 and P7 are general-purpose open-collector outputs. The test bit T1 = 1

switches the test signal Cy (divided input signal) to P7.

CAU

Four different chip addresses can be set by appropriate connection of pin

CAU.

Semiconductor Group

2

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