TH9876A - Regulated frequency generator - Google Patents

Abstract

The crystal-controlled frequency generation device of the stereo decoder for CMOS-based television receivers comprises three differential amplifiers: the first (50), the second (51a), and the third (51b), which produce an anti-phase output signal pair. The second and third differential amplifiers have variable receivers that change in the opposite manner to the frequency control signal 123a. The frequency signal of the crystal 124a is connected to the corresponding input terminals of the differential amplifiers. Thus, the phase of the signal developed at the input terminals of the differential amplifiers is shifted by approximately 90 degrees relative to the signals developed at the input terminals of the other two amplifiers. Three output signal pairs, 1501, 1502, 1515, 1516, 1528, 1529, are combined into a single-ended frequency signal which is then connected. The feedback loop is returned to the crystal to obtain a perfectly controlled feedback path, where the frequency of change is determined according to a frequency control contract.

Claims (4)

1. A controllable phase-shifting circuit for controlling the phase of the reference signal consists of 124 b, C1 devices for providing the first and second signals. Such first and second signals have a phase difference between them. First differential 50 responds to The first such signal is to produce the first 1501 output signal and the second 1502 anti-phase. The second differential amplifier 51 responds to The aforementioned second signal provides a controlled quantity of the third 1516 and the fourth 1515 anti-phase signals in response. It responds to 123 a received control signal, as below the third differential amplifier 52 is attached to the receiver. The second signal provides a controlled quantity of the fifth 1528 and the sixth 1529 anti-phase signals in response. Responding to the aforementioned control signals The first collection device MQ 3 for collecting the first 1501, the third 1516 and the fifth 1528 thereof to create. Signal, which is the first signal 56 a, the third signal and at These five have opposite phases and are characterized by The first collection device MQ4 for collecting the second signal 1502, the fourth 1515 and the sixth i 529 to generate the signal. This is the second signal 57 a, the fourth and the sixth signal. Will have opposite phases and The fourth amplifier MQ15 MQ16 MQ 17 MQ18 MQ19 responds to the aforementioned signal, which results in the aforementioned 56a and second 57a signals to form a controlled phase CK output. 2. The equipment set according to claim 1 has a special feature that is an expander. The second differential 51 and the third 52, which are arranged. Prepare the fourth signal 1515 and the sixth 1529. Such will be the character. Expanding a differential that can control the reception. 3. The equipment set according to claim 2 is characterized by the first and second gathering equipment. Dioc-connected transistor 4. The equipment set according to claim 3 has a special expansion that These four will be an illuminated differential expander. Form completed at once (4 claims, 2 pages, 4 pictures)