Abstract: A low-noise wide band preamplifier (10) provides an output voltage signal (V.sub.O) corresponding to the variation in resistance of a sensor such as Magneto-resistive (MR) head (4) which is used to read the data stored on a magnetic media. In this preamplifier, a transistor (12) and resistor (13) combination is used to function as a transimpedance amplifier (11) to increase the frequency bandwidth of the preamplifier and reduce the noise. The transimpedance amplifier (11) takes its input from an input transistor (3) coupled between the MR head (4) and a current source (2). A biasing circuit formed by a transconductance amplifier (12) and a capacitor (5) is used to control the input transistor (3) so that the average current passing through the input transistor (3) matches the current provided by the current source (2).

Abstract: A control circuit (100) which receives horizontal synchronising pulses (265) and generates a horizontal drive output signal (455) for a cathode ray tube (CRT) display. The horizontal control circuit (100) generates two ramp signals. A first ramp signal (410) for horizontal position adjustment of an image on the CRT display, and a second ramp signal (440) for propagation delay compensation of a deflection circuit (155) coupled to the CRT display. The control circuit (100) also provides digital of control of the duty cycle of the horizontal drive signal (455).

Abstract: A gain control signal (VCTRL) is provided to a temperature compensating circuit (12) which produces a differential temperature compensating gain control signal (VDT). A gain compensating circuit (14) receives the differential temperature compensating gain control signal (VDT) and provides a differential gain and temperature compensating gain control signal (VDTG) to an amplifier (16). The differential gain and temperature compensating gain control signal (VDTG) varies the gain of the amplifier (16) to be substantially linear with respect to variation of the gain control signal (VCTRL) and to compensate for variation in temperature.

Abstract: An improved vertical sync separator for a TV receiver includes an integrator circuit that comprises a current mirror one current path coupled to a normally conducting semiconductor element to discharge a capacitor and another current path coupled to a signal receiving semiconductor element to charge the capacitor. The output of the integrator circuit is coupled to an amplifier having a slicing level that varies with the strength of the received signal.