摘要:
An integrated circuit has an input connection for connecting an external signal conductor that passes signals to execute functions in the device. The external signal conductor can pick up strong interfering signals with high frequency content, for example when the device is used in a car. To protect against unintended execution of functions the device contains a timer circuit comprising a capacitance and a current supplying circuit coupled to an integration node. A discharge diode is coupled between the input connection and the integration node, with a polarity such that the discharge diode, when in forward bias, is capable of draining current from the current supplying circuit. A detector is coupled to the integration node for generating a signal to be supplied to the integrated circuit device to respond to a signal transition on the conductor. The diode serves to reset integration on the integration node before the detector detects the transition in case of short pulses. By using a diode instead of a switching transistor the circuit is more robust against the effect of interfering pulses.
摘要:
Line driver for a LIN-bus. The line driver has a current source output transistor (T1) for pulling down the LIN-bus wire (LB) to ground (GND). The LIN-bus wire (LB) is connected to a positive supply voltage (VBAT) through a pull-up resistor (R1). The output transistor (T1) is driven by a driver stage (DRV) in response to an input current (J1) at an input node (X). The driver stage has a further resistor (R2) connected between the gate of the output transistor (T1) and a reference terminal (GND), a reference transistor (T2) which has its source connected to the reference terminal (GND) and its drain coupled to the input node (X); the gates of the output transistor (T1) and the reference transistor (T2) are connected to an output (DAO1) of a differential amplifier (DA1) which has an inverting input (DAN1) coupled to a bias voltage source (E2) and a non-inverting input (DAP1) coupled to the input node (X). The further resistor (R2) stage provides a low-impedance path to ground for RF disturbances reaching the gate of the output transistor (T1) through the drain-gate capacitance of the output transistor (T1) and prevents these disturbances from penetrating the driver stage.
摘要:
Various exemplary embodiments relate a system for supplying power. The system may include a power source outputting a source voltage, a regulator connected to the power source, and an extension module connected to the power source. The regulator may output a first voltage when the source voltage is above a minimum threshold, and the extension module may output a second voltage when the source voltage falls below the minimum threshold.
摘要:
Various exemplary embodiments relate a system and method for supplying power. The system may include an input/output port, a regulator, and a clamp. The regulator may supply power to the input/output port in a first mode, sink current from the input/output port in a second mode, and be disabled in a third mode. The clamp may be disabled in the first and second modes, and may limit the voltage at the input/output port below a first value in the third mode.
摘要:
A system and method for driving a relay circuit involves driving a relay circuit using a first driver circuit if a voltage of a battery supply for the relay circuit is lower than a voltage threshold and driving the relay circuit using a second driver circuit if the voltage of the battery supply for the relay circuit is higher than the voltage threshold.
摘要:
A power supply circuit and a method for operating a power supply circuit involves selecting a normal operational mode or a pass-through operational mode for a switched mode power supply, in the normal operational mode, converting an input voltage of a power supply circuit to an intermediate voltage using a switching regulator of the switched mode power supply, in the pass-through operational mode, disabling the switching regulator such that the input voltage of the power supply circuit is unchanged by the switching regulator and an electric current consumption of the switching regulator approaches zero, and converting the intermediate voltage or the input voltage of the power supply circuit to an output voltage using a linear voltage regulator.
摘要:
An electronic circuit has a signal conductor (11), a power supply reference conductor (10) connected by a switching circuit. The switching circuit contains a PMOS transistor (17) and an NMOS transistor realized on a common substrate (100). The NMOS transistor (17) has a source coupled to the power supply reference conductor (10). The NMOS transistor (18) has a source coupled to the drain of the PMOS transistor (17), and a drain coupled to the signal conductor (11). A control circuit (13, 14, 15, 16) switches between an “on” state and an “off” state, in which the control circuit (13, 14, 15, 16) controls the gate source voltages of the first and second MOS transistor (17, 18) to make channels of these MOS transistors (17, 18) conductive and not to make the channels of these first and second transistors (17, 18) conductive respectively. Preferably a complementary switching circuit is also provided. The complementary switching circuit uses opposite polarity voltage differences, an NMOS transistor (27) coupled to a second power supply and a PMOS transistor (28) coupled to a signal conductor. The on resistances of the switching circuits are matched by matching the NMOS gate-source voltages, as well as the PMOS gate source voltages.
摘要:
Line driver for a LIN-bus. The line driver has a current source output transistor (T1) for pulling down the LIN-bus wire (LB) to ground (GND). The LIN-bus wire (LB) is connected to a positive supply voltage (VBAT) through a pull-up resistor (R1). The output transistor (T1) provides a ramp shaped output current under control of a ramp generator (RG). The ramp shaped output current in combination with the pull-up resistor (R1) asserts a ramp shaped output voltage on the LIN-bus wire (LB). According to the LIN-bus specifications the resistance of the pull-up resistor may vary between 500 Ohm and 1 kOhm. When the resistance is 1 kOhm, the output voltage is clamped to signal ground (GND) and a delay occurs between the edge in the data signal (TXD) and the corresponding rising ramp in the output voltage. This delay is reduced considerably by a comparator (CMP, T2) which monitors the output voltage and which increases the slew rate of the ramp generator (RG) when the output voltage is clamped and drops below a certain threshold.