摘要:
Methods and apparatus to test electronic devices are disclosed. An example method includes setting a first controlled switch to prevent a current detect signal from tripping an overcurrent protection event controlling an operation of the device; setting a second controlled switch to route a first sensed voltage associated with the device to a voltage adjuster; sending a calibration current corresponding to a target threshold current through the device; detecting the first sensed voltage while the calibration current flows through the device; and setting a reference signal substantially equal to the first sensed voltage, wherein the reference signal is to be used to generate the current detect signal.
摘要:
Generally, with low drop out (LDO) regulators that use multiplexed power supplies, the transistors within the regulator can use a substantial amount of area. Here, a regulator is provided that uses a multiplexer to commonly control the back-gates of multiple power transistors within the LDO. By doing this, the area overhead that would normally be present with these switches (of the multiplexer) can be dramatically reduced without sacrificing performance.
摘要:
An output stage for an LED driver is provided. In particular, a low voltage clamp, which uses several cascode circuits, is provided to protect low voltage switching transistors in the range of two times higher voltage application under both normal and fault conditions. Additionally, a circuit for regulating the bias voltage applied to each of the cascode circuits is provided to prevent damage during startup, while an internal voltage regulator is settling.
摘要:
A circuit for independently controlling slew and propagation delay of a current DAC is provided. The circuit applies dual slope technique with feed-back control the gate (or control electrode) of a switching transistor to make propagation delay independent control from rise/fall slew rate. This allows one to adjust propagation delay and current slew rate separately to achieve better performance.
摘要:
An output stage for an LED driver is provided. In particular, a low voltage clamp, which uses several cascode circuits, is provided to protect low voltage switching transistors in the range of two times higher voltage application under both normal and fault conditions. Additionally, a circuit for regulating the bias voltage applied to each of the cascode circuits is provided to prevent damage during startup, while an internal voltage regulator is settling.
摘要:
Conventional circuits often have undesirable characteristics to due “hot spots” or use a large amount of area. Here, however, a charging circuit is provides that uses an improved driver. Namely, an amplifier within a current sensor is used to control the rate that a switch can charge an external capacitor. This is accomplished through the adjustment of the gain of the amplifier during a charging mode.
摘要:
A method for measuring for generating a touch capacitance measurement is provided. Gain and offset control signals are generated, where the gain and offset control signals are adjusted to compensate for base capacitance of a touch sensor. The gain control signal is applied to a touch sensor during a first phase of a clock signal, and the offset control signal is applied to an output circuit during a second phase of the clock signal. The output circuit is coupled to the touch sensor during the second phase of the clock signal. The touch capacitance measurement is generated by compensating for the base capacitance with the gain and offset control signals, and a gain is applied to the touch capacitance measurement.
摘要:
Conventional circuits often have undesirable characteristics to due “hot spots” or use a large amount of area. Here, however, a charging circuit is provides that uses an improved driver. Namely, an amplifier within a current sensor is used to control the rate that a switch can charge an external capacitor. This is accomplished through the adjustment of the gain of the amplifier during a charging mode.
摘要:
Methods and apparatus to test electronic devices are disclosed. An example method includes setting a first controlled switch to prevent a current detect signal from tripping an overcurrent protection event controlling an operation of the device; setting a second controlled switch to route a first sensed voltage associated with the device to a voltage adjuster; sending a calibration current corresponding to a target threshold current through the device; detecting the first sensed voltage while the calibration current flows through the device; and setting a reference signal substantially equal to the first sensed voltage, wherein the reference signal is to be used to generate the current detect signal.
摘要:
In a method and system for sensing current in a switching regulator (SWR) operating in a current mode, a power switch is coupled to receive the current from a switching element, the power switch being controlled by a gate signal. An inrush of the current causes an initial transient spike (ITS). A buffer having a buffer input and a buffer output is coupled to receive the gate signal and provide a buffered gate signal. The buffer output is disabled during the ITS. A sense switch (SW) is coupled to receive a portion of the current from the switching element, the SW being turned on by the buffered gate signal after the initial transient spike. A sense resistor (SR) is coupled to receive the portion of the current from the SW. An amplifier converts the portion of the current through the SR to a voltage signal for controlling the SWR.