摘要:
In one embodiment, a method of forming a power supply controller may include configuring the power supply controller to control a pass transistor to form an output current responsively to a control signal and independently of the value of the output voltage until the control signal is less than a deviation from a desired value of the output voltage.
摘要:
In one embodiment, a reference generator forms a reference signal that may have temperature and process variations. A comparator that has similar variations is used to detect a signal using the reference.
摘要:
A circuit (10) having multiple poles within an active frequency range employs a movable zero (66) to maintain stability in the circuit (10) under variable load conditions. A pole (62) created by a frequency compensation element (14) maintains a fixed frequency within the active frequency range of the circuit (10). In addition, a variable load impedance (36) coupled to the circuit (10) generates a load pole (64) within the active frequency range of the circuit (10) that changes frequency over time. As the load pole (64) changes frequency, the frequency of the movable zero (66) is adjusted to achieve an enhanced stability condition within the circuit (10). In one embodiment, the frequency of the movable zero (66) tracks the frequency of the load pole (64) as the load impedance (36) changes.
摘要:
A regulator (200) has a pass transistor (250) for transferring a voltage from an input (202) to an output (205). A voltage sensor (231) at the output (205) carries a PTAT current (IA) A generator with diode or transistor chains (271, 272) derives a voltage VRES from serially coupled base-emitter path of transistors (381-386) having different current densities. The generator (271, 272) and a transistor pair (273) form a bandgap reference circuit. Each chain (271, 272) has transistors alternatively of a first type (pnp) and second type (npn). The value ratio (R4/R3) of resistances (240, 230) in the voltage sensor (231) can be chosen such, that the noise components of the voltage VOUT at the output (205) is low.
摘要:
A power switching circuit includes a power switching NPN transistor (1) having its collector electrode coupled to a reference potential terminal (17) and its emitter electrode coupled to an output terminal (7). A driver circuit (5) is provided having an input coupled to a supply terminal (6) and a driving current output coupled to the base electrode of the power transistor (1). A PNP transistor(4) has its emitter electrode coupled to the output terminal(7), its base electrode coupled to a reference voltage terminal (9) for receiving, in operation, a voltage which is positive relative to the reference potential and its collector electrode coupled to the base electrode of an NPN transistor (2). The NPN transistor (2) has its collector electrode coupled to the collector electrode of the power transistor (1) and its emitter electrode coupled to the base electrode of the power transistor (1).
摘要:
A low dropout (LDO) voltage regulator includes a voltage regulation loop for providing a gate drive signal to an output device, the gate drive signal proportional to an output current. The voltage regulation loop includes a current bias input for receiving a bias current. The LDO voltage regulator further includes a current bias control circuit for providing the adaptive bias current at a first value that is proportional to current limit value lab and the width-to-length ratio of transistors of the transconductance amplifier when the output current less than or equal to a threshold and increases the bias current from a threshold to a current limit value. The output current varies substantially linearly over a range of output current values between the threshold and the current limit value.
摘要:
In one embodiment, a voltage sense circuit receives an ac input signal and forms a rectified output voltage that is representative of the ac input signal.
摘要:
In one embodiment, a reference generator forms a reference signal that may have temperature and process variations. A comparator that has similar variations is used to detect a signal using the reference.
摘要:
In one embodiment, a voltage sense circuit receives an ac input signal and forms a rectified output voltage that is representative of the ac input signal.
摘要:
A band gap reference (32) provides low noise operation utilizing capacitor (98) to produce a low pass filter operating with high impedance node (104). Increased speed is realized using feedback signals at nodes (102) and (100) to control differential transistor pair (36, 42). A first current feedback stage using transistors (44, 50, 52 and 54) and a second current feedback stage using transistors (60, 62, 68, 70) is used to control current mirror stages which set the charge and discharge current at node (104). A first current mirror stage using transistors (64,76) comprise the current sink used to discharge capacitor (98) at node (104) and a second current mirror stage using transistors (58,74) comprise the current source used to charge capacitor (98) at node (104).