Texas Instruments Corporation

Texas Instruments Incorporated Deutschland, Gmbh

Matthias Arnold

Johannes Gerber

Asif Qaiyum

Frank Dornseifer

Gabriel Alfonso Ricon-Mora

Ruediger Kuhn

Ronald Nerlich

Aymen Landoulsi

Korbinian Huber

Bernhard Ruck

Ralph Ledwa

Volker Rzehak

Frank Vanselow

Christian Sichert

Adi Baumann

Gabriel Alfonso Rincon-Mora

An integrated circuit is provided with a bandgap voltage reference circuit having a bandgap reference voltage output. A bandgap failure detection circuit is coupled to the bandgap reference voltage output. The bandgap failure detection forms a model value of the reference voltage from a first time, compares a present value of the reference voltage at a second time to the model value; and asserts a bandgap fail signal to indicate when the present value is less than the model value by a threshold value. The integrated circuit is reset by the bandgap fail signal. The detection circuit may be operated from a failsafe voltage domain that also allows a critical circuit to complete a pending operation during a reset.

Bandgap reference voltage failure detection

A proportional to absolute temperature (PTAT) generator, for example, generates a PTAT current (IPTAT) and a VBE (voltage base-to-emitter) in a first regulation loop. A voltage-to-current converter is operable to generate a complementary to absolute temperature current (ICTAT). The IPTAT and ICTAT are summed to obtain a zero temperature coefficient current (IZTC). One ICTAT and one resistor are used to generate the IZTC signal.

Low voltage current mode bandgap circuit and method

A proportional to absolute temperature (PTAT) generator generates a current PTAT (IPTAT) and a fractional VBE in a first regulation loop. A level shifting voltage-to-current converter is arranged as a second regulation loop and is operable to generate a current ZTC (IZTC) and/or a voltage ZTC (VZTC). Both regulation loops are nested into each other. In an embodiment, the voltage-to-current converter is operable to sum a scaled voltage PTAT (VPTAT/Y) with the fractional VBE (VBE/X) to generate the ZTC signal. In another embodiment, the voltage-to-current converter is operable to sum a delta voltage threshold (&#x394;VTH) with the fractional VBE (VBE/X) to generate the ZTC signal.

A start-up circuit for a reference circuit such as a bandgap reference circuit. The start-up circuit includes a diode-connected metal-oxide-semiconductor (MOS) transistor connected between a power supply node and a start-up node that is connected in turn to the gate of a current control MOS transistor in the reference circuit. The diode-connected MOS transistor and the current control MOS transistor are matched with one another. To start up the reference circuit, current is conducted through the diode-connected MOS transistor to set the gate voltage of the current control transistor at a threshold voltage below the power supply voltage. Current conducted by the current control transistor initiates operation of the bandgap reference circuit, and disables the start-up circuit.

Startup circuit for reference circuits

A bandgap reference circuit with curvature compensation. The circuit includes a first current mirror that mirrors the current conducted by the bandgap reference. A difference between the gate-to-source voltages in the two legs provides a first mirrored current with non-linear temperature stability. This first mirrored current is again mirrored by a second current mirror in which the mirror transistors also have differing gate-to-source voltages, with the current from this second current mirror coupled to the bandgap reference to compensate for curvature in the CTAT current over temperature.

Bandgap reference circuit with curvature compensation

An electronic device that includes a power on reset, a variable power supply filter coupled to the power on reset, and control logic coupled to the power on reset and the variable power supply filter. The control logic is configured to activate the variable power supply filter based on a core domain of the electronic device being active.

Adaptive system controlled power supply transient filter

The invention relates to an electronic device with a bandgap reference generator including a first path with series connection of a first bipolar transistor, a first resistor and a second resistor, and a second path with series connection of a second bipolar transistor and a third resistor. The first and second paths are supplied current via a common node through a fourth resistor controlled by an amplifier sensing voltage drops within the first and second paths. A curvature compensation stage compensates for a variation of base emitter voltage of the bipolar transistors by drawing a compensation current from the common resistor node.

Electronic device and method for generating a curvature compensated bandgap reference voltage

A mixed signal approach is applied to detect an output voltage condition as applied to a load. A current mode monitoring approach can be adopted and applied in discrete time using a mixed analog and digital approach. For application to various low drop-out voltage regulator situations, a sensing transistor can be connected in parallel with a feedback loop transistor of the low drop-out voltage regulator circuit to create a sensing current that is proportional to the current passing through the feedback loop transistor and thus the output current provided to the load. This sensing approach can be adapted to sense both overload and light load conditions to allow dynamic power control of the device.

Control for voltage regulators

A bandgap reference (BGR) startup verification circuit includes a current minor for receiving an output current from a bandgap reference (BGR) circuit and generating output currents therefrom. A first verification sub-circuit is coupled to receive a first output current to generate a detection voltage (Vdet) and includes a voltage comparator receiving Vdet and a voltage output of the BGR circuit (VBG) to provide a first verification output. A second verification sub-circuit including a voltage comparator is coupled to receive a second output current and a second reference current and provide a second verification output. A third verification sub-circuit includes a current comparator coupled to receive a third output current and a third reference current and provide a third verification output. A digital state machine has inputs receiving the first, second and third verification output, and circuitry for processing these outputs to determine whether the BGR circuit has properly started.

Verification of bandgap reference startup

The invention is an electronic device including a ferroelectric random access memory (FRAM), a first supply voltage domain, a second supply voltage domain and a low drop output voltage regulator (LDO) receive a first supply voltage of the first supply voltage domain and providing a second supply voltage of the second supply voltage domain. The second supply voltage domain supplies the FRAM. The LDO switches between a first state providing and maintaining the second supply voltage of the second supply voltage domain and a second state providing a high impedance output to the second supply voltage domain. The electronic device switches the LDO from the first state to the second state in response to a failure of the first supply voltage domain.

Electronic device and method for FRAM power supply management

The invention relates to a low leakage switch having an input node for receiving an input voltage and an output node for providing an output voltage. The low leakage switch comprises a main sampling transistor the backgate voltage of which is biased through other transistors, and wherein the control gate of the main sampling transistor is controlled through a second control signal and the control gates of the other transistors are controlled through a first control signal, wherein the electronic device is further configured to activate the other transistor for adjusting the backgate voltage of the main sampling transistor through the first control signal before activating the main sampling transistor for sampling the input voltage on a main sampling capacitor through the second control signal.

Electronic device and method for low leakage switching

An electronic device includes an integrated circuit with a FRAM memory and an integrated capacitor connected between a power supply for the FRAM memory and ground. The integrated capacitor has a capacitance sufficient to store the charge necessary for a complete read-and-write-back cycle of the FRAM memory. When granting read-access to the FRAM memory, the FRAM memory is supplied by the integrated capacitor which is then disconnected from the integrated circuit power supply. Upon receiving a request for a read-access to the FRAM memory, a charge detector detects whether the internal capacitor is sufficiently charged for a complete read-and-write-back cycle of the FRAM memory. Read-access to the FRAM memory is only granted if the internal capacitor is sufficiently charged and disconnected from the power supply. An alternative embodiment alternately charges and powers the FRAM from two integrated capacitors.

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Freising, Germany

Matthias Arnold