Abstract: A single-rail switching regulator and method are provided. The switching regulator includes a split-rail reference generator coupled between a battery voltage (VBAT) and ground, and including a floating-rail generator to generate a floating-rail reference voltage (VSSHV_REF), a fixed-rail generator to generate a fixed-rail reference voltage (VDD_REF), a current-sinking (I-sink) buffer to receive VSSHV_REF and generate a floating-rail voltage on a floating-rail to power logic devices formed on an IC with the switching regulator, and a high-side switching transistor including a source and drain coupled between VBAT and ground, and a gate coupled to the floating-rail. The floating-rail reference generator is operable to generate a VSSHV_REF equal to VBAT?1.8V for VBAT between 1.8 and 4.8V, and 0V for VBAT less than 1.8V. The switching regulator further includes a low drop out regulator operable to receive VDD_REF and power digital devices formed on the IC using a fixed voltage.

Abstract: A floating-rail reference generator and method of operating the same are provided. Generally, the generator includes a tracking current source coupled in series with a current scaling resistor between an input voltage (VBAT) and ground. The tracking current source is operable to receive a reference voltage and couple a tracking current through the resistor to produce a floating-rail reference voltage (VSSHV_REF) at an output between the tracking current source and scaling resistor, wherein: VSSHV_REF=((VBAT-VGS)/k)·1/R·k·R, where VGS is a desired constant potential difference between VBAT and VSSHV_REF, k is a voltage scaling ratio, and R is a resistance of the current scaling resistor. In some embodiments, the tracking current source includes a transistor coupled between VBAT and the output, and controlled by a differential amplifier.

Abstract: A current-sink buffer is provided including a differential amplifier having a closed first-loop to provide a buffered output voltage, and a closed second-loop to sink transients in a load current of an output to ground. The first-loop includes a first transistor with a gate coupled to a reference-voltage, and a source coupled to a current-source; a second transistor with a gate coupled to a drain and the output, and a source coupled to the source of the first transistor; a first current-sink through which a drain of the first transistor is coupled to ground; and a second current-sink through which the second transistor drain is coupled to ground. The second-loop includes a third transistor with a grounded source, a drain coupled to the second transistor drain, and a gate coupled to the first transistor drain, and a capacitor coupled between the gate and drain of the third transistor.

Abstract: A floating-rail voltage generator and method are provided for use in a switched regulator. Generally, the generator includes a floating-rail reference generator, a current-sinking buffer and a current-sink. The reference generator is operable to generate a reference voltage (VSSHV_REF) equal to an input voltage (VBAT) minus 1.8 V for VBAT between 1.8V and 4.8V, and equal to 0V for VBAT less than 1.8V. The buffer is coupled between VBAT and ground, and operable to receive the VSSHV_REF and generate a continuous floating-rail voltage (VSSHV) on a floating-rail for VBAT between 1.6V and 4.8V. The current-sink is operable to receive VSSHV_REF and VSSHV, and to turn on a current sinking switch coupled between the floating-rail and ground by setting a set-reset latch having a latch output coupled to a gate of the current sinking switch when a transient load current signal is received from a load coupled to the floating-rail.

Abstract: Systems, methods, and devices provide sampling for data converters. Methods include receiving a voltage from a voltage source, and identifying transconductance parameters and resistance parameters associated with a data converter, the transconductance parameters identifying a transconductance of the data converter. Methods also include selecting a resistor from a plurality of dynamically selectable resistors based on the resistance parameters, generating, using a programmable gain amplifier, a current based, at least in part, on the selected resistor and the received voltage, and providing the current to the data converter.

Abstract: A current-sink and method of using the same is provided for sinking transient load currents of a load coupled to a floating-rail. In one embodiment, the current-sink includes a latch system operable to receive a transient load current signal from the load and set a latch to apply a voltage to a gate of a current sinking switch. The current sinking switch includes a first source/drain (S/D) coupled to the floating-rail, and a second S/D coupled to ground, and is operable to sink the transient load current to provide a stable floating-rail voltage (VSSHV) on the floating-rail. Generally, the latch system further includes a dynamically biased comparator for comparing VSSHV to a reference voltage and resetting the latch when a difference is less than a predetermined voltage. A dynamic bias circuit coupled to a latch output enables the comparator only while the transient load current is present.

Abstract: A low-dropout (LDO) regulator includes a voltage reference node and a one-stage differential amplifier coupled to the voltage reference node. The one-stage differential amplifier includes: a differential pair of NMOS transistors; a mirroring load comprising a first current source and a PMOS transistor; a direct feed-forward (DFF) loop formed by the PMOS transistor and its parasitic gate-to-drain capacitance during a load transient; and an indirect regulation feedback (IRF) loop formed by the differential pair of NMOS transistors, a resistor, and the PMOS transistor to provide direct current (DC) voltage regulation.