Freescale Semiconductor,inc.

Kulbhushan Misri

Sanjay Kumar Wadhwa

Qadeer Ahmad Khan

Divya Tripathi

Chetan Verma

Amit Roy

Vijay Tayal

Amit Kumar Dey

Siddhartha Gk

Deeya Muhury

Himanshu Mangal

Ashis Maitra

Harkaran Singh

Gopal Krishna Siddhartha

Venkataramana Pandiri

Murugesan Raman

A method of physical design of an IC using an EDA tool includes identifying elements of the IC design that have excess positive timing slack. The excess timing slack elements are placed in a separate partition and then parameters of the characteristics of the excess timing slack elements are modified to reduce their excess timing slack, such as reducing the voltage supplied to the separate partition, thereby lowering power consumption of the IC design.

System for partitioning integrated circuit design based on timing slack

A level shifter operates using first and second input signals. When the first and second input signals are in respective first and second states, a first switching element is activated and an output node is pulled toward a first voltage, first pull-down protection and first pull-down switching elements are deactivated, a first protection node is connected to a first bias voltage, second pull-down protection and second pull-down switching elements are activated, and a second protection node is pulled to a second voltage. When the first and second input signals are in respective second and first states, the first switching element is deactivated, the first pull-down protection and first pull-down switching elements are activated, the output node and the first protection node are pulled toward the second voltage, the second pull-down protection and second pull-down switching elements are deactivated, and the second protection node is connected to the first bias voltage.

High-speed level shifter with voltage swing protection

A clock signal generator provides a gated clock signal GCLK to trigger operation of dual-edge triggered circuits. A first detector generates, while a clock gating signal /EN is asserted, a first detector output signal that is asserted or de-asserted as a function of disjunction or conjunction respectively of the values that an input clock signal CLK and the gated clock signal GCLK had when the clock gating signal /EN transitioned. A second detector generates, while the clock gating signal /EN is de-asserted, as the value of the gated clock signal GCLK, the value CLK or its complement /CLK as a function of the first detector output signal. When the clock gating signal /EN is asserted, the second detector maintains the value that the gated clock signal GCLK had when the clock gating signal /EN transitioned from de-asserted to asserted.

Dual-edge gated clock signal generator

Forward bulk biasing circuitry for PMOS and NMOS transistors is provided. The bulk biasing circuitry includes two N-type MOS transistors, two P-type MOS transistors, and two capacitors. The forward bias to a bulk terminal of a transistor increases a threshold voltage of a transistor, thereby reducing a transition time and improving the performance of the transistor. The forward bias is provided only when the transistor transitions from one state to another, thereby reducing leakage power dissipation during active and standby modes of an integrated circuit that includes the transistor.

MOS transistor with forward bulk-biasing circuit

An apparatus for protecting a device against an over-voltage condition that is in excess of its breakdown voltage includes a detector for detecting the over-voltage condition and a protection circuit for protecting the device in response to detection of the over-voltage condition. The protection circuit may include a transmission gate and a PMOS transistor for producing a protection signal. The protection signal may be applied to a gate and/or a drain and/or a source and/or a well of the device such that a voltage across the device does not exceed the breakdown voltage. The protection signal may be derived from the over-voltage condition independent of whether a supply of power to the device is present.

Short circuit and over-voltage protection for a data bus

A compensation circuit and a method that compensates for process, voltage and temperature (PVT) variations in an integrated circuit that includes functional modules. The compensation circuit includes a signal generator, a first code generator, a second code generator, and a mapping module. The signal generator generates a first signal and a second signal depending on aligned process corner, voltage and temperature variations and skewed process corner variations respectively. The first code generator receives the first signal, and generates a first calibration code. The second code generator receives the second signal, and generates a second calibration code. The mapping module provides the first and second calibration codes for compensating for the aligned process corner, voltage and temperature variations and the skewed process corner variations associated with the functional modules respectively.

PVT variation detection and compensation circuit

A compensation circuit and a method for detecting and compensating for process, voltage, and temperature (PVT) variations in an integrated circuit. The integrated circuit includes plural logic modules that include PMOS transistors and NMOS transistors. The compensation circuit includes first and second functional modules, which generate first and second calibration signals. The first and the second calibration signals are used to compensate for the PVT variations in PMOS and NMOS transistors.

A compensation circuit and a method for compensating for process, voltage and temperature (PVT) variations in an integrated circuit (IC). The IC includes several functional modules, each of which includes a set of functional units, and generates an output signal in response to an input signal. The compensation circuit includes a code generator and a logic module. The code generator generates a digital code for each functional unit. The digital codes are based on phase differences between the input signal and the output signal. The logic module generates calibration codes based on the digital codes. The calibration codes compensate for the PVT variations in the corresponding functional units.

A transmission line driver with slew rate control includes high and low side ramp generators for generating charge and discharge ramp signals, respectively, which are input to respective comparators and a pair of source follower transistors. A pair of additional transistors is connected to the pair of source follower transistors and a pair of staggered drivers is connected to the pair of additional transistors.

Transmission line driver

A digital clock frequency doubler for increasing an input frequency of an input clock signal includes an input block, and a generator block. The input block receives the input clock signal, and generates a pulse signal having an ON period equal to the input clock signal period. The generator block is coupled to the input block. The generator block receives the pulse signal and divides a period of the pulse signal by a period of a high frequency digital signal and then generates an output clock signal with an output frequency that is about two times the input frequency.

Digital clock frequency doubler

A circuit for converting an input signal at a first voltage level to an output signal at a second voltage level uses only thin oxide transistors. The circuit includes a first unit operating at a first power supply voltage and receiving the input signal, a second unit operating at a second power supply voltage, and a third unit coupling the first unit to the second unit. The third unit enables generation of the output signal. Use of an extra fabrication mask for thick oxide transistors is avoided by using only thin oxide transistors.

High voltage level converter using low voltage devices

A band-gap reference circuit for generation of voltages and currents independent of process, voltage, and temperature includes three inversely proportional to absolute temperature (IPTAT) current generators. The IPTAT current generators generate three currents that are added to generate a current independent of the absolute temperature. The generated current is passed through a switched capacitor resistor to generate the band-gap reference voltage across the switched capacitor resistor.

Band-gap reference circuit

A bi-directional level shifter for shifting a digital signal from a low power supply voltage level to a high power supply voltage level and vice versa includes first and second I/O terminals, a first circuit operating at a low power supply voltage, and a second circuit operating at a high power supply voltage. The first circuit and the second circuit are connected to both of the I/O terminals. When a low voltage digital signal is applied at the first I/O terminal, a high voltage digital signal is generated at the second I/O terminal. Similarly, if a high voltage digital signal is applied at the second I/O terminal, a low voltage digital signal is generated at the first I/O terminal.

Bidirectional level shifter

A power on reset (POR) circuit for providing a reset pulse signal to a chip when power supply voltage, VDD, ramps up so that the chip always starts in a known state. The POR circuit generates the reset pulse as soon as VDD exceeds an assertion voltage. The assertion voltage is independent of the ramp rate of VDD. The POR circuit is shut off as soon as the reset signal is generated, thereby drawing zero steady state current from VDD. The re-arm time for the POR circuit is very small. The POR circuit does not reset the chip when there is a dynamic change in VDD.

Power on reset circuit

A level shifter that shifts a low supply voltage input signal to a higher supply voltage output signal includes a first unit and a second unit. The first unit is connected to a high power supply voltage source and receives the input signal. The first unit acts as a startup circuit such that when the level shifter is switched on, the first unit discharges an output node if the input signal is a logic low, and when the input signal is a logic high, the first unit charges a control node to the voltage of the input signal. The second unit is connected to the first unit and the high power supply voltage source, and also receives the input signal. The second unit shifts the input signal to the higher supply voltage output signal. The level shifter operates only at the high power supply voltage.

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Gurgaon, India

Kulbhushan Misri