1. A charge pump comprising:
a voltage controlled oscillator (VCO) to produce a clock signal having a variable frequency in response to an error signal;
a pump stage to produce an output voltage in response to the clock signal;
a differential amplifier to produce the error signal in response to the output voltage and a reference voltage; and
a bias circuit to bias the VCO by modifying a DC voltage component of the error signal, the bias circuit capable of commanding a lower nonzero VCO output frequency during a warm-up mode and a higher nonzero VCO frequency during a loading mode, wherein the bias circuit includes at least one diode-connected transistor to modify the DC voltage component of the error signal, the bias circuit further includes two diode-connected transistors and two switches to conditionally couple the two diode-connected transistors to an output node of the differential amplifier, and wherein the two switches are closed during the warm-up mode, and only one of the switches is closed during the loading mode.
2. The charge pump of claim 1 wherein the differential amplifier comprises an output stage with an NMOS load device.
3. The charge pump of claim 2 wherein the two diode-connected transistors and two switches form a plurality of current paths to modify a DC current through the NMOS load device.
4. A method comprising:
starting a charge pump circuit with a first nonzero internal clock frequency during a warm-up mode by biasing an error signal fed from an output node of an error amplifier to a voltage controlled oscillator (VCO) with a first DC voltage by closing two switches coupled to the output node of the error amplifier; and
operating the charge pump circuit with a second nonzero internal clock frequency during a loading mode by biasing the error signal fed to the VCO with a second DC voltage by closing one of the two switches coupled to the output of the error amplifier.
5. The method of claim 4 wherein the first nonzero internal clock frequency is lower than the second nonzero internal clock frequency.
6. The method of claim 4 further comprising supplying a charge pump output voltage to a circuit within a flash memory device.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A sensing device for enabling joystick control of software or hardware, in at least one rotational direction, the sensing device being configured to interact with a printed surface having text andor graphics and coded data printed thereon, the coded data being indicative of a plurality of reference points of the printed surface, the sensing device including:
a sensor for sensing at least some of the coded data as the sensing device is used to interact with at least some of the text andor graphics on the printed surface;
processing means for processing at least some of the sensed coded data to generate indicating data, the indicating data being indicative of: at least one dimension of rotational orientation of the sensing device relative to the printed surface; and a position of the sensing device relative to the surface;
a transmitter for transmitting the indicating data, the indicating data being useable to enable the control of the software or hardware.
2. The sensing device of claim 1, wherein the rotational orientation includes at least a roll of the sensing device relative to the printed surface.
3. The sensing device of claim 2, configured to determine the dimension of rotational orientation by determining a rotational position of at least some of the sensed coded data in a frame of image data captured by the sensor.
4. The sensing device of claim 1, wherein the rotational orientation includes at least one of yaw and pitch of the sensing device relative to the surface.
5. The sensing device of claim 4, configured to determine the dimension of the at least one of yaw and pitch by determining a perspective distortion of at least some of the sensed coded in a frame of image data captured by the sensor.
6. The sensing device of claim 5, wherein the coded data includes periodic elements, and the sensing device is configured to determine the at least one of yaw and pitch by determining the perspective distortion based on the relative positions of at least some of the periodic elements in the frame of image data.
7. The sensing device according to claim 1, wherein the coded data is substantially invisible.
8. The sensing device according to claim 7, wherein the text andor graphics includes an icon that indicates, to a human, that interacting with the icon with the sensing device will cause the sensing device to be used as a controller.
9. The sensing device of claim 1, further including a memory for storing an identity of the sensing device, the indicating data including the identity, thereby enabling identification of the sensing device from which the indicating data was transmitted.