US 5,212,456 A · Wide-dynamic-range amplifier with a charge-pump load and energizing circuit

Abstract

An amplifier has a first stage employing a pair of differentially connected NMOS amplifier transistors, a second stage composed of a bipolar current mirror circuit and two charge pumps. Each charge pump may be a switching voltage multiplier circuit without the conventional output capacitor. The outputs of the two charge pumps are connected, respectively, to the collector of the current-mirror output transistor and to the commonly connected sources of the NMOS amplifier transistors. Each charge pump serves as both a pulse-voltage energizing source and a load to the amplifier. The amplifier is incorporated with a high-current NMOS transistor in an integrated circuit, wherein one differential input of the amplifier is connected to the source of the driver transistor at which an external load, e.g. a motor, may be connected. The output (collector) of the differential amplifier is connected to the gate of the NMOS driver transistor so that the load current through the driver transistor is held regulated to a value proportional to the input or reference voltage that is applied to the other input of the differential amplifier. The peak pulse voltage of each charge pump is greater than the DC supply voltage from which the driver transistor and the two charge pumps are energized so that the dynamic range of both the input control voltage and the amplifier output to the gate of the NMOS driver transistor is much greater than the DC supply voltage to the integrated circuit.

Claims13

Dependent claims

A linear voltage amplifier circuit comprising:

a DC voltage supply conductor;
a final amplifier stage having a high impedance-output;
an oscillator for producing signal pulses;
a charge pump circuit means connected to said DC voltage supply conductor for being energized therefrom, having an input connected to said oscillator, and having an output with a substantial source impedance,
for producing, at said charge-pump-means output under open circuit conditions, voltage pulses at the frequency of said oscillator signal pulses, said voltage pulses having peak values substantially greater than the voltage applied to said DC voltage supply conductor, said high impedance-output of said final amplifier stage being connected to said charge-pump-means output, said substantial source impedance of said output of said charge pump circuit means serving as a load to said final-amplifier-stage transistor and the high voltage pulses of said charge-pump means serving as a high voltage energizing source to said amplifier transistor.

2 more elements

An integrated driver circuit of the kind formed in a silicon chip that includes (a) a driver transistor having a control terminal and two output terminals;

(b) a supply voltage pad to which one of said driver-transistor output terminals is connected;
(c) a driver-circuit output pad to which the other of said driver-transistor output terminals is connected and to which an external driver load may be connected;
and (d) a linear amplifier means having one input connected to said driver circuit output pad and including one high-impedance output connected to said driver-transistor input terminal, for regulating the voltage at said driver-circuit output pad, wherein the improvement comprises:
one charge pump circuit means connected to said supply voltage pad for receiving excitation therefrom and having a high-impedance output connected to said one output of said amplifier means for providing an energizing voltage and load impedance to said one output of said amplifier means, said linear amplifier means being additionally for sinking the output current from said one charge pump means, said energizing voltage of said one charge pump means being a series of voltage pulses having a peak amplitude that is substantially greater than a DC supply voltage that may be externally applied to said supply voltage pad.

1 more element

Dependencies are inferred from the claim text.

Wide-dynamic-range amplifier with a charge-pump load and energizing circuit

Life of this patent

Wide-dynamic-range amplifier with a charge-pump load and energizing circuit

Life of this patent

Abstract

Claims13