Voltage level interface circuit with separate reference signal input and folded cascode structure
AssigneeU.S. Philips Corporation
InventorsDaniel J. Linebarger, Nasrollah Saeed Navid
Life of this patent
Estimating the term…
Abstract
A low-voltage, high-speed voltage level interface circuit for signal level translation between circuits operating at different supply voltages. The circuit utilizes a folded cascode structure with a separate reference voltage to achieve high-speed and low-voltage performance. Voltage divider circuits are provided at the signal and reference inputs.
Claims10
A voltage level interface circuit comprising:
- (a) a first circuit having a signal input circuit and output,
- (b) a first supply voltage connected to and supplying a voltage V.sub.1 to operate the first circuit,
- (c) a second circuit having signal input and output,
- (d) a second supply voltage connected to and supplying a voltage V.sub.2 to operate the second circuit,
- (e) V.sub.1 not being equal to V.sub.2,
- (f) means connecting the first circuit signal input to receive an input signal V.sub.s,
- (g) means connecting the first circuit signal output to the second circuit signal input,
- (h) means connecting the second circuit signal output to output an output signal V.sub.o,
- (i) said first circuit having a reference signal circuit with a reference input separate from the first circuit signal input circuit,
- (j) means connecting a reference signal to the first circuit reference input;
- and
- (k) said first and second circuits form a folded cascode structure.
A voltage level interface circuit comprising:
- (a) a first circuit having a signal input circuit and output,
- (b) a first supply voltage connected to and supplying a voltage V.sub.1 to operate the first circuit,
- (c) a second circuit having signal input and output,
- (d) a second supply voltage connected to and supplying a voltage V.sub.2 to operate the second circuit,
- (e) V.sub.1 being greater than V.sub.2,
- (f) means connecting the first circuit signal input to receive an input signal V.sub.5,
- (g) means connecting the first circuit signal output to the second circuit signal input,
- (h) means connecting the second circuit signal output to output an output signal V.sub.o,
- (i) said first circuit having a reference signal circuit with a reference input separate from the first circuit signal input circuit, and
- (j) means connecting a reference signal to the first circuit reference input.
In a level shifting circuit comprising first and second circuits operating at different supply voltages and having a signal input to the first circuit and a signal output from the second circuit, the improvement comprising:
- (a) said first and second circuits forming a cascode structure that provides a signal path from the signal input to the signal output,
- (b) a reference circuit, separate from the said signal path and connected to the second circuit, for receiving a reference voltage for controlling the operation of said second circuit.
Dependencies are inferred from the claim text.