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US 7,126,423 B1Granted
Differential difference amplifier for amplifying small signals close to zero volts
AssigneeSiTel Semiconductor B.V.
InventorMarinus W. Kruiskamp
Life of this patent
Estimating the term…
Abstract
A differential difference amplifier is provided for amplifying an input signal having a magnitude close to zero (or a negative supply voltage) and adding an offset voltage to the amplified input signal.
Claims22
A circuit for amplifying an input signal close to a ground voltage or a negative supply voltage, the circuit comprising:
- a differential difference amplifier having first and second differential input pairs, the first differential input pair coupled across a voltage to be amplified;
- a first load device coupled between first and second inputs for the second differential input pair;
- a second load device coupled in a feedback loop between an output for the differential difference amplifier and the second input for the second differential input pair;
- and
- a voltage offset device coupled between an input for the first differential input pair and an input for the second differential input pair.
2 more elements
A battery monitoring apparatus comprising:
- a sensor coupled to a battery such that a charge current flows through said sensor when said battery is charging and a discharge current flows through said sensor when said battery is discharging;
- an offset voltage generation circuit capable of generating an offset voltage;
- a differential difference amplifier for amplifying a voltage sense signal on a sense resistor and adding said offset voltage to the amplified voltage sense signal, said differential difference amplifier having first and second differential input pairs, the first differential input pair coupled across said voltage sense signal to be amplified;
- a first load device coupled between first and second inputs for the second differential input pair;
- a second load device coupled in a feedback loop between an output for the differential difference amplifier and the second input for the second differential input pair;
- and
- wherein said offset voltage generation circuit is coupled between an input for the first differential input pair and an input for the second differential input pair.
4 more elements
Dependencies are inferred from the claim text.