US20010007434A1 - Double input buffer for track-and-hold amplifier - Google Patents
Double input buffer for track-and-hold amplifier Download PDFInfo
- Publication number
- US20010007434A1 US20010007434A1 US09/746,026 US74602600A US2001007434A1 US 20010007434 A1 US20010007434 A1 US 20010007434A1 US 74602600 A US74602600 A US 74602600A US 2001007434 A1 US2001007434 A1 US 2001007434A1
- Authority
- US
- United States
- Prior art keywords
- transistor
- input
- current
- diode
- mosfet
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
- H03K19/0175—Coupling arrangements; Interface arrangements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11C—STATIC STORES
- G11C27/00—Electric analogue stores, e.g. for storing instantaneous values
- G11C27/02—Sample-and-hold arrangements
- G11C27/024—Sample-and-hold arrangements using a capacitive memory element
- G11C27/026—Sample-and-hold arrangements using a capacitive memory element associated with an amplifier
Definitions
- the invention relates to an input buffer for a switched emitterfollower-like track-and-hold amplifier comprising an input stage with an input transistor, a first diode, a cathode side of which first diode is connected to an emitter of the input transistor, a first current source between on the one hand the junction between the cathode of the first diode and the emitter of the input transistor and on the other hand a first supply voltage line, an anode of the first diode being connected to a track-and-hold controlled emitterfollower.
- Such an input buffer is known from U.S. Pat. No. 5,583,459.
- Input buffers described therein have a current source connected between the anode of the first diode and a second supply voltage. The presence of a diode is crucial to disconnect the input signal during the hold-mode.
- An input buffer according to the invention thereto is characterised in that the first current source is a non-switched constant current source, in that a second current source is connected between a collector of the input transistor and a second supply voltage, in that a second transistor comprising a control electrode, a current input electrode and a current output electrode is connected with the control electrode to the junction between the collector of the input transistor and the second current source, with the current input electrode to the second supply voltage and with the current output electrode to the anode of the diode.
- the second current source comprises a MOSFET.
- the second transistor is a MOSFET.
- FIG. 1 shows a first embodiment of an input buffer according to the present invention
- FIG. 2 shows a second embodiment of an input buffer according to the present invention.
- FIG. 3 shows a third embodiment of an input buffer according to the present invention.
- FIG. 1 shows an input buffer 1 connected between a first supply voltage line 2 and a second supply voltage line 3 .
- An input transistor Q 1 has its emitter connected to a first side of a first current source 4 .
- the second side of current source 4 is connected to supply voltage line 2 .
- the emitter of transistor Q 1 is also connected to an emitter of transistor Q 2 .
- a base of transistor Q 2 is connected to a collector of transistor Q 2 .
- the collector of transistor Q 2 is connected to a drain of a MOSFET M 2 .
- a source of MOSFET M 2 is connected to supply voltage line 3 .
- a gate of MOSFET M 2 is connected to a collector of transistor Q 1 .
- transistor Q 2 has been described with its base connected to its collector. Functionally thereby transistor Q 2 operates as a diode, the cathode of which corresponds to the emitter of transistor Q 2 and the anode of which corresponds to the base and collector of transistor Q 2 .
- the functioning of the input buffer is independent of the choice for a single diode at the position of transistor Q 2 or for a transistor with its base and collector connected together.
- any transistor that is wired and functions as a diode, like transistor Q 2 in FIG. 1 will be called a diode.
- the base of transistor Q 2 is connected to a base of transistor 6 .
- a collector of transistor 6 is connected to the second supply voltage line 3
- an emitter of transistor 6 is connected to a collector of a transistor 7 and to a first side of a capacitor C H .
- a second side of capacitor C H is connected to the second supply voltage line 3 .
- a base of transistor 7 is connected by a line 8 to a source of track signals T.
- An emitter of transistor 7 is connected to a first side of a current source 9 .
- a second side of current source 9 is connected to first supply voltage line 2 .
- the first side of current source 9 is also connected to an emitter of a transistor 10 .
- a base of transistor 10 is connected through a line 11 to a source of hold signals H.
- a collector of transistor 10 is connected to a junction between the base of transistor Q 2 and the base of transistor 6 .
- the junction between the collector of transistor Q 1 , the gate of MOSFET M 2 and the drain of MOSFET M 1 will be called node n 1 hereinafter.
- the junction between the base of transistor Q 2 , the base of transistor 6 and the collector of transistor 10 will be called node n 2 hereinafter.
- MOSFET M 2 operates as a constant current source. Transistors Q 1 and Q 2 together with constant current source 4 operate to apply a current into node n 2 that is equal to the current input at the base of transistor Q 1 .
- MOSFET M 2 with its gate connected to node n 1 completes a loop L. Any nonlinear output impedance of MOSFET M 2 does not interact in the signal path: any nonlinear current flows through the MOSFET M 2 itself which operates as a feedback transistor.
- node n 1 has an AC content that is attenuated related to the AC content of the input signal at the base of transistor Q 1 by the gain of MOSFET M 2 . It is to be noted that MOSFET M 2 operates preferably, but not necessarily in its saturation range.
- An input buffer according to FIG. 1 can accommodate large signals at the base of transistor Q 1 .
- a threshold voltage is available for VGT of MOSFET M 1 .
- the output node n 2 can reach up to VGT of MOSFET M 2 .
- MOSFET M 2 has been described hereinbefore as a MOSFET it is also possible to make use of PNP transistors. Also although M 1 has been described as a single MOSFET it is possible to apply other kinds of current sources.
- the input buffer shown in FIG. 1 can hardly operate as a track-and-hold amplifier since during a hold-mode a voltage at node n 2 can not drop since transistor M 2 essentially drains all currents. Nevertheless it may function as an input buffer.
- FIG. 2 therefore shows a further embodiment of an input buffer according to the invention which may indeed function as a track-and-hold amplifier.
- Like elements have been indicated by the same reference numerals as in FIG. 1.
- transistor Q 2 two transistors Q 2 a and Q 2 b are now present both with their emitters connected to the emitter of transistor Q 1 and both with their bases connected to their collectors.
- the collector of transistor Q 2 a is connected to a drain of a MOSFET M 2 a .
- a source of MOSFET M 2 a is connected to supply voltage line 3 and a gate of MOSFET M 2 a is connected to node n 1 .
- the collector of transistor Q 2 b is connected to a drain of a MOSFET M 2 b .
- a source of MOSFET M 2 b is connected to supply voltage line 3 and a gate of MOSFET M 2 b is connected to node n 1 .
- the base of transistor Q 2 b is connected to node n 2 .
- node n 2 , transistor 6 , capacitor C H , and switch 52 together form a well known switched emitterfollower-like track-and-hold circuit, that is known in the art and the operation of which is considered to be known to a person skilled in the art and will therefore not further be described.
- An extra branch of transistors M 2 a and Q 2 a keeps the loop intact and allows for the branch of transistors M 2 b and Q 2 b to be removed from the loop thereby allowing node n 2 to drop.
- the loop L remains intact and is not interrupted, like in the circuit according to FIG. 1, during a hold-mode.
- node n 2 has to drop in voltage to turn off transistors Q 2 b and Q 3 .
- a further advantage of an input buffer according to the invention is a substantial decrease in the signal path of a non linear base current which itself is due to collector-base modulation of transistor 6 .
- the collector of transistor 6 is at a fixed voltage, namely the voltage VCC at the supply voltage line 3 .
- n 2 which is the same signal as the signal present at the base of transistor Q 1 . That signal because of the fixed voltage at the collector of transistor 6 leads to a nonlinear base current into transistor 6 .
- the loop L formed by the transistors M 2 and M 2 a /M 2 b respectively these nonlinear base currents are effectively eliminated.
- FIG. 3 shows a further embodiment of an input buffer according to the invention.
- Like elements have been indicated by the same reference numerals as in FIGS. 1 and 2.
- transistor Q 2 two transistors Q 2 a and Q 2 b are now present both with their emitters connected to the emitter of transistor Q 1 and both with their bases connected to their collectors.
- the collector of transistor Q 2 a is connected to a drain of a MOSFET M 2 a .
- a source of MOSFET M 2 a is connected to supply voltage line 3 and a gate of MOSFET M 2 a is connected to node n 1 .
- the collector of transistor Q 2 b is connected to a drain of a MOSFET M 2 b .
- a source of MOSFET M 2 b is connected to supply voltage line 3 and a gate of MOSFET M 2 b is connected to node n 1 .
- the base of transistor Q 2 b is connected to node n 2 .
- Node n 2 is also connected to a collector of a transistor 12 .
- a basis of transistor 12 is connected to line 11 .
- An emitter of transistor 12 is connected to a first side of a current source 13 .
- a second side of current source 13 is connected to supply voltage line 2 .
- a junction between the emitter of transistor 12 and the first side of current source 13 is connected to an emitter of a transistor 14 .
- a base of transistor 14 is connected to line 8 .
- a collector of transistor 14 is connected to the junction between the emitters of transistors Q 1 , Q 2 a and Q 2 b . Furthermore it is shown that the current source formed by MOSFET M 1 generates a current of strenght 1*I. Current source 4 generates a current of strength 2*I and current source 13 generates a current of strength 1*I.
- Transistors 7 and 10 and current source 9 together form a switch S 2 and transistors 12 and 14 and current source 13 together from a switch S 1 .
- Switches S 1 and S 2 , transistor 6 and capacitor C H together form a switched emitterfollower topology track-and-hold amplifier that is known in the art and the operation of which will not further be described inhere.
- An extra branch of transistors M 2 a and Q 2 a keeps the loop intact and allows for the branch of transistors M 2 b and Q 2 b to be removed from the loop thereby allowing node n 2 to drop.
- Switch S 1 prevents that node n 1 drops in voltage when switching takes place from track mode to hold mode.
- a current 1*I through M 1 and 2*I through current source 4 there is always a current of strenght 1*I through M 2 a and Q 2 a .
- the loop L remains intact and is not interrupted like in the circuit according to FIG. 1 when during a hold node n 2 drops in voltage to turn off transistors 6 and Q 2 .
- FIG. 1 In the embodiment according to FIG.
- node n 2 has to drop in voltage to turn off transistors Q 2 b and Q 3 .
- the switch S 1 delivers in the hold mode the current that is supplied by transistors M 2 b to node n 2 . This helps pulling down the voltage on node n 2 .
- a further advantage of an input buffer according to the invention is a substantial decrease in the signal path of a nonlinear base current which itself is due to collector-base modulation of transistor 6 .
- the collector of transistor 6 is at a fixed voltage, namely the voltage VCC at the supply voltage line 3 .
- n 2 which is the same signal as the signal present at the base of transistor Q 1 . That signal because of the fixed voltage at the collector of transistor 6 leads to a nonlinear base current into transistor 6 .
- the loop L formed by the transistors M 2 and M 2 a /m 2 b respectively these nonlinear base currents are effectively eliminated.
Landscapes
- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Computing Systems (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Amplifiers (AREA)
- Logic Circuits (AREA)
Abstract
Description
- The invention relates to an input buffer for a switched emitterfollower-like track-and-hold amplifier comprising an input stage with an input transistor, a first diode, a cathode side of which first diode is connected to an emitter of the input transistor, a first current source between on the one hand the junction between the cathode of the first diode and the emitter of the input transistor and on the other hand a first supply voltage line, an anode of the first diode being connected to a track-and-hold controlled emitterfollower.
- Such an input buffer is known from U.S. Pat. No. 5,583,459. Input buffers described therein have a current source connected between the anode of the first diode and a second supply voltage. The presence of a diode is crucial to disconnect the input signal during the hold-mode.
- It is known to embody the current source between the anode of the first diode and the second voltage supply with MOSFETs. A problem with such a current source embodied with MOSFETs is the nonlinear junction impedance thereof. When high input frequencies are used as input signals to this input buffer it is especially the nonlinear junction capacitance that plays a prominent role, at lower frequencies the nonlinear junction resistance also will play a role. The nonlinear junction impedance leads to distortion of the signal at the anode of the first diode. That distortion cannot be prevented by increasing the current through the current source since more current requires a proportionally larger current source with inherently larger nonlinear junction impedance. Furthermore a strict trade-off exists between available voltage headroom, noise and nonlinear output impedance of the current source.
- It is an object of the present invention to provide an input buffer in which the trade-off between voltage headroom, noise and nonlinear output impedance has substantially decreased.
- An input buffer according to the invention thereto is characterised in that the first current source is a non-switched constant current source, in that a second current source is connected between a collector of the input transistor and a second supply voltage, in that a second transistor comprising a control electrode, a current input electrode and a current output electrode is connected with the control electrode to the junction between the collector of the input transistor and the second current source, with the current input electrode to the second supply voltage and with the current output electrode to the anode of the diode.
- Thereby it is achieved that a nonlinear output impedance of the second transistor does not substantially interact in the signal path. Any nonlinear current flows through the second transistor itself. A consequence of connecting the second transistor according to the invention is that the junction between the collector of the input transistor and the second supply voltage has an AC content that is attenuated relative to the input AC content by the gain of the second transistor. Consequently a good current source, also in terms of noise, can be selected as the second current source.
- In a preferred embodiment of an input buffer according to the invention the second current source comprises a MOSFET.
- Thereby it is achieved that a threshold voltage is available for V
GT of that MOSFET. - In a further preferred embodiment of the invention the second transistor is a MOSFET.
- Thereby it is achieved that the voltage at the anode of the first diode can reach up to the V
GT of the second transistor. That is of advantage in situations where the second supply voltage is a low voltage. - The trade-off between voltage headrom, noise and nonlinear output impedance, known from the prior art, has substantially decreased in an input buffer according to the invention.
- The invention shall now be described with reference to the accompanying drawings in which:
- FIG. 1 shows a first embodiment of an input buffer according to the present invention;
- FIG. 2 shows a second embodiment of an input buffer according to the present invention.
- FIG. 3 shows a third embodiment of an input buffer according to the present invention.
- FIG. 1 shows an
input buffer 1 connected between a firstsupply voltage line 2 and a secondsupply voltage line 3. An input transistor Q1 has its emitter connected to a first side of a firstcurrent source 4. The second side ofcurrent source 4 is connected to supplyvoltage line 2. The emitter of transistor Q1 is also connected to an emitter of transistor Q2. A base of transistor Q2 is connected to a collector of transistor Q2. The collector of transistor Q2 is connected to a drain of a MOSFET M2. A source of MOSFET M2 is connected to supplyvoltage line 3. A gate of MOSFET M2 is connected to a collector of transistor Q1. The junction between the collector of transistor Q1 and the gate of MOSFET M2 is connected to a drain of a MOSFET M1. A source of MOSFET M2 is connected to supplyvoltage line 3. A gate of MOSFET M1 is connected through aline 5 to a source of constant voltage (not shown). In the present embodiment transistor Q2 has been described with its base connected to its collector. Functionally thereby transistor Q2 operates as a diode, the cathode of which corresponds to the emitter of transistor Q2 and the anode of which corresponds to the base and collector of transistor Q2. It is to be noted that in the present invention the functioning of the input buffer is independent of the choice for a single diode at the position of transistor Q2 or for a transistor with its base and collector connected together. In the claims any transistor that is wired and functions as a diode, like transistor Q2 in FIG. 1 will be called a diode. - The base of transistor Q2 is connected to a base of
transistor 6. A collector oftransistor 6 is connected to the secondsupply voltage line 3, an emitter oftransistor 6 is connected to a collector of atransistor 7 and to a first side of a capacitor CH. A second side of capacitor CH is connected to the secondsupply voltage line 3. A base oftransistor 7 is connected by aline 8 to a source of track signals T. An emitter oftransistor 7 is connected to a first side of acurrent source 9. A second side ofcurrent source 9 is connected to firstsupply voltage line 2. The first side ofcurrent source 9 is also connected to an emitter of atransistor 10. A base oftransistor 10 is connected through aline 11 to a source of hold signals H. A collector oftransistor 10 is connected to a junction between the base of transistor Q2 and the base oftransistor 6. The junction between the collector of transistor Q1, the gate of MOSFET M2 and the drain of MOSFET M1 will be called node n1 hereinafter. The junction between the base of transistor Q2, the base oftransistor 6 and the collector oftransistor 10 will be called node n2 hereinafter. - MOSFET M2 operates as a constant current source. Transistors Q1 and Q2 together with constant
current source 4 operate to apply a current into node n2 that is equal to the current input at the base of transistor Q1. MOSFET M2 with its gate connected to node n1 completes a loop L. Any nonlinear output impedance of MOSFET M2 does not interact in the signal path: any nonlinear current flows through the MOSFET M2 itself which operates as a feedback transistor. As a consequence node n1 has an AC content that is attenuated related to the AC content of the input signal at the base of transistor Q1 by the gain of MOSFET M2. It is to be noted that MOSFET M2 operates preferably, but not necessarily in its saturation range. - It is to be noted that interaction in the signal path of any nonlinear output impedance of MOSFET M1 has substantially decreased. The loop formed by MOSFET M2, transistor Q2, transistor Q1 and
current source 4 effectively decreases any consequences of nonlinearity in the output impedance of MOSFET M1 such that AC signals at the input of Q1 have been attenuated at node n1 by the gain of MOSFET M2. - An input buffer according to FIG. 1 can accommodate large signals at the base of transistor Q1. A threshold voltage is available for VGT of MOSFET M1. Also the output node n2 can reach up to VGT of MOSFET M2.
- Though MOSFET M2 has been described hereinbefore as a MOSFET it is also possible to make use of PNP transistors. Also although M1 has been described as a single MOSFET it is possible to apply other kinds of current sources.
- It is to be noted that the input buffer shown in FIG. 1 can hardly operate as a track-and-hold amplifier since during a hold-mode a voltage at node n2 can not drop since transistor M2 essentially drains all currents. Nevertheless it may function as an input buffer.
- FIG. 2 therefore shows a further embodiment of an input buffer according to the invention which may indeed function as a track-and-hold amplifier. Like elements have been indicated by the same reference numerals as in FIG. 1. Instead of transistor Q2 two transistors Q2 a and Q2 b are now present both with their emitters connected to the emitter of transistor Q1 and both with their bases connected to their collectors. The collector of transistor Q2 a is connected to a drain of a MOSFET M2 a. A source of MOSFET M2 a is connected to supply
voltage line 3 and a gate of MOSFET M2 a is connected to node n1. The collector of transistor Q2 b is connected to a drain of a MOSFET M2 b. A source of MOSFET M2 b is connected to supplyvoltage line 3 and a gate of MOSFET M2 b is connected to node n1. The base of transistor Q2 b is connected to node n2. - It is to be noted that node n2,
transistor 6, capacitor CH, and switch 52 together form a well known switched emitterfollower-like track-and-hold circuit, that is known in the art and the operation of which is considered to be known to a person skilled in the art and will therefore not further be described. - An extra branch of transistors M2 a and Q2 a keeps the loop intact and allows for the branch of transistors M2 b and Q2 b to be removed from the loop thereby allowing node n2 to drop. Thus the loop L remains intact and is not interrupted, like in the circuit according to FIG. 1, during a hold-mode. In the embodiment according to FIG. 2 node n2 has to drop in voltage to turn off transistors Q2 b and Q3.
- A further advantage of an input buffer according to the invention is a substantial decrease in the signal path of a non linear base current which itself is due to collector-base modulation of
transistor 6. The collector oftransistor 6 is at a fixed voltage, namely the voltage VCC at thesupply voltage line 3. During tracking there is a signal at node n2 which is the same signal as the signal present at the base of transistor Q1. That signal because of the fixed voltage at the collector oftransistor 6 leads to a nonlinear base current intotransistor 6. However, due to the loop L formed by the transistors M2 and M2 a/M2 b, respectively these nonlinear base currents are effectively eliminated. - FIG. 3 shows a further embodiment of an input buffer according to the invention. Like elements have been indicated by the same reference numerals as in FIGS. 1 and 2. Instead of transistor Q2 two transistors Q2 a and Q2 b are now present both with their emitters connected to the emitter of transistor Q1 and both with their bases connected to their collectors. The collector of transistor Q2 a is connected to a drain of a MOSFET M2 a. A source of MOSFET M2 a is connected to supply
voltage line 3 and a gate of MOSFET M2 a is connected to node n1. The collector of transistor Q2 b is connected to a drain of a MOSFET M2 b. A source of MOSFET M2 b is connected to supplyvoltage line 3 and a gate of MOSFET M2 b is connected to node n1. The base of transistor Q2 b is connected to node n2. Node n2 is also connected to a collector of atransistor 12. A basis oftransistor 12 is connected toline 11. An emitter oftransistor 12 is connected to a first side of acurrent source 13. A second side ofcurrent source 13 is connected to supplyvoltage line 2. A junction between the emitter oftransistor 12 and the first side ofcurrent source 13 is connected to an emitter of atransistor 14. A base oftransistor 14 is connected toline 8. A collector oftransistor 14 is connected to the junction between the emitters of transistors Q1, Q2 a and Q2 b. Furthermore it is shown that the current source formed by MOSFET M1 generates a current ofstrenght 1*I.Current source 4 generates a current ofstrength 2*I andcurrent source 13 generates a current ofstrength 1*I. -
Transistors current source 9 together form a switch S2 andtransistors current source 13 together from a switch S1. Switches S1 and S2,transistor 6 and capacitor CH together form a switched emitterfollower topology track-and-hold amplifier that is known in the art and the operation of which will not further be described inhere. - An extra branch of transistors M2 a and Q2 a keeps the loop intact and allows for the branch of transistors M2 b and Q2 b to be removed from the loop thereby allowing node n2 to drop. Switch S1 prevents that node n1 drops in voltage when switching takes place from track mode to hold mode. By the choices of a current 1*I through M1 and 2*I through
current source 4 there is always a current ofstrenght 1*I through M2 a and Q2 a. Thereby the loop L remains intact and is not interrupted like in the circuit according to FIG. 1 when during a hold node n2 drops in voltage to turn offtransistors 6 and Q2. In the embodiment according to FIG. 2 node n2 has to drop in voltage to turn off transistors Q2 b and Q3. The switch S1 delivers in the hold mode the current that is supplied by transistors M2 b to node n2. This helps pulling down the voltage on node n2. - A further advantage of an input buffer according to the invention is a substantial decrease in the signal path of a nonlinear base current which itself is due to collector-base modulation of
transistor 6. The collector oftransistor 6 is at a fixed voltage, namely the voltage VCC at thesupply voltage line 3. During tracking there is a signal at node n2 which is the same signal as the signal present at the base of transistor Q1. That signal because of the fixed voltage at the collector oftransistor 6 leads to a nonlinear base current intotransistor 6. However, due to the loop L formed by the transistors M2 and M2 a/m2 b, respectively these nonlinear base currents are effectively eliminated.
Claims (7)
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP99204526 | 1999-12-24 | ||
EP99204526.0 | 1999-12-24 | ||
EP99204526 | 1999-12-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010007434A1 true US20010007434A1 (en) | 2001-07-12 |
US6323700B2 US6323700B2 (en) | 2001-11-27 |
Family
ID=8241083
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/746,026 Expired - Lifetime US6323700B2 (en) | 1999-12-24 | 2000-12-21 | Double input buffer for track-and-hold amplifier |
Country Status (6)
Country | Link |
---|---|
US (1) | US6323700B2 (en) |
EP (1) | EP1157389B1 (en) |
JP (1) | JP2003518858A (en) |
KR (1) | KR100741183B1 (en) |
DE (1) | DE60040593D1 (en) |
WO (1) | WO2001048759A1 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100747808B1 (en) * | 2000-03-28 | 2007-08-08 | 코닌클리즈케 필립스 일렉트로닉스 엔.브이. | A track and hold amplifier |
KR100477564B1 (en) * | 2002-08-19 | 2005-03-18 | 이디텍 주식회사 | track and hold circuit of the A/D converter built in display output system |
US7782096B2 (en) * | 2007-08-08 | 2010-08-24 | Texas Instruments Incorporated | Track-and-hold circuit with low distortion |
US7804337B2 (en) * | 2007-10-23 | 2010-09-28 | Texas Instruments Incorporated | Method and apparatus of SFDR enhancement |
JP5122526B2 (en) * | 2009-01-15 | 2013-01-16 | 日本電信電話株式会社 | Track and hold circuit |
JP6830079B2 (en) * | 2018-03-30 | 2021-02-17 | 日本電信電話株式会社 | Track and hold circuit |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
IT1213307B (en) * | 1986-07-29 | 1989-12-20 | Sgs Microelettronica Spa | VOLTAGE REPEATER CIRCUIT FOR LOADS WITH RESISTIVE COMPONENT WITH HARMONIC DISTORTION COMPENSATION. |
JPS63200397A (en) * | 1987-02-16 | 1988-08-18 | Nec Corp | Sample-hold circuit |
US4806790A (en) * | 1987-02-16 | 1989-02-21 | Nec Corporation | Sample-and-hold circuit |
US5198782A (en) * | 1991-01-15 | 1993-03-30 | Crystal Semiconductor | Low distortion amplifier output stage for dac |
JP2680753B2 (en) * | 1991-07-31 | 1997-11-19 | 三洋電機株式会社 | Buffer amplifier |
JP3332991B2 (en) * | 1993-05-12 | 2002-10-07 | 日本テキサス・インスツルメンツ株式会社 | Drive circuit |
US5442309A (en) * | 1993-12-14 | 1995-08-15 | Advanced Micro Devices, Inc. | Low distortion output stage |
JP2570185B2 (en) | 1994-07-08 | 1997-01-08 | 日本電気株式会社 | Sample hold circuit |
US5457418A (en) * | 1994-12-05 | 1995-10-10 | National Semiconductor Corporation | Track and hold circuit with an input transistor held on during hold mode |
US5654665A (en) * | 1995-05-18 | 1997-08-05 | Dynachip Corporation | Programmable logic bias driver |
JPH0964665A (en) * | 1995-08-28 | 1997-03-07 | Nec Eng Ltd | Semiconductor integrated circuit |
WO1997028603A1 (en) * | 1996-02-01 | 1997-08-07 | Philips Electronics N.V. | Distortion compensation for a capacitively loaded follower |
-
2000
- 2000-12-13 EP EP00990727A patent/EP1157389B1/en not_active Expired - Lifetime
- 2000-12-13 DE DE60040593T patent/DE60040593D1/en not_active Expired - Lifetime
- 2000-12-13 KR KR1020017010755A patent/KR100741183B1/en not_active IP Right Cessation
- 2000-12-13 WO PCT/EP2000/012620 patent/WO2001048759A1/en active Application Filing
- 2000-12-13 JP JP2001548394A patent/JP2003518858A/en active Pending
- 2000-12-21 US US09/746,026 patent/US6323700B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JP2003518858A (en) | 2003-06-10 |
EP1157389A1 (en) | 2001-11-28 |
EP1157389B1 (en) | 2008-10-22 |
DE60040593D1 (en) | 2008-12-04 |
WO2001048759A1 (en) | 2001-07-05 |
KR20010102362A (en) | 2001-11-15 |
KR100741183B1 (en) | 2007-07-19 |
US6323700B2 (en) | 2001-11-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP2713167B2 (en) | Comparator | |
US20140247082A1 (en) | Fast Voltage Level Shifter Circuit | |
US4498057A (en) | Power amplifier with power supply switching | |
US6323700B2 (en) | Double input buffer for track-and-hold amplifier | |
US6069509A (en) | Output stage with slewing control means | |
CN101192811A (en) | Variable gain amplifier circuit | |
KR970005825B1 (en) | Differential current source circuit | |
KR960016811B1 (en) | Circuitry for suppressing audible switch on and off noise | |
US6903610B2 (en) | Operational amplifying circuit and push-pull circuit | |
JPH0595271A (en) | Emitter-coupled logic circuit | |
JP2570185B2 (en) | Sample hold circuit | |
JP3973486B2 (en) | Variable gain amplifier and differential amplifier | |
KR860000906B1 (en) | Sample circuit | |
US4166983A (en) | Circuit for limiting the output voltage of an amplifier | |
JP3795282B2 (en) | Transmission path switching circuit | |
US5262688A (en) | Operational amplifier circuit | |
KR100394301B1 (en) | Btl amplifier circuit | |
JP3833089B2 (en) | Variable gain amplifier | |
JP2797694B2 (en) | Electronic switch circuit | |
KR920002129Y1 (en) | Audio amp for recording and playing | |
JPH0746051A (en) | Bias circuit of fet | |
KR910001076Y1 (en) | D.c. amplifier circuit without pop noise | |
KR880003431Y1 (en) | Power saving circuit for non-switching power amplifier | |
KR910005774Y1 (en) | Amplification circuit for control signal | |
JPH0138976Y2 (en) |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: U.S. PHILIPS CORPORATION, NEW YORK Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HOOGZAAD, GIAN;REEL/FRAME:011621/0362 Effective date: 20010201 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
AS | Assignment |
Owner name: NXP B.V., NETHERLANDS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:U.S. PHILIPS CORPORATION;REEL/FRAME:018635/0755 Effective date: 20061127 |
|
FEPP | Fee payment procedure |
Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |
|
AS | Assignment |
Owner name: ST WIRELESS SA, SWITZERLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NXP B.V.;REEL/FRAME:037624/0831 Effective date: 20080728 |
|
AS | Assignment |
Owner name: ST-ERICSSON SA, SWITZERLAND Free format text: CHANGE OF NAME;ASSIGNOR:ST WIRELESS SA;REEL/FRAME:037683/0128 Effective date: 20080714 Owner name: ST-ERICSSON SA, EN LIQUIDATION, SWITZERLAND Free format text: STATUS CHANGE-ENTITY IN LIQUIDATION;ASSIGNOR:ST-ERICSSON SA;REEL/FRAME:037739/0493 Effective date: 20150223 |