1. A signal generation apparatus, comprising:
an input stage, arranged for generating an input signal;
a bias stage, coupled to the input stage, the bias stage arranged for generating a bias signal according to the input signal and a feedback signal; and
an output stage, comprising:
an amplifier circuit, coupled to the bias stage and arranged for generating an auxiliary signal according to the bias signal; and
a feedback block, comprising:
a first feedback circuit, coupled between an output node of the signal generation apparatus and the amplifier circuit, the first feedback circuit arranged for generating a specific signal according to the auxiliary signal, wherein an output signal at the output node is derived from the specific signal; and
a second feedback circuit, coupled between the first feedback circuit and the bias stage, the second feedback circuit arranged for generating the feedback signal according to the specific signal;
wherein the input stage comprises a digital-to-analog converter (DAC) arranged for outputting a current as the input signal.
2. The signal generation apparatus of claim 1, wherein there is a linear relation between the specific signal and the auxiliary signal, there is a linear relation between the feedback signal and the specific signal, and the input signal is identical to the feedback signal.
3. The signal generation apparatus of claim 1, wherein the amplifier circuit is biased by the bias signal to operate in a class AB mode.
4. The signal generation apparatus of claim 1, wherein the auxiliary signal comprises a first auxiliary signal and a second auxiliary signal, the specific signal comprises a first specific signal and a second specific signal, and the first feedback circuit comprises:
a first feedback unit, arranged for generating the first specific signal according to the first auxiliary signal; and
a second feedback unit, arranged for generating the second specific signal according to the second auxiliary signal.
5. The signal generation apparatus of claim 4, wherein the first feedback unit comprises:
an amplifier, having an input port and an output port;
a transistor, having a control node, a first connection node and a second connection node, wherein the control node is coupled to the output port, and the second connection node is coupled to the output node of the signal generation apparatus;
a first resistive element, coupled between the input port and the first connection node, the first resistive element arranged for receiving the first auxiliary signal to generate the first specific signal at the first connection node; and
a second resistive element, coupled between a reference voltage and the first connection node.
6. The signal generation apparatus of claim 4, wherein the feedback signal comprises a first feedback signal and a second feedback signal, and the second feedback circuit comprises:
a first resistive element, coupled between the first feedback unit and the bias stage, the first resistive element arranged for generating the first feedback signal according to the first specific signal; and
a second resistive element, coupled between the second feedback unit and the bias stage, the second resistive element arranged for generating the second feedback signal according to the second specific signal.
7. The signal generation apparatus of claim 1, wherein the bias stage comprises:
an amplifier, having an input port and an output port, wherein the input port is coupled to the input stage and the second feedback circuit; and
a bias circuit, coupled to the output port of the amplifier, the bias circuit arranged for generating the bias signal according to an output signal of the amplifier.
8. A signal generation apparatus, comprising:
a digital-to-analog converter (DAC), arranged for outputting a current as an input signal;
a bias stage, coupled to the digital-to-analog converter, the bias stage arranged for generating a bias signal according to at least the input signal; and
a class AB output stage, coupled to the bias stage, the class AB output stage arranged for generating an output signal at an output node of the signal generation apparatus according to the bias signal, wherein the output signal comprises a first signal component and a second signal component, both the first signal component and the second signal component correspond to the input signal, and there is a linear relation between the output signal and the input signal;
wherein the class AB output stage further generates a feedback signal according to the bias signal, the bias stage generates the bias signal according to the input signal and the feedback signal, and the input signal is identical to the feedback signal.
9. The signal generation apparatus of claim 8, wherein the class AB output stage comprises:
an amplifier circuit, coupled to the bias stage and arranged for generating an auxiliary signal according to the bias signal; and
a feedback block, comprising:
a first feedback circuit, coupled between the output node and the amplifier circuit, the first feedback circuit arranged for generating a specific signal according to the auxiliary signal, wherein the output signal is derived from the specific signal; and
a second feedback circuit, coupled between the first feedback circuit and the bias stage, the second feedback circuit arranged for generating the feedback signal according to the specific signal.
10. The signal generation apparatus of claim 9, wherein there is a linear relation between the specific signal and the auxiliary signal, and there is a linear relation between the feedback signal and the specific signal.
11. The signal generation apparatus of claim 9, wherein the auxiliary signal comprises a first auxiliary signal and a second auxiliary signal, the specific signal comprises a first specific signal and a second specific signal, and the first feedback circuit comprises:
a first feedback unit, arranged for generating the first specific signal according to the first auxiliary signal; and
a second feedback unit, arranged for generating the second specific signal according to the second auxiliary signal.
12. The signal generation apparatus of claim 11, wherein the first feedback unit comprises:
an amplifier, having an input port and an output port;
a transistor, having a control node, a first connection node and a second connection node, wherein the control node is coupled to the output port, and the second connection node is coupled to the output node of the signal generation apparatus;
a first resistive element, coupled between the input port and the first connection node, the first resistive element arranged for receiving the first auxiliary signal to generate the first specific signal at the first connection node; and
a second resistive element, coupled between a reference voltage and the first connection node.
13. The signal generation apparatus of claim 11, wherein the feedback signal comprises a first feedback signal and a second feedback signal, and the second feedback circuit comprises:
a first resistive element, coupled between the first feedback unit and the bias stage, the first resistive element arranged for generating the first feedback signal according to the first specific signal; and
a second resistive element, coupled between the second feedback unit and the bias stage, the second resistive element arranged for generating the second feedback signal according to the second specific signal.
14. The signal generation apparatus of claim 8, wherein the bias stage comprises:
an amplifier, having an input port and an output port, wherein the input port is coupled to the digital-to-analog converter and the class AB output stage; and
a bias circuit, coupled to the output port of the amplifier, the bias circuit arranged for generating the bias signal according to an output signal of the amplifier.
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 system to assist a user with preparation and mailing of a communication requiring delivery by a special service wherein the special service has fees associated with postage and services to effect the delivery by the special service, the system comprising:
a computer accessible site that automatically provides the preparation of the communication requiring the delivery by the special service and automatic payment of the fees associated with the postage and the services required to effect the delivery by the special service;
a computer for accessing the computer accessible site via a computer network; and
a database accessible by the computer via the computer network wherein the database is remotely located with respect to the computer wherein the database stores the communication, stores instructions to assist the user to complete the communication, stores criteria regarding selection of the special service appropriate for the delivery of the communication and stores requirements to effect the delivery of the communication by the special service wherein the communication in the database is selected via the computer and further wherein the communication is automatically prepared in compliance with the requirements of the delivery by the special service and further wherein the communication is automatically mailed by the special service via the computer accessible site.
2. The system of claim 1 further comprising:
means for inputting the information by the user.
3. The system of claim 1 further comprising:
a plurality of forms stored in the database.
4. The system of claim 1 further comprising:
a directory of addresses stored in the database.
5. The system of claim 1 further comprising:
means for generating addresses necessary for delivery based on the information input by the user.
6. The system of claim 1 further comprising:
means for generating the communication based on the information input by the user.
7. The system of claim 1 further comprising:
means for suggesting mailing requirements based on the information input by the user.
8. The system of claim 1 further comprising:
means for computing postage costs and fees to the user associated with the delivery by the special service.
9. The system of claim 1 further comprising:
means for contacting a supplier necessary to complete the delivery of the communication by the special service.
10. The system of claim 1 further comprising:
means for storing the information input by the user and communications generated for the user.
11. The system of claim 1 further comprising:
means for generating a report for the user.
12. A method for assisting with preparation and automatic mailing of a communication requiring delivery by a special service, the method comprising the steps of:
providing a computer-accessible site;
providing a database accessible by a user via the computer-accessible site wherein the database is remotely located with respect to the user wherein the database stores instructions to assist the user to complete the communication, stores criteria regarding selection of the special service appropriate for the delivery of the communication, stores requirements to effect the delivery of the communication by the special service, stores the communication, and stores a directory of mailing addresses wherein the directory of mailing addresses is accessed to confirm an address of a recipient of the communication;
inputting information into the database regarding demographics of the user via the computer-accessible site wherein the requirements to effect the delivery of the communication by the special service are based on the demographics of the user;
selecting the communication in the database via the computer-accessible site;
selecting a geographical region within which the communication is to be delivered;
preparing the communication according to selection of the geographical region;
automatically mailing the communication by the special service based on the requirements to effect the delivery of the communication by the special service;
generating fees, postage costs, and special service mail provider costs; and
automatically paying the fees.
13. The method of claim 12 further comprising the step of:
determining required services for the delivery by the special service and costs associated with the delivery.
14. The method of claim 12 further comprising the step of:
providing suggestions for complying with requests for delivery by the special service based on the demographics input by the user and the communication chosen by the user.
15. The method of claim 12 further comprising the step of:
generating the communication based on information input by the user.
16. The method of claim 12 further comprising the step of:
providing the communication to the user via a display screen.
17. The method of claim 12 further comprising the step of:
providing dates and times of steps taken by a special service mail provider in mailing the communication.
18. The method of claim 12 further comprising the step of:
generating a report of actions taken by a special service mail provider.