Envelope tracking power management circuit
An envelope tracking (ET) power management circuit is provided. The ET power management circuit includes an amplifier circuit(s) configured to output a radio frequency (RF) signal at a defined power level corresponding to a direct current, an alternating current, and an ET modulated voltage received by the amplifier circuit(s). The ET power management circuit can operate in a high-power ET mode when the defined power level exceeds a defined power level threshold and the RF signal is modulated to include no more than a defined number of resource blocks. The ET power management includes two ET tracker circuitries each generating a respective ET modulated voltage and two charge pump circuitries each generating a respective current. In the high-power ET mode, both charge pump circuitries are activated to each provide a reduced current to the amplifier circuit, thus helping to reduce a footprint and cost of the ET power management circuit.
1. An envelope tracking (ET) power management circuit, comprising:
an amplifier circuit comprising an amplifier input and an amplifier output and configured to output a radio frequency (RF) signal at the amplifier output at a defined power level corresponding to a direct current, an alternating current, and an ET modulated voltage received at the amplifier input;
a first circuit coupled to the amplifier input and configured to generate a first ET modulated voltage, a first direct current, and a first alternating current;
a second circuit coupled to the amplifier input and configured to generate a second ET modulated voltage, a second direct current, and a second alternating current; and
control circuitry coupled to the first circuit and the second circuit, the control circuitry configured to configure the first circuit and the second circuit to operate in a high-power ET mode in response to the defined power level exceeding a defined power threshold and the RF signal comprising less than or equal to a defined number of resource blocks (RBs).
2. The ET power management circuit of claim 1 wherein the first direct current substantially equals the second direct current.
3. The ET power management circuit of claim 1 wherein the defined power threshold equals 24 dBm and the defined number of RBs equals 100 RBs.
4. The ET power management circuit of claim 1 further comprising switching circuitry configured to couple the first circuit and the second circuit to the amplifier input, wherein:
the first circuit comprises:
first ET tracker circuitry configured to generate the first ET modulated voltage; and
first charge pump circuitry configured to generate the first direct current and the first alternating current;
the second circuit comprises:
second ET tracker circuitry configured to generate the second ET modulated voltage; and
second charge pump circuitry configured to generate the second direct current and the second alternating current; and
the control circuitry is further configured to activate the first charge pump circuitry and the second charge pump circuitry to provide the first direct current and the second direct current to the amplifier input.
5. The ET power management circuit of claim 4 wherein, in the high-power ET mode, the control circuitry is further configured to:
control the switching circuitry to couple the first charge pump circuitry and the second charge pump circuitry to the amplifier input to provide the first direct current and the second direct current to the amplifier input; and
activate a selected ET tracker circuitry among the first ET tracker circuitry and the second ET tracker circuitry in a selected circuit among the first circuit and the second circuit to provide a selected ET modulated voltage among the first ET modulated voltage and the second ET modulated voltage to the amplifier input.
6. The ET power management circuit of claim 5 wherein, in the high-power ET mode, the control circuitry is further configured to:
control the switching circuitry to couple the selected ET tracker circuitry to the amplifier input to provide the selected ET modulated voltage to the amplifier input;
control a selected charge pump circuitry in the selected circuit to provide a selected alternating current among the first alternating current and the second alternating current to the amplifier input; and
control the switching circuitry to couple the selected charge pump circuitry to the amplifier input to provide the selected alternating current to the amplifier input.
7. The ET power management circuit of claim 4 wherein the control circuitry is further configured to:
configure the first circuit and the second circuit to operate in a normal-power ET mode in response to the defined power level being less than or equal to the defined power threshold and the RF signal comprising more than the defined number of RBs;
activate selected charge pump circuitry among the first charge pump circuitry and the second charge pump circuitry in a selected circuit among the first circuit and the second circuit to provide a selected direct current among the first direct current and the second direct current and a selected alternating current among the first alternating current and the second alternating current to the amplifier input; and
activate selected ET tracker circuitry in the selected circuit to provide a selected ET modulated voltage among the first ET modulated voltage and the second ET modulated voltage to the amplifier input.
8. The ET power management circuit of claim 4 further comprising inductor-based buck-boost circuitry configured to generate a common supply voltage based on a battery voltage, wherein the first ET tracker circuitry and the second ET tracker circuitry are further configured to generate the first ET modulated voltage and the second ET modulated voltage, respectively, based on the common supply voltage.