Current estimation in a power converter
Current detection circuitry for generating an average inductor current signal indicative of an average inductor current during an operational cycle of power converter circuitry, the current detection circuitry comprising: circuitry for generating a peak inductor current signal indicative of a peak inductor current during the operational cycle; and circuitry for applying a ripple current estimate signal, indicative of an estimate of half of a ripple current in the power converter circuitry, to the peak inductor current signal to generate the average inductor current signal, wherein the ripple current is equal to a difference between the average inductor current and the peak inductor current.
1 . Current detection circuitry for generating an average inductor current signal indicative of an average inductor current during an operational cycle of power converter circuitry, the current detection circuitry comprising:
circuitry for applying a ripple current estimate signal indicative of an estimate of half of a ripple current in the power converter circuitry to a peak inductor current signal, indicative of a peak inductor current during the operational cycle, wherein the ripple current is equal to a difference between the average inductor current and the peak inductor current,
wherein the circuitry for applying the ripple current estimate signal comprises comparison circuitry for performing a comparison of a first period equal to half the duration of a charging phase of the power converter circuitry to a second period equal to a time taken for the inductor current in the power converter circuitry to reach the average current threshold,
wherein the ripple current estimate signal is based, at least in part, on a result of the comparison.
2 . Current detection circuitry according to claim 1 , further comprising digital counter circuitry configured to generate a first count value indicative of the first period and a second count value indicative of the second period.
3 . Current detection circuitry according to claim 2 , wherein the comparison circuitry comprises digital comparison circuitry operative to compare the first count value to the second count value and to generate a comparator output signal based on the comparison.
4 . Current detection circuitry according to claim 3 , wherein the comparison circuitry further comprises digital accumulator circuitry configured to increase or decrease a ripple current estimate based on the comparator output signal.
5 . Current detection circuitry according to claim 1 , further comprising circuitry for generating the peak inductor current signal, wherein the circuitry for generating the peak inductor current signal comprises control circuitry configured to receive a first signal indicative of a target output voltage and a second signal indicative of an actual output voltage of the power converter circuitry and to generate the peak inductor current signal based on the first and second received signals.
6 . Current detection circuitry according to claim 1 , wherein the circuitry for applying the ripple current estimate signal is configured to generate and apply an additional DC voltage to the peak inductor current signal.
7 . Current detection circuitry according to claim 6 , wherein the comparison circuitry is configured to modify the additional DC voltage.
8 . Current detection circuitry according to claim 1 , further comprising current monitor circuitry configured to generate a signal indicative of an actual inductor current in the power converter circuitry during operation of the power converter circuitry.
9 . Current detection circuitry according to claim 8 , further comprising comparator circuitry configured to compare the signal indicative of the actual inductor current during operation of the power converter circuitry to a threshold that is based on the average inductor current signal.
10 . Current detection circuitry according to claim 1 , further comprising circuitry for generating a scaling factor k, wherein the scaling factor k is a ratio of the total period of an operational cycle of the boost converter circuitry to an active period of the operational cycle, wherein an active period is a period in which current flows through the inductor during the operational cycle.
11 . Current detection circuitry according to claim 10 , further comprising multiplier circuitry for applying the scaling factor k to a signal within a control loop of the current detection circuitry.
12 . Current detection circuitry according to claim 10 , further comprising divider circuitry outside of the control loop for applying the scaling factor k to a signal within a control loop of the current detection circuitry.
13 . Current detection circuitry according to claim 1 , wherein the ripple current estimate signal is based on a supply voltage to the power converter circuitry, an inductance of an inductor of the power converter circuitry and a charging period of the inductor.
14 . Current detection circuitry according to claim 1 , wherein the power converter circuitry comprises boost converter circuitry.
15 . Power converter circuitry comprising current detection circuitry according to claim 1 .
16 . An integrated circuit comprising power converter circuitry according to claim 15 .
17 . A host device comprising current detection circuitry according to claim 1 .
18 . A host device according to claim 17 , wherein the host device comprises a laptop, notebook, netbook or tablet computer, a gaming device, a games console, a controller for a games console, a virtual reality (VR) or augmented reality (AR) device, a mobile telephone, a portable audio player, a portable device, an accessory device for use with a laptop, notebook, netbook or tablet computer, a gaming device, a games console, a VR or AR device, a mobile telephone, a portable audio player or other portable device.
19 . A host device comprising power converter circuitry according to claim 15 .
20 . A host device according to claim 19 , wherein the host device comprises a laptop, notebook, netbook or tablet computer, a gaming device, a games console, a controller for a games console, a virtual reality (VR) or augmented reality (AR) device, a mobile telephone, a portable audio player, a portable device, an accessory device for use with a laptop, notebook, netbook or tablet computer, a gaming device, a games console, a VR or AR device, a mobile telephone, a portable audio player or other portable device.