POWER SUPPLY CONTROL DEVICE
An electronic device is for controlling multiple switching power circuits in a power supply system. Each switching power circuit has a power clock for controlling switching of a supply side switch that enables charging. The device has respective power clock delay units. Each respective power clock delay unit provides a respective power clock at a predetermined delay based on a respective input clock. The respective predetermined delays are chosen so that said switching of respective different supply side switches occurs at respective different points in time. Advantageously the conducted emission in high frequency bands is reduced.
1 . An electronic device for controlling multiple switching power circuits in a power supply system, each switching power circuit having a power clock for controlling switching of a supply side switch that enables charging, the device comprising respective power clock delay units, each respective power clock delay unit configured to provide a respective power clock at a predetermined delay based on a respective input clock, the respective predetermined delays being so that said switching of respective different supply side switches occurs at respective different points in time.
2 . The device as claimed in claim 1 , wherein the power clock delay units are coupled in series wherein the input clock of a respective power clock delay unit is coupled to the power clock of the preceding power clock delay unit.
3 . The device as claimed in claim 1 , wherein the delay unit is an analog delay cell.
4 . The device of claim 3 , wherein the analog delay cell comprises a control current source configured to a control current for determining the predetermined delay.
5 . The device of claim 4 , wherein the control current is predetermined during design of the device.
6 . The device of claim 4 , wherein the control current is adjustable via a control signal.
7 . The device of claim 4 , wherein respective control currents for respective analog delay cells are programmable.
8 . The device of claim 4 , wherein the device has a delay control input, and respective control currents for respective analog delay cells are arranged for being adjusted via the delay control input.
9 . The device as claimed in claim 1 , wherein the device comprises a digital control unit configured to control said multiple switching power circuits.
10 . The device as claimed in claim 1 , wherein the device comprises said multiple switching power circuits.
11 . The device as claimed in claim 10 , wherein each of the multiple switching power circuits has a respective data input configured to control the respective switching power circuit.
12 . The device as claimed in claim 10 , wherein the device comprises said multiple supply side switches coupled to said switching power circuits.
13 . An integrated circuit comprising at least one electronic device according to claim 1 .
14 . In an electronic device ter configured to control multiple switching power circuits in a power supply system, each switching power circuit having a power clock for controlling switching of a supply side switch that enables charging, a method comprises providing respective power clock delays to the switching power circuits, each respective power clock delay providing a respective power clock at a predetermined delay based on a respective input clock, the respective predetermined delays being so that said switching of respective different supply side switches occurs at respective different points in time.
15 . The method of claim 14 , wherein providing the delay comprises controlling a current source for generating a control current for determining the predetermined delay.
16 . The method of claim 15 , wherein the method comprises predetermining the control current during design of the device.
17 . The method of claim 15 , wherein the method comprises adjusting the control current via a control signal.
18 . The method of claim 15 , wherein the method comprises programming the respective control currents for respective delays.