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7734Q–AVR–02/12
AT90PWM81/161
12. Power Stage Controller – (PSCn)
The Power Stage Controller is a high performance waveform controller.
The Atmel AT90PWM81 includes one PSC2 block.
12.1
Features
 PWM waveform generation function (two complementary programmable outputs)
 Dead time control
 Standard mode up to 12 bit resolution
 Frequency and pulse width resolution enhancement mode (12 + 4 bits)
 Frequency up to 64Mhz
 Conditional waveform on external events (zero crossing, current sensing ...)
 All on chip PSC synchronization
 ADC synchronization with digital delay register
 Input blanking
 Overload protection function
 Abnormality protection function, emergency input to force all outputs to low level
 Center aligned and edge aligned modes synchronization
 Fast emergency stop by hardware
12.2
Overview
Many register and bit references in this section are written in general form.
 A lower case “n” replaces the PSC number, in this case 2. However, when using the register
or bit defines in a program, the precise form must be used, that is, PSOC2 for accessing PSC
2 Synchro and Output Configuration register and so on.
 A lower case “x” replaces the PSC part , in this case A or B. However, when using the register
or bit defines in a program, the precise form must be used, that is, PFRC2A for accessing
PSC n Fault/Retrigger 2 A Control register and so on.
The purpose of a Power Stage Controller (PSC) is to control power modules on a board. It has
two outputs on PSCn and four outputs on PSC2.
These outputs can be used in various ways:
 “Two Outputs” to drive a half bridge (lighting, DC motor ...)
 “One Output” to drive single power transistor (DC/DC converter, PFC, DC motor ...)
 “Four Outputs” in the case of PSC2 to drive a full bridge (lighting, DC motor ...)
Each PSC has two inputs the purpose of which is to provide means to act directly on the gener-
ated waveforms:
 Current sensing regulation
 Zero crossing retriggering
 Demagnetization retriggering
 Fault input
The PSC can be chained and synchronized to provide a configuration to drive three half bridges.
Thanks to this feature it is possible to generate a three phase waveforms for applications such
as Asynchronous or BLDC motor drive.