Data Sheet

TB6560AHQ/AFG
2014-10-01
17
10. Current Control Modes (Effects of Decay Modes)
• Increasing the current (sine wave)
• Decreasing the current with a high decay rate (The current decay rate in Mixed Decay mode is the ratio
between the time in Fast-Decay mode (discharge time after MDT) and the remainder of the period.)
• Decreasing the current with a low decay rate (The current decay rate in Mixed Decay mode is the ratio
between the time in Fast-Decay mode (discharge time after MDT) and the remainder of the period.)
During Mixed Decay and Fast Decay modes, if the predefined current level is less than the output
current at the RNF (current monitoring point), the Charge mode in the next chopping cycle will
disappear (though the current control mode is briefly switched to Charge mode in actual operations for
current sensing) and the current is controlled in Slow and Fast Decay modes (mode switching from Slow
Decay mode to Fast Decay mode at the MDT point).
Note: The above figures are rough illustration of the output current. In actual current waveforms, transient response
curves can be observed.
Slow
Slow
Slow
Slow
Fast
Fast
Charge
Charge
Fast
Charge
Fast
Charge
Predefined
Curren
t Level
Predefined
Curre
nt Level
Slow
Slow
Fast
Charge
Fast
Charge
Slow
Fast
Slow
Fast
Charge
Since the current decay
s quickly, it can be
decreased
to the predefined value in a short time.
Predefined
Curre
nt Level
Predefined
Curr
ent Level
Slow
Fast
Charge
Slow
Fast
Charge
Fast
Slow
Fast
Slow
Since the current decays slowly, decreasing the current
to the predefi
ned value takes a long time (or the current
cannot be pr
operly decreased to the predefined value).
Predefined
Curren
t Level
Predefined
Cur
rent Level