TB62209FG_14 Datasheet, PDF (20/52 Pages) Toshiba Semiconductor – Stepping Motor Driver IC Using PWM Chopper Type

TB62209FG
11. Current Waveform and Setting of Mixed Decay Mode
At constant current control, in current amplitude (pulsating current) Decay mode, a point from 0 to 3 can
be set using 2-bit parallel data.
NF is the point where the output current reaches the set current value. RNF is the timing for monitoring
the set current.
The smaller the MDT value, the smaller the current ripple (peak current value). Note that current decay
capability deteriorates.
CR pin
internal
CLK
waveform
DECAY MODE 0
NF
12.5%
MIXED
DECAY
MODE
f_chop
Set current value
Charge mode → NF: set current value reached → Slow
mode → Mixed decay timing → Fast mode → current
monitored (when set current value > output current) Charge
MDT
RNF
DECAY MODE 1
37.5%
MIXED
DECAY
MODE
Set current value
NF
MDT
Charge mode → NF: set current value reached → Slow
mode → Mixed decay timing → Fast mode → current
monitored (when set current value > output current) Charge
RNF
DECAY MODE 2
NF
75%
MIXED
DECAY
MODE
MDT
Charge mode → NF: set current value reached → Slow mode
→ Mixed decay timing → Fast mode → current monitored
(when set current value > output current) Charge mode
DECAY MODE 3
FAST
DECAY
MODE
Set current value
RNF
Set current value
100%
Fast mode → RNF: current monitored (when set current value
> output current) Charge mode → Fast mode
75%
50%
25%
RNF
0
20
2014-10-01