Data Sheet

TB6560AHQ/AFG
2014-10-01
28
1. Power-on Sequence with Control Input Signals
Turn on V
DD
. Then, when the V
DD
voltage has stabilized, turn on VM
A/B
.
Hold the control input pins Low while turning on V
DD
and VM
A/B
.
(All the control input pins are internally pulled down.)
After V
DD
and VM
A/B
completely stabilizes at the rated voltages, the
RESET
and ENABLE pins can be
set High. If this sequence is not properly followed, the IC may not operate correctly, or the IC and the
peripheral parts may be damaged.
When
RESET
is released High, the CLK signal is applied and excitation is started. Only after ENABLE
is also set High, outputs are enabled. When only
RESET
is set High, outputs are disabled and only the
internal counter advances. Likewise, when only ENABLE is set High, the excitation will not be performed
even if the CLK signal is applied and the outputs will remain in the initial state.
An example of a control input sequence is shown below.
A power-off sequence should be the reverse of this sequence.
<Recommended Control Input Sequence>
2. Power Dissipation
The power dissipation of the IC can be calculated by the following equation:
P = V
DD
× I
DD
+ I
OUT
× I
OUT
× Ron × 2 phases
The higher the ambient temperature, the smaller the power dissipation.
Examine the PD-T
a
characteristic curve to determine if there is a sufficient margin in the thermal design.
3. Treatment of Heat-Radiating Fin
The heat-radiating fin pins of the TB6560AHQ/AFG (backside) are electrically connected to the backside of
the die. Thus, if a current flows to the fin, the IC may malfunction. If there is any possibility of a voltage
being generated between grounds and the fin, the fin pins should either be connected to ground or
insulated.
4. Thermal Shutdown (TSD)
When the die temperature reaches 170°C (typ.), the thermal shutdown circuit is tripped, switching the
outputs to off. There is a variation of about ±20°C in the temperature at which the thermal shutdown
circuit is tripped.
Output
Z
Z
Output current setting
Internal current setting
OUT
ENABLE
H
L
H
L
RESET
H
L
CLK
Internal current setting: Disabled;
Output OFF
Internal current setting: Enabled