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1. How to Turn on the Power
Turn on V
. When the voltage has stabilized, turn on V
DD
In addition, set the Control Input pins to Low when inputting the power.
(All the Control Input pins are pulled down internally.)
Once the power is on, the CLK signal is received and excitation advances when RESET goes high and
excitation is output when ENABLE goes high. If only RESET goes high, excitation won't be output and
only the internal counter will advance. Likewise, if only ENABLE goes high, excitation won't advance even
if the CLK signal is input and it will remain in the initial state.
The following is an example:
<Recommended Control Input Sequence>
CLK
RESET
ENABLE
OUT
Internal current Setting
Output current setting
2. Calculating the Setting Current
To perform constant-current operations, it is necessary to configure the base current using an external
resistor. If the voltage on the N
Ex.: If the maximum current value is 1 A, the external resistance will be 0.5 W.
3. PWM Oscillator Frequency (External Condenser Setting)
An external condenser connected to the OSC pin is used to internally generate a saw tooth waveform. PWM
is controlled using this frequency. Toshiba recommends 100 to 3300 pF for the capacitance, taking
variations between ICs into consideration.
Approximation: f
osc
4. Power Dissipation
The IC power dissipation is determined by the following equation:
P = V
× I
+ I
DD
DD
OUT
The higher the ambient temperature, the smaller the power dissipation.
Check the PD-Ta curve, and be sure to design the heat dissipation with a sufficient margin.
5. Heat Sink Fin Processing
The IC fin (rear) is electrically connected to the rear of the chip. If current flows to the fin, the IC will
malfunction. If there is any possibility of a voltage being generated between the IC GND and the fin, either
ground the fin or insulate it.
H
L
H
L
H
Z
L
Z
Internal current setting: Invariable
Output OFF
(B) pin is 0.5 V (with a torque of 100%) or greater, it will not charge.
FA
= 1/(C
× 1.5 × (10/C
osc
osc
× Ron × 2 drivers
.
MA/B
Output
Internal current setting: Variable
+ 1)/66) × 1000 kHz
26
TB6560AHQ/AFG
2007-05-24
V1.0.3
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