tb62212ftag TOSHIBA Semiconductor CORPORATION, tb62212ftag Datasheet - Page 21

• Manufacturer Part Number: tb62212ftag
• Description: Pwm Chopper Type Dual-stepping Motor Driver
• Manufacturer: TOSHIBA Semiconductor CORPORATION

Calculating the Oscillation Frequency
810/8 = 101 kHz.
IC Power Dissipation
consumed by the logic block and the charge pump circuit.
Power Consumed by the Power Transistor
power consumed by the transistors of a single H-bridge.
becomes the perfect rectangular waveform can be calculated as follows.
Power Consumed by the Logic Block and IM
the one at stop.
switching) is connected to V
Power Dissipation
consumption current to change.
(calculated with R
The OSC oscillation frequency (f
When C
At this time, the actual chopping frequency of the stepping motor is 1/8 the OSC oscillation frequency, which is,
IC power dissipation is classified into two: power consumed by transistors in the output block and power
Power is consumed by the upper and lower transistors of the H-bridges. The following formula expresses the
The average power dissipation for output under 2-phase excitation operation when the output current waveform
Under the conditions of R
Power dissipation of the logic block and IM is calculated as follows by separating it into the one at operation and
Output section (total of current consumed by the circuits connected to V
Power dissipation is calculated as follows:
Thus, power dissipation for a single unit (P) is determined as follows by (2) and (3) above.
In the actual motor current, the effective current changes depending on the rotation frequency, which causes the
For thermal design on the board, evaluate by mounting the IC and complete the design with adequate margin.
f
osc
I (IM2) = 8.0 mA (typ.): at operation
P (IM) = 24 (V) × 0.008 (A)...........................................................................................................(3)
P (out) = I
P (out unit) = 0.6 (A)
P = P (out unit) + P (IM) = 1.776 (W)
osc
= 220 pF is connected, f
= 61820 × C (pF) ^−0.8043 (kHz)
= 0.192 (W)
out
= 1.584 (W)
on
(A) × V
= 2.2 Ω which is the total Ron of upper and lower transistor)
on
M
(24 V).
(upper/lower) = 2.2 Ω (@1.0 A), I
2
DS
× 2.2 (Ω) × H-switch × 2............................................................................(2)
(V) × H-switch × 2 = I
osc
osc
) and the chopping frequency (f
= 810 kHz.
(Chopping reference frequency)
out
21
2
× R
out
on
(upper/lower) × H-switch × 2 ............(1)
(Peak: Max) = 0.6 A, V
chop
) can be calculated by the following formula:
M
and current consumed by output
M
= 24 V,
TB62212FTAG
2010-10-05