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參數(shù)資料
| 型號： | LB11975 |
| 廠商： | Sanyo Electric Co.,Ltd. |
| 元件分類： | 基準(zhǔn)電壓源/電流源 |
| 英文描述： | High-Speed CD-ROM Spindle Motor Driver IC |
| 中文描述： | 高速的CD - ROM主軸馬達(dá)驅(qū)動IC |
| 文件頁數(shù)： | 10/12頁 |
| 文件大?。?/td> | 118K |
| 代理商： | LB11975 |
Overview of Reverse Torque Braking
(This circuit uses a direct PWM drive technique and allows the current limiter to operate during reverse torque braking.)
In earlier direct PWM motor drivers, speed control was implemented by applying PWM to only one (either the upper or
lower) output transistor. With this type of driver, the regenerative current formed during reverse torque braking operated
as a short-circuit braking. As a result problems such as the coil current exceeding the limit value and I
O
max being
exceeded, would occur. To prevent these problems, the LB11975 switches both the upper and lower side output
transistors during reverse torque braking to suppress the generation of overcurrents due to regenerative currents when the
PWM is off and allows the optimal design of drive currents.
Supplementary Documentation
Coil current during reverse torque braking
(1) Earlier ICs, with the lower side transistor was switched and the upper side transistor used for current detection (RF)
During reverse torque braking, when the coil current increases and the limit is reached, the lower side output
transistor is turned off. At this time the regenerative current flows through the upper side transistor. The circuit path is
as follows:
Coil
→
upper side diode
→
V
CC
→
RF
→
upper side transistor
→
coil
During regeneration, the upper side transistor is on and the back EMF that occurs at the upper side transistor’s emitter
pin has a low potential, and since the upper side transistor is fully on at that point, the circuit functions as short-circuit
braking.
Even if the regenerative current results in the RF voltage reaching the limit voltage, since the upper side transistor
cannot be turned off, the limit circuit will not operate and a coil current in excess of I
O
max may occur.
(2) Earlier ICs, with the upper side transistor was switched and the upper side transistor used for current detection (RF)
During reverse torque braking, when the coil current increases and the limit is reached, the upper side output
transistor is turned off. At this time the regenerative current flows through the lower side transistor. The circuit path is
as follows:
Coil
→
lower side transistor
→
ground
→
lower side diode
→
coil
During regeneration, the lower side transistor is on and the back EMF that occurs at the lower side transistor’s
collector pin has a high potential, and since the lower side transistor is fully on at that point, the circuit functions as
short-circuit braking.
Since the regenerative current does not flow through the RF pin, the current limiter circuit does not operate, and a
current in excess of I
O
max may occur in the lower side transistor.
No. 6497-10/12
LB11975
IN1
IN2
IN3
Reverse rotation is detected with this timing.
Hall comparator
(IN1, IN2, and IN3)
waveforms
Figure 3 Reverse Rotation Timing Chart
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| LB11980H | Monolithic Digital IC For VCR Capstan Three-Phase Brushless Motor Driver |
| LB11981 | Three-Phase Sensorless Motor Driver |
| LB11985 | VCR Capstan Motor Brushless Motor Driver |
| LB11985H | VCR Capstan Motor Brushless Motor Driver |
| LB11988 | Refrigerator Fan Motor Driver |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LB11980H | 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:Monolithic Digital IC For VCR Capstan Three-Phase Brushless Motor Driver |
| LB11981 | 制造商:SANYO 制造商全稱:Sanyo Semicon Device 功能描述:Three-Phase Sensorless Motor Driver |
| LB11981-TLM-E | 制造商:Sony Semiconductor Solutions Division 功能描述: |
| LB11983 | 制造商:未知廠家 制造商全稱:未知廠家 功能描述: |
| LB11983-E | 功能描述:馬達(dá)/運(yùn)動/點(diǎn)火控制器和驅(qū)動器 FAN MOTOR RoHS:否 制造商:STMicroelectronics 產(chǎn)品:Stepper Motor Controllers / Drivers 類型:2 Phase Stepper Motor Driver 工作電源電壓:8 V to 45 V 電源電流:0.5 mA 工作溫度:- 25 C to + 125 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:HTSSOP-28 封裝:Tube |
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