參數(shù)資料
型號(hào): L7250
廠商: 意法半導(dǎo)體
英文描述: 5V & 12V SPINDLE AND VCM MOTORS DRIVER
中文描述: 5V的
文件頁數(shù): 26/46頁
文件大?。?/td> 478K
代理商: L7250
L7250
26/46
2.8 Spindle PWM Current Limiting
Peak motor current is limited with a fixed frequency PWM scheme that works in conjunction with the Smooth-
drive PWM rate. When the current limit threshold is reached the motor is put in brake condition, and it is re-
enabled at the beginning of the next PWM cycle if the current limiting condition is false.
Spindle current is sensed via an external resistor connected from the low side driver sources to ground. This
sense voltage is compared to an internal programmable voltage reference (Reg04H Currdac[2:0]).
There is a built in digital filter, generating a SYSCLK derived delay (20 * SYSCLK period) from the over current
event. This delay appears on both edges of the current limiting comparator.
2.9 Slew Rate Control
Closed loop Voltage Slew rate control is provided on both edges for the high and low side drivers. The slew rate
value can be set with three bits in the serial port (Reg04H Spslew[2:0]). Slew rates up to 80V/us and down to
10V/us will be controllable.
2.10Synchronous rectification
The appropriate low-side driver is enabled during the off-time phase to conduct recirculation current with a lower
voltage drop than the low side driver body diode, reducing power losses. Crossover current protection is pro-
vided to prevent shoot-through currents.
2.11Open loop and closed loop brake
Spindle braking may be done while keeping the Smoothdrive system in sync with the motor, or not.
Closed Loop Braking means ZC's are still being detected in the same way as when normally commutating. So,
all 3 motor phases are driven low, but when the window is normally opened to look for a ZC, MOTU is tri-stated.
When the ZC occurs, MOTU is driven low as the other motor phases, until the next window comes up. A mo-
tionless motor will wait for a ZC, keeping MOTU tri-stated and the other two phases low. Open loop braking
means that all 3 motor phases are driven low, and ZC's are not detected. Braking caused by a power fault is
always open loop braking.
CBRK provides control voltage for brake circuitry after power fails. An external cap on this pin is charged to 5V,
so that the cap stays charged after a power failure.
相關(guān)PDF資料
PDF描述
L7805ABD2T-TR Precision 1A regulators
L7805ACD2T-TR Precision 1A regulators
L7806ABD2T-TR Precision 1A regulators
L7806ACD2T-TR Precision 1A regulators
L7808ABD2T-TR Precision 1A regulators
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
L7250E1.2 功能描述:電源開關(guān) IC - 配電 DSD POWER RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻(最大值):85 mOhms 開啟時(shí)間(最大值):400 us 關(guān)閉時(shí)間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
L7252E2.6 功能描述:電源開關(guān) IC - 配電 DSD POWER RoHS:否 制造商:Exar 輸出端數(shù)量:1 開啟電阻(最大值):85 mOhms 開啟時(shí)間(最大值):400 us 關(guān)閉時(shí)間(最大值):20 us 工作電源電壓:3.2 V to 6.5 V 電源電流(最大值): 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOT-23-5
L725MAG 制造商:Apex Tool Group 功能描述:TAPE, 1 IN. X 25 FT, 700 SERIES, MAGNETIC END HOOK 制造商:Lufkin 功能描述:TAPE MEASURE, MAGNETIC END HOOK 25FT 1IN; Tape Measure Type:Manual; Measuring Range Max:25ft; Blade Width:1"; Case Color:Orange; Tool Body Material:ABS; Blade Finish:Yellow Clad; Blade Length:25ft ;RoHS Compliant: NA
L728 制造商:BURNDY 功能描述:L-DIE
L7290 制造商:CIPS 功能描述:CUTTER OBLIQUE SEMI FLUSH 109MM