参数资料
型号: L6258
厂商: STMICROELECTRONICS
元件分类: 运动控制电子
英文描述: STEPPER MOTOR CONTROLLER, 1.5 A, PDSO36
封装: ROHS COMPLIANT, SOP-36
文件页数: 13/32页
文件大小: 364K
代理商: L6258
PWM current control loop
L6258
20/32
Doc ID 4588 Rev 10
Verr_out = -(ic Zc) so ic = -(Verr_out
)
because ib = icwe have:
Vsense
= -(Verr_out
)
In the case of no external RC network is used to compensate the error amplifier, the typical
open loop transfer function of the error plus the sense amplifier is something with a gain
around 80dB and a unity gain bandwidth at 400kHz. In this case the situation of the total
transfer function Aloop, given by the sum of the AxdB and BxdB is:
Figure 8.
Aloop bode plot (uncompensated)
The BODE diagram shows together the error amplifier open loop transfer function, the Ax
function and the resultant total Aloop given by the following equation:
AloopdB = AxdB + BxdB
The total Aloop has an high DC gain of 78.1dB with a bandwidth of 15KHz, but the problem
in this case is the stability of the system; in fact the total Aloop cross the zero dB axis with a
slope of -40dB/decade.
Now it is necessary to compensate the error amplifier in order to obtain a total Aloop with an
high DC gain and a large bandwidth. Aloop must have enough phase margin to guarantee
the stability of the system.
A method to reach the stability of the system, using the RC network showed in the block
diagram, is to cancel the load pole with the zero given by the compensation of the error
amplifier.
The transfer function of the Bx block with the compensation on the error amplifier is:
1
Zc
-------
1
Rb
--------
1
Zc
-------
Bx
Verr_out
Vsense
------------------------
Zc
Rb
--------
==
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L6258_07 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:PWM controlled high current DMOS universal motor driver
L6258A 制造商:未知厂家 制造商全称:未知厂家 功能描述:Stepper Motor Controller/Driver
L6258E 功能描述:马达/运动/点火控制器和驱动器 Dual Full Bridge RoHS:否 制造商:STMicroelectronics 产品:Stepper Motor Controllers / Drivers 类型:2 Phase Stepper Motor Driver 工作电源电压:8 V to 45 V 电源电流:0.5 mA 工作温度:- 25 C to + 125 C 安装风格:SMD/SMT 封装 / 箱体:HTSSOP-28 封装:Tube
L6258E_07 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:PWM controlled high current DMOS universal motor driver
L6258EA 制造商:STMICROELECTRONICS 制造商全称:STMicroelectronics 功能描述:PWM controlled high current DMOS universal motor driver