参数资料
型号: A3955SLBTR
厂商: Allegro Microsystems Inc
文件页数: 9/14页
文件大小: 0K
描述: IC MOTOR DRIVER PWM FULL 16-SOIC
标准包装: 1,000
应用: 步进电机驱动器
输出数: 1
电流 - 输出: ±1.5A
电压 - 负载: 4.5 V ~ 50 V
电源电压: 4.5 V ~ 5.5 V
工作温度: -20°C ~ 85°C
安装类型: 表面贴装
封装/外壳: 16-SOIC(0.295",7.50mm 宽)
供应商设备封装: 16-SOIC W
包装: 带卷 (TR)
A3955
Full-Bridge PWM Microstepping Motor Driver
reference value, resulting in increased motor performance in
microstepping applications.
For a given level of ripple current, slow decay affords the lowest
PWM frequency, which reduces heating in the motor and driver
IC due to a corresponding decrease in hysteretic core losses and
switching losses respectively. Slow decay also has the advantage
that the PWM load current regulation can follow a more rapidly
increasing reference before the PWM frequency drops into the
audible range. For these reasons slow-decay mode is typically
used as long as good current regulation can be maintained.
Under some circumstances slow-decay mode PWM can fail to
maintain good current regulation:
1) The load current will fail to regulate in slow-decay mode
due to a suf ? ciently negative back-EMF voltage in conjunction
with the low voltage drop across the load during slow decay
recirculation. The negative back-EMF voltage can cause the load
current to actually increase during the slow decay off time.A
negative back-EMF voltage condition commonly occurs when
driving stepping motors because the phase lead of the rotor
typically causes the back-EMF voltage to be negative towards
the end of each step (see ? gure 3A).
2) When the desired load current is decreased rapidly, the slow
rate of load current decay can prevent the current from following
the desired reference value.
3) When the desired load current is set to a very low value, the
current-control loop can fail to regulate due to its minimum duty
cycle, which is a function of the user-selected value of t OFF and
the minimum on-time pulse width t on(min) that occurs each time
the PWM latch is reset.
Fast Current-Decay Mode. When V PFD 0.8 V, the device
is in fast current-decay mode (both the sink and source drivers
are disabled when the load current reaches I TRIP ). During the
? xed off-time, the load inductance causes the current to ? ow
from ground to the load supply via the motor winding, ground-
clamp and ? yback diodes (see ? gure 1). Because the full motor
supply voltage is across the load during fast-decay recirculation,
the rate of load current decay is rapid, producing a high ripple
current for a given ? xed off-time (see ? gure 2). This rapid rate of
decay allows good current regulation to be maintained at the cost
of decreased average current accuracy or increased driver and
motor losses.
A — Slow-Decay
B — Fast-Decay
C — Mixed-Decay
Figure 3 — Sinusoidal Drive Currents
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
8
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相关代理商/技术参数
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A3955SLBTR/21-60301-01 制造商:Allegro MicroSystems 功能描述:FOR JABIL / QUANTUM
A3955SLBTR-T 功能描述:IC MOTOR DRIVER PWM FULL 16-SOIC RoHS:是 类别:集成电路 (IC) >> PMIC - 电机和风扇控制器,驱动器 系列:- 标准包装:1 系列:- 应用:直流电机驱动器,步进电机驱动器 评估套件:- 输出数:1 或 2 电流 - 输出:750mA 电压 - 负载:10 V ~ 40 V 电源电压:4.5 V ~ 5.5 V 工作温度:-20°C ~ 70°C 安装类型:表面贴装 封装/外壳:24-BFSOP(0.295",7.50mm 宽) 供应商设备封装:24-SOP 包装:Digi-Reel® 其它名称:MTS62C19A-HS105DKR
A3956SLB 制造商:Allegro MicroSystems LLC 功能描述:ELECTRONIC COMPONENT
A3957SA 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:FULL-BRIDGE PWM MICROSTEPPING MOTOR DRIVER
A3957SLB 制造商:Allegro MicroSystems LLC 功能描述: