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参数资料
| 型号： | A4987SESTR-T |
| 厂商： | Allegro Microsystems Inc |
| 文件页数： | 7/17页 |
| 文件大小： | 0K |
| 描述： | IC STEPPER MOTOR DRIVER 24QFN |
| 特色产品： | A498x Motor Driver Family |
| 标准包装： | 1 |
| 应用： | PWM 电机驱动器，步进电机驱动器 |
| 评估套件： | 可供 |
| 输出数： | 1 |
| 电流 - 输出： | ± 1A |
| 电压 - 负载： | 8 V ~ 35 V |
| 电源电压： | 3 V ~ 5.5 V |
| 工作温度： | -20°C ~ 85°C |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 24-WFQFN 裸露焊盘 |
| 供应商设备封装： | 24-QFN 裸露焊盘（4x4） |
| 包装： | 标准包装 |
| 其它名称： | 620-1404-6 |
A4987
DMOS Dual Full-Bridge PWM Motor Driver
With Overcurrent Protection
Charge Pump (CP1 and CP2). The charge pump is used to
generate a gate supply greater than that of VBB for driving the
source-side FET gates. A 0.1 μ F ceramic capacitor, should be
connected between CP1 and CP2. In addition, a 0.1 μ F ceramic
capacitor is required between VCP and VBB, to act as a reservoir
for operating the high-side FET gates.
Capacitor values should be Class 2 dielectric ±15% maximum,
or tolerance R, according to EIA (Electronic Industries Alliance)
specifications.
V REG (VREG) . This internally-generated voltage is used to
operate the sink-side FET outputs. The nominal output voltage
of the VREG terminal is 7 V. The VREG pin must be decoupled
with a 0.22 μ F ceramic capacitor to ground. V REG is internally
monitored. In the case of a fault condition, the FET outputs of the
A4987 are disabled.
Capacitor values should be Class 2 dielectric ±15% maximum,
or tolerance R, according to EIA (Electronic Industries Alliance)
specifications.
Shutdown. In the event of a fault, overtemperature (excess T J )
or an undervoltage (on VCP), the FET outputs of the A4987 are
disabled until the fault condition is removed. At power-on, the
UVLO (undervoltage lockout) circuit disables the FET outputs
and resets the translator to the Home state.
Sleep Mode ( ˉSˉ ˉLˉ ˉEˉ ˉEˉ ˉPˉ ). To minimize power consumption
when the motor is not in use, this input disables much of the
internal circuitry including the output FETs, current regulator, and
charge pump. A logic low on the Sˉ ˉLˉ ˉEˉ ˉEˉ ˉP pin puts the A4987 into
Sleep mode. When emerging from Sleep mode, in order to allow
the charge pump to stabilize, provide a delay of 1 ms before issu-
ing a logic command.
Mixed Decay Operation. The bridge operates in Mixed
5 A / div.
Fault latched
t →
Figure 1. Short-to-ground event
5 A / div.
Fixed off-time
t →
Figure 2. Shorted load (OUTxA → OUTxB) in
Slow decay mode
Decay mode, as shown in figures 5 through 7. As the trip point
is reached, the A4987 initially goes into a fast decay mode for
31.25% of the off-time, t OFF . After that, it switches to Slow Decay
mode for the remainder of t OFF . A timing diagram for this feature
appears in figure 4.
Synchronous Rectification . When a PWM-off cycle is
triggered by an internal fixed-off time cycle, load current recir-
5 A / div.
Fixed off-time
culates in Mixed Decay mode. This synchronous rectification
feature turns on the appropriate FETs during current decay, and
effectively shorts out the body diodes with the low FET R DS(ON) .
This reduces power dissipation significantly, and can eliminate
the need for external Schottky diodes in many applications. Syn-
chronous rectification turns off when the load current approaches
zero (0 A), preventing reversal of the load current.
Fast decay portion
(direction change)
t →
Figure 3. Shorted load (OUTxA → OUTxB) in Mixed decay mode
Allegro MicroSystems, LLC
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
7
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相关代理商/技术参数 |
参数描述 |
|---|---|
| A4987SLPTR | 制造商:Allegro MicroSystems LLC 功能描述:DMOS Dual Full-Bridge PWM Motor Driver |
| A4987SLPTR-T | 功能描述:IC STEPPER MOTOR DRIVER 24TSSOP 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:步进电机驱动器，1-2 相，2 相 评估套件:- 输出数:1 电流 - 输出:800mA 电压 - 负载:10 V ~ 28 V 电源电压:4.75 V ~ 5.25 V 工作温度:-20°C ~ 90°C 安装类型:表面贴装 封装/外壳:28-SOP + 2 翼片裸露焊盘 供应商设备封装:28-HSOPHC（15.2x7.9） 包装:剪切带 (CT) 其它名称:869-1268-1 |
| A4988 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:DMOS Microstepping Driver with Translator And Overcurrent Protection |
| A4988_V4 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:DMOS Microstepping Driver with Translator And Overcurrent Protection |
| A4988SETTR | 制造商:Allegro MicroSystems LLC 功能描述:DMOS Microstepping Driver |
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