- 您现在的位置：买卖IC网 > PDF目录1773 > A3981KLPTR-T (Allegro Microsystems Inc)IC MOTOR DVR MICROSTEP 28-TSSOP PDF资料下载
参数资料
| 型号： | A3981KLPTR-T |
| 厂商： | Allegro Microsystems Inc |
| 文件页数： | 10/43页 |
| 文件大小： | 0K |
| 描述： | IC MOTOR DVR MICROSTEP 28-TSSOP |
| 标准包装： | 1 |
| 系列： | * |
| 应用： | * |
| 输出数： | * |
| 电流 - 输出： | * |
| 电压 - 负载： | * |
| 电源电压： | * |
| 工作温度： | * |
| 安装类型： | 表面贴装 |
| 封装/外壳： | 28-SOIC（0.173"，4.40mm 宽）裸露焊盘 |
| 供应商设备封装： | 28-TSSOP 裸露焊盘 |
| 包装： | 标准包装 |
| 其它名称： | 620-1458-6 |
第1页第2页第3页第4页第5页第6页第7页第8页第9页当前第10页第11页第12页第13页第14页第15页第16页第17页第18页第19页第20页第21页第22页第23页第24页第25页第26页第27页第28页第29页第30页第31页第32页第33页第34页第35页第36页第37页第38页第39页第40页第41页第42页第43页
A3981
Automotive, Programmable Stepper Driver
starts and the bridge is switched into one of two decay modes,
slow decay or fast decay :
? Slow decay is most effective when the current is rising from
step to step, and it occurs when the phase winding is effectively
shorted by switching-on either both high-side FETs or both low-
side FETs in the full bridge.
? Fast decay is most effective when the current is falling from
step to step, and it occurs when the voltage on the phase is
reversed.
One disadvantage of fast decay is the increased current ripple in
the phase winding. However, this can be reduced while main-
taining good current control, by using a short time of fast decay
followed by slow decay for the remainder of the PWM off-time.
This technique is commonly referred to as mixed decay.
The A3981 provides two methods to determine the PWM
frequency: fixed off-time and fixed frequency. At power-up the
default mode is fixed off-time. Fixed frequency can be selected
through the serial interface. Fixed off-time provides a marginal
improvement in current accuracy over a wide range of current
levels. Fixed frequency provides a fixed fundamental frequency
to allow more precise supply filtering for EMC reduction. In both
cases the PWM off-time will not be present if the peak current
limit is not attained during the PWM on-time.
Phase Current Table
The relative phase currents are defined by the Phase Current table
(table 7). This table contains 64 lines and is addressed by the Step
Angle Number, where Step Angle Number 0 corresponds to 0° or
360°. The Step Angle Number is generated internally by the step
sequencer, which is controlled either by the STEP and DIR inputs
or by the step change value from the serial input. The Step Angle
Number determines the motor position within the 360° electri-
cal cycle and a sequence of Step Angle Numbers determines the
motor movement. Note that there are four full mechanical steps
per 360° electrical cycle.
Each line of the Phase Current table (table 7) has a 6-bit value per
phase to set the DAC level for that phase, plus an additional bit
per phase to determine the current direction for that phase. The
Step Angle Number sets the electrical angle of the stepper motor
in one-sixteenth microsteps, approximately equivalent to electri-
cal steps of 5.625°.
On first power-up or after a VDD power-on reset, the Phase Cur-
rent table values are reset to define a sinusoidal current profile
and the Step Angle Number is set to 8, equivalent to the electri-
cal cycle 45° position. This position is defined as the “home”
position. The maximum current in each phase, I PMAX , is defined
by the sense resistor and the Maximum Current setting (bits
MXI[0..1]) in Configuration Register 0. The phase currents for
each entry in the Phase Current table are expressed as a percent-
age of this maximum phase current.
When using the STEP and DIR inputs to control the stepper
motor, the A3981 automatically increases or decreases the Step
Angle Number according to the step sequence associated with
the selected step mode. The default step mode, reset at power-
up or after a power on reset, is full step. Half-, quarter-, and
sixteenth-step sequences are also available when using the STEP
and DIR inputs, and are selected using the logical OR of the MS0
and MS1 inputs and the MS0 and MS1 bits in Configuration Reg-
ister 0. The eighth-step sequence is shown in the Phase Current
table for reference only.
When using the serial interface to control the stepper motor, a
step change value (6-bit) is input through the serial interface to
increase or decrease the Step Angle Number. The step change
value is a two’s complement (2’sC) number, where a positive
value increases the step angle and a negative value decreases
the step angle. A single step change in the Step Angle Number is
equivalent to a single one-sixteenth microstep. Therefore, for cor-
rect motor movement, the step change value should be restricted
to no greater than 16 steps, positive or negative.
This facility enables full control of the stepper motor at any
microstep resolution up to and including sixteenth-step, plus
the ability to change microstep resolution “on-the-fly” from one
microstep to the next.
In both control input method cases, the resulting Step Angle
Number is used to determine the phase current value and current
direction for each phase, based on the Phase Current table. The
decay mode is determined by the position in the Phase Current
table and the intended direction of rotation of the motor.
Diagnostics
The A3981 integrates a number of diagnostic features to protect
the driver and load as far as possible from fault conditions and
extreme operating environments. At the system level the supply
voltages and the chip temperature are monitored. A number of
these features automatically disable the current drive to protect
the outputs and the load. Others only provide an indication of
the likely fault status, as shown in the Fault table (table 1). A
single diagnostic output pin (DIAG) can be programmed through
the serial interface to provide several different internal signals.
At power-up, or after a power-on-reset the DIAG pin outputs a
simple Fault Output flag which will be low if a fault is present.
The Fault Output flag remains low while the fault is present or if
one of the latched faults (for example, a bridge short circuit) has
been detected and the outputs disabled.
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
10
相关PDF资料 |
PDF描述 |
|---|---|
| A3982SLB-T | IC MOTOR DRIVER STEPPER 24-SOIC |
| A3983SLP-T | IC MICRO STEPPING DRIVER 24-TSSO |
| A3984SLP-T | IC MICRO STEPPING DRIVER 24-TSSO |
| A3986SLDTR-T | IC DRIVER MICROSTEPPING 38-TSSOP |
| A3987SLPTR-T | IC DRIVER MICROSTEPPING 24-TSSOP |
相关代理商/技术参数 |
参数描述 |
|---|---|
| A3982 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:DMOS Stepper Motor Driver with Translator |
| A3982_13 | 制造商:ALLEGRO 制造商全称:Allegro MicroSystems 功能描述:DMOS Stepper Motor Driver with Translator |
| A3982SLB | 功能描述:IC MOTOR DRIVER STEPPER 24-SOIC RoHS:否 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 |
| A3982SLB-T | 功能描述:IC MOTOR DRIVER STEPPER 24-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 |
| A3982SLB-T | 制造商:Allegro MicroSystems 功能描述:Motor Driver IC |
发布紧急采购，3分钟左右您将得到回复。