A3977SLP-T Allegro Microsystems Inc, A3977SLP-T Datasheet

IC MOTOR DRIVER PWM DUAL 28-TSSO

A3977SLP-T

Manufacturer Part Number
A3977SLP-T
Description
IC MOTOR DRIVER PWM DUAL 28-TSSO
Manufacturer
Allegro Microsystems Inc
Datasheets

Specifications of A3977SLP-T

Applications
Stepper Motor Driver
Number Of Outputs
1
Current - Output
±2.5A
Voltage - Load
8 V ~ 35 V
Voltage - Supply
3 V ~ 5.5 V
Operating Temperature
-20°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
28-TSSOP Exposed Pad, 28-eTSSOP, 28-HTSSOP
Operating Current
12mA
Operating Temperature Classification
Commercial
Package Type
TSSOP EP
Operating Supply Voltage (min)
3V
Operating Supply Voltage (typ)
5V
Operating Supply Voltage (max)
5.5V
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
620-1079
Features and Benefits
▪ ±2.5 A, 35 V output rating
▪ Low r
▪ Automatic current decay mode detection/selection
▪ 3.0 to 5.5 V logic supply voltage range
▪ Mixed, fast, and slow current decay modes
▪ Home output
▪ Synchronous rectification for low power dissipation
▪ Internal UVLO and thermal shutdown circuitry
▪ Crossover-current protection
Packages:
Package ED, 44-pin PLCC
with internally fused pins
Not to scale
26184.22J
Package LP, 28-pin TSSOP
with exposed thermal pad
DS(on)
outputs, 0.45 Ω source, 0.36 Ω sink typical
Microstepping DMOS Driver with Translator
SUPPLY
LOGIC
GND
GND
GND
PFD
RC
REF
RC
NC
NC
NC
1
2
10
11
12
13
15
14
16
17
7
8
9
V
DD
18
6
19
5
Pin-out Diagram
TIMER
20
PWM
4
÷8
21
3
22
2
23
1
24
Description
The A3977 is a complete microstepping motor driver, with built-
in translator. It is designed to operate bipolar stepper motors in
full-, half-, quarter-, and eighth-step modes, with output drive
capability of 35 V and ±2.5 A. The A3977 includes a fixed
off-time current regulator that has the ability to operate in
slow-, fast-, or mixed-decay modes. This current-decay control
scheme results in reduced audible motor noise, increased step
accuracy, and reduced power dissipation.
The translator is the key to the easy implementation of the
A3977. Simply inputting one pulse on the STEP input drives the
motor one step (two logic inputs determine if it is a full-, half-,
quarter-, or eighth-step). There are no phase-sequence tables,
high-frequency control lines, or complex interfaces to program.
The A3977 interface is an ideal fit for applications where a
complex microprocessor is unavailable or over-burdened.
Internal synchronous-rectification control circuitry is provided
to improve power dissipation during PWM operation.
Internal circuit protection includes thermal shutdown with
hysteresis, undervoltage lockout (UVLO) and crossover-current
protection. Special power-up sequencing is not required.
The A3977 is supplied in a choice of two power packages, a
44-pin plastic PLCC with 3 internally-fused pins on each of
four sides (suffix ED), and a thin (<1.2 mm), 28-pin TSSOP
with an exposed thermal pad (suffix LP). Both packages are
lead (Pb) free, with 100% matte tin leadframe plating.
44
V
V
25
43
BB2
BB1
REG
26
42
41
27
40
28
Dwg. PP-075-1
39
38
37
36
35
34
33
32
31
30
29
NC
CP
CP
V
GND
GND
GND
V
STEP
NC
NC
CP
REG
2
1
A3977

Related parts for A3977SLP-T

A3977SLP-T Summary of contents

Page 1

Microstepping DMOS Driver with Translator Features and Benefits ▪ ±2 output rating ▪ Low r outputs, 0.45 Ω source, 0.36 Ω sink typical DS(on) ▪ Automatic current decay mode detection/selection ▪ 3.0 to 5.5 V logic supply ...

Page 2

... A3977 Selection Guide Part Number Packing A3977KEDTR-T 450 per reel A3977SEDTR-T 450 per reel A3977SLPTR-T 4000 per reel Absolute Maximum Ratings Characteristic Load Supply Voltage Logic Supply Voltage Logic Input Voltage Range Reference Voltage Sense Voltage (DC) Output Current Operating Ambient Temperature ...

Page 3

A3977 LOGIC SUPPLY UVLO VDD AND FAULT REF. SUPPLY REF DAC RC1 4 STEP DIR RESET HOME SLEEP SR V PFD ENABLE PFD DAC Microstepping DMOS Driver with Translator FUNCTIONAL BLOCK DIAGRAM VREG ...

Page 4

A3977 LP Pin-out (TSSOP) Microstepping DMOS Driver with Translator Table 1. Microstep Resolution Truth Table MS MS Resolution Full step (2 phase Half step L H Quarter step H H Eighth step 4 Allegro ...

Page 5

A3977 ELECTRICAL CHARACTERISTICS Characteristic Output Drivers Load Supply Voltage Range Output Leakage Current Output On Resistance Body Diode Forward Voltage Motor Supply Current Control Logic Logic Supply Voltage Range Logic Input Voltage Logic Input Current Maximum STEP ...

Page 6

A3977 ELECTRICAL CHARACTERISTICS Characteristic Output Drivers (continued) Thermal Shutdown Temp. Thermal Shutdown Hysteresis UVLO Enable Threshold UVLO Hysteresis Logic Supply Current * Operation at a step frequency greater than the specifi ed minimum value is possible but not warranteed. NOTES: ...

Page 7

A3977 Device Operation. The A3977 is a complete microstep- ping motor driver with built in translator for easy operation with minimal control lines designed to operate bipolar stepper motors in full-, half-, quarter- and eighth-step modes. The current ...

Page 8

A3977 Fixed Off-Time. The internal PWM current-control circuitry uses a one shot to control the time the drivers remain off. The one shot off-time, t the selection of an external resistor (R connected from the RC timing terminal to ground. ...

Page 9

A3977 Synchronous Rectifi cation. When a PWM off-cycle is triggered by an internal fi xed off-time cycle, load current will recirculate according to the decay mode selected by the control logic. The A3977 synchronous rectifi cation fea- ture will turn ...

Page 10

A3977 Layout. The printed wiring board should use a heavy ground plane. For optimum electrical and thermal performance, the driver should be soldered directly onto the board. The load supply terminal with an electrolytic capacitor (>47 μF is ...

Page 11

A3977 Full Half Step # Step # Home state; HOME output low. Microstepping DMOS Driver with Translator Table 2. Step Sequencing (DIR = L) Phase 2 Quarter ...

Page 12

A3977 Microstepping DMOS Driver with Translator Full-Step Operation DIR = The vector addition of the output currents at any step is 100%. 12 Allegro MicroSystems, Inc. 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 ...

Page 13

A3977 Microstepping DMOS Driver with Translator Half-Step Operation DIR = The mixed-decay mode is controlled by the percent fast decay voltage (V greater than 0.6V the voltage on the PFD input ...

Page 14

A3977 Microstepping DMOS Driver with Translator Quarter-Step Operation DIR = The mixed-decay mode is controlled by the percent fast decay voltage (V greater than 0.6V the voltage on the PFD input ...

Page 15

A3977 Microstepping DMOS Driver with Translator 8 Microstep/Step Operation DIR = The mixed-decay mode is controlled by the percent fast decay voltage (V greater than 0.6V the voltage on the PFD input ...

Page 16

A3977 Terminal Name Terminal Description GND Analog and power ground SENSE Sense resistor for bridge 1 1 HOME Logic output DIR Logic Input OUT DMOS H bridge 1 output (internal) connection PFD Mixed decay setting RC ...

Page 17

A3977 16.59 ±0.08 17.53 ±0.13 44X 0.10 Microstepping DMOS Driver with Translator ED Package, 44-pin PLCC 17.53 ±0.13 16.59 ±0. 0.74 ±0.08 C 0.43 ±0.10 7.75 ±0.36 7.75 ±0.36 For Reference Only (reference JEDEC MS-018 AC) ...

Page 18

A3977 9.70 ±0. 5.00 28X 0.10 C +0.05 0.25 0.65 –0.06 Copyright ©2002-2010, Allegro MicroSystems, Inc. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail ...

Related keywords