How it Works
Allegro
Loading...
A8905CLB
Datasheet
12 pgs167.11 Kb0

Allegro A8905CLB Datasheet

8905
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
8905
Data Sheet
26301.3
3-PHASE BRUSHLESS DC MOTOR
CONTROLLER/DRIVER WITH BACK-EMF SENSING
The A8905CLB isw a three-phase brushless dc motor controller/
driver for use with CD-ROM or DVD drives. The three half-bridge
LOAD
SUPPLY
C
D2
C
WD
C
ST
OUT
GROUND
GROUND
OUT
OUT
CENTERTAP
BRAKE
C
RES
A
B
C
1
2
3
4
5
6
7
8
9
9
10
11
V
BB
BOOST
CHARGE
PUMP
COMMUTATION
DELAY
SERIAL PORT
MUX
FLL
C
24
D1
23
DATA IN
22
CLOCK
21
CHIP SELECT
20
RESET
19
GROUND
18
GROUND
DATA OUT
17
OSCILLATOR
16
LOGIC
V
15
DD
SUPPLY INDEX
14
1312
FILTER
Dwg. PP-040-1
ABSOLUTE MAXIMUM RATINGS
at T
= +25°C
A
Load Supply Voltage, VBB. . . . . . 14 V
Output Current, I Logic Supply Voltage, V
. . . . . . . . ±1.25 A
OUT
. . . . 6.0 V
DD
Logic Input Voltage Range,
. . . . . . . -0.3 V to VDD + 0.3 V
V
IN
Package Power Dissipation,
. . . . . . . . . . . . . . . . See Graph
P
D
Operating Temperature Range,
. . . . . . . . . . . . . . 0°C to +70°C
T
A
Junction Temperature, T
. . . +150°C†
J
Storage Temperature Range,
. . . . . . . . . . . . -55°C to +150°C
T
S
† Fault conditions that produce excessive junction temperature will activate device thermal shutdown circuitry. These conditions can be tolerated, but should be avoided.
DISCONTINUED PRODUCT
Output current rating may be restricted to a value determined by system concerns and factors. These include: system duty cycle and timing, ambient temperature, and use of any heatsinking and/or forced cooling. For reliable operation, the specified maximum junction temperature should not be exceeded.
— FOR REFERENCE ONLY
A serial port allows the user to program various features and modes of operation, such as the speed control parameters, startup current limit, sleep mode, diagnostic modes, and others.
APPLICATIONS
■ CD-ROMs
■ DVDs
FEATURES
■ DMOS Outputs
■ Low r
■ Startup Commutation Circuitry
■ Back-EMF Commutation Circuitry
■ Serial Port Interface
■ Frequency-Locked Loop Speed Control
■ Tachometer Signal Input
■ Programmable Start-Up Current
■ Diagnostics Mode
■ Sleep Mode
■ Linear Current Control
■ Internal Current Sensing
■ Dynamic Braking Through Serial Port
■ Power-Down Dynamic Braking
■ System Diagnostics Data Out
■ Data Out Ported in Real Time
■ Internal Thermal Shutdown Circuitry
Always order by complete part number, e.g., A8905CLB .
DS(on)
8905
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
FUNCTIONAL BLOCK DIAGRAM
CENTERTAP
C
WD
INDEX
OSC
DATA IN
14
23
10
16
OUT
OUT
OUT
3
LOGIC
SUPPLY
A
B
C
FREQUENCY-
LOCKED LOOP
SERIAL PORT MUX
CHIP
SELECT
2221
CLOCK
COMMUTATION
RESET
15
V
DD
LOGIC
FCOM
BLANK
1720
C
D1
24 2
COMMUTATION
DELAY
WATCHDOG
TIMER
CHARGE
PUMP
OUT
DATA
C
D2
START-UP
OSC.
TSD
C
ST
4
BRAKE
BRAKE
13
FILTER
11
LOGIC
SEQUENCE
CURRENT CONTROL
C
RES
12
BOOST
CHARGE
PUMP
V
BB
R
LOAD
1
SUPPLY
5
OUT
A
8
OUT
B
9
OUT
C
S
6-7
GROUND
18-19
GROUND
Dwg. FP-034-1
2.5
R = 6°C/W
θJT
2.0
1.5
R = 55°C/W
1.0
θJA
0.5
0
25
ALLOWABLE PACKAGE POWER DISSIPATION in WATTS
50 75 100 125 150
TEMPERATURE in °C
Dwg. GP-019B
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
Copyright © 1998 Allegro MicroSystems, Inc.
8905
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
ELECTRICAL CHARACTERISTICS at T
= +25°C, V
A
= 5.0 V
DD
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Logic Supply Voltage V
Logic Supply Current I
DD
DD
Operating 4.5 5.0 5.5 V
Operating — 7.5 10 mA
Sleep Mode — — 1.5 mA
Load Supply Voltage V
Thermal Shutdown T
Thermal Shutdown Hys. ∆T
BB
J
J
Operating 4.5 — 14 V
— 165 — °C —20—°C
Output Drivers
Output Leakage Current I
Total Output ON Resistance r
Output Sustaining Voltage V
DS(on)
DS(sus)
Clamp Diode Forward Voltage V
DSX
F
VBB = 14 V, V
VBB = 14 V, V
I
= 600 MA — 1.1 1.4 Ω
OUT
V
= 14 V, I
BB
= 14 V — 1.0 300 µA
OUT
= 0 V — -1.0 -300 µA
OUT
= I
OUT
(MAX), L = 3 mH 14 — — V
OUT
IF = 1.0 A — 1.25 1.5 V
Control Logic
Logic Input Voltage V
Logic Input Current I
DATA Output Voltage V
V
CST Current I
IN(0)
V
IN(1)
IN(0)
I
IN(1)
OUT(0)
OUT(1)
CST
INDEX, RESET, CLK, -0.3 — 1.5 V
CHIP SELECT, OSC, BRAKE 3.5 — 5.3 V
V
= 0 V — — -0.5 µA
IN
V
= 5.0 V — — 1.0 µA
IN
I
= 500 µA — — 1.5 V
OUT
I
= -500 µA 3.5 — — V
OUT
Charging 14 20 28 µA Discharging -14 -20 -28 µA
CST Threshold V
Filter Current I
CSTH
V
CSTL
FILTER
Charging 7.0 10 15 µA
2.1 2.5 2.9 V
— 500 — mV
Discharging -7.0 -10 -15 µA
CD Current I
CD
Leakage, V
Charging 14 22 28 µA
= 2.5 V — 5.0 — nA
FILTER
Discharging -26 -35 -66 µA
CD Current Matching — I
CD Threshold V
CWD Current I
CD
CWD
CD(DISCHRG)/ICD(CHRG)
Charging 14 22 28 µA
1.7 2.2 2.3 —
— 2.5 — V
Continued next page …
8905
3-PHASE BRUSHLESS DC MOTOR CONTROLLER/DRIVER
ELECTRICAL CHARACTERISTICS continued
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
CWD Threshold Voltage V
Max. FLL Oscillator Frequency f
I
(MAX) Accuracy — I
OUT
BRAKE Threshold V
Transconductance Gain g
Centertap Resistors R
V
OSC
TL
TH
BRK
m
CT
Back-EMF Hysteresis — V
VDD = 5.1 V, T
VDD = 4.5 V, T
= 1 A — ±20 — %
OUT
- V
BEMF
= 25°C20——MHz
A
= 70°C—10—MHz
A
at 152540mV
CTAP
FCOM Transition -15 -25 -40 mV
0.80 0.85 0.95 V
2.4 2.75 3.0 V
1.4 1.7 2.0 V
0.26 0.35 0.50 A/V
5.0 10 13 kΩ
SERIAL PORT TIMING CONDITIONS
CHIP SELECT
A
E
CLOCK
C
D C D
DATA
A. Minimum CHIP SELECT setup time before CLOCK rising edge ...... 100 ns
B. Minimum CHIP SELECT hold time after CLOCK rising edge ........... 150 ns
C. Minimum DATA setup time before CLOCK rising edge .................... 150 ns
D. Minimum DATA hold time after CLOCK rising edge ........................ 150 ns
E. Minimum CLOCK low time before CHIP SELECT .............................. 50 ns
F. Maximum CLOCK frequency........................................................... 3.3 MHz
B
Dwg. WP-019
115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000
Loading...
+ 8 hidden pages
Buy Points How it Works FAQ Contact Us Questions and Suggestions Privacy Policy Cookie Policy Terms of Use