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부품번호 | 8932-A 기능 |
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기능 | VOICE-COIL MOTOR DRIVER | ||
제조업체 | Allegro MicroSystems | ||
로고 | |||
전체 8 페이지수
8932-A
RET REF 1
28 RET SET
V FLT 2
V BEMF 3
GROUND 4
PROTECT
CIRCUIT
–
+
UV SET 5
R OUT P 6
OUT 7
SWITCH 8
IN N 9
OUTSW 10
RETRACT 11
–+
V REF – +
2V
27 VSENS
26 V LOAD
25 V SENS FB
24 SGND N
23 OUTP
VDD 22
LOAD
SUPPLY
21 OUT N
20 SGND P
19 ACT FB
18 PWR OFF
FAULT 12
MP RESET 13
PROTECT
CIRCUIT
SIGNAL
SUPPLY
14
V CC
17 H GAIN
+ 16 REFERENCE
– 15 ACT
Dwg. PP-042B
ABSOLUTE MAXIMUM RATINGS
Supply Voltages, VCC and VDD ............ 6.0 V
Output Current, IOUT (peak) ........... ±600 mA
(continuous) ........................... ±500 mA
Analog Input Voltage Range,
VIN .................................... -0.3 V to VCC
Logic Input Voltage Range,
VIN ............................... -0.3 V to +6.0 V
Package Power Dissipation,
PD ......................................... See Graph
Operating Temperature Range,
TA ..................................... 0°C to +70°C
Junction Temperature, TJ ............... +150°C†
Storage Temperature Range,
TS ................................ -55°C to +150°C
† Fault conditions that produce excessive junction
temperature will activate device thermal shutdown
circuitry. These conditions can be tolerated, but
should be avoided.
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.
VOICE-COIL MOTOR DRIVER
Providing control and drive of the voice-coil motor used for head
positioning in 5 V disk drive applications, the second-generation
A8932CLWA is a full-bridge driver that can be configured so that its
output current is a direct function of an externally applied control
voltage or current. This linear current control function is supplemented
by additional circuitry to protect the heads and the data disk during
system failure or normal system shutdown.
The two ±500 mA MOS driver outputs provide very low saturation
voltage and minimal power dissipation. Additional headroom is
achieved by the sense-FET structure eliminating the need for an exter-
nal current-sense resistor. Internal circuitry can be configured to
provide closed-loop velocity control of the actuator by utilizing the
generated back-EMF of the voice-coil motor. Thermal protection and
under-voltage lockout disables the system in a controlled sequence if a
fault condition occurs.
FEATURES
I
Class-B,
2
Ω
r
DS(on)
at
500
mA
Output
I Lossless Current Sensing
I Zero Current-Loop Deadband
I High Transconductance Bandwidth
I User-Adjustable Transconductance Gain
I Digital Transconductance Gain Switch (4:1 Ratio)
I 5 Volt Monitor with Selectable UV Trip Point
I Retract Circuitry Functional to 0 Volts
I Sleep Mode Function
I Internal Back-EMF Velocity Loop Option
I Internal Thermal Shutdown Circuitry
Always order by complete part number, e.g., A8932CLWA .
8932-A
VOICE-COIL MOTOR DRIVER
ELoLaEdC=TR1I5C0AµLHC/3H.5AΩRA(uCnTlEesRsISoTthICeSrwaitsTeAn=ot+e2d5)°.C, VCC = VDD = 5.0 V, VREF = VIN = 2.0 V,
Characteristic
Miscellaneous
Supply Voltage
Under-Voltage Lockout Voltage
Fault Logic Output
Power-On Reset
Total Supply Current
Logic Input Voltage
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
Symbol
Test Conditions
VCC
VDD
VCC
VFAULT
IFAULT
VMPRESET
ICC + IDD
VIN(0)
VIN(1)
TJ
∆TJ
Operating
Operating
VCC = VDD
VRETRACT ≥ 3.5 V
VRETRACT ≤ 0.7 V
VFLT = 2.25 V
VRETRACT ≥ 3.5 V
VRETRACT ≤ 0.7 V, IMPREST = 1.5 mA
Outputs Balanced, No Load
Sleep Mode, PWR OFF = VCC
Min.
Limits
Typ. Max.
Units
4.5 5.0 5.5
V
4.5 5.0 5.5
V
3.9 4.2 4.35 V
— — 500 mV
4.5 —
—
V
— >20 —
µA
4.5 —
—
V
— — 800 mV
— — 10 mA
— — 2.0 mA
— — 0.7 V
3.5 —
—
V
— 165 —
°C
— 20 — °C
Negative current is defined as coming out of (sourcing) the specified device terminal.
Typical Data is for design information only.
The products described here are manufactured under one or more
U.S. patents or U.S. patents pending.
Allegro MicroSystems, Inc. reserves the right to make, from time to
time, such departures from the detail specifications as may be required
to permit improvements in the performance, reliability, or
manufacturability of its products. Before placing an order, the user is
cautioned to verify that the information being relied upon is current.
Allegro products are not authorized for use as critical components
in life-support devices or systems without express written approval.
The information included herein is believed to be accurate and
reliable. However, Allegro MicroSystems, Inc. assumes no responsi-
bility for its use; nor for any infringement of patents or other rights of
third parties which may result from its use.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
4페이지 8932-A
VOICE-COIL MOTOR DRIVER
Retract and Brake. A retract-brake sequence is initiated
on receiving a fault indication from the internal thermal
shutdown (TSD), or under-voltage lockout (UVLO), or an
externally applied logic High at the RETRACT input.
If the velocity control scheme is implemented, the
head can be retracted under the full control of VIN in
conjunction with OUTSW back-EMF voltage if no fault
condition exists. If a fault condition were to occur how-
ever, the retract velocity would be controlled by applying a
constant user-defined voltage across the load:
2R
VRET-SET
=
1000
+
8
R7
+
R8
(Equation 3)
where
R
7
+
R
8
>>
1000
Ω.
When the sequence is operated, the output voltage is
forced to approximately VRET-SET to retract the heads, and
then a fault command (“brake”) is sent to the spindle
motor driver. The user determines the total time for the
retract sequence, before the spindle brake is enabled, by
the choice of an external resistor and capacitor at the
FAULT output.
Power for the retract function is provided by the
rectified back EMF of the spindle motor by way of the VBEMF
terminal. The A8932CLWA will perform the retract func-
tion under low supply conditions (nominally down to 2 V).
Operation down to almost 0 V requires an energy-storage
capacitor at the VFLT terminal.
Protective Features. The A8932CLWA has a number of
protective features incorporated into the design. Under-
voltage lockout provides system protection in the event of
reduced primary supply voltages. The under-voltage trip
point is internally set at approximately 4.2 V. It can be
user-defined with an external resistor voltage divider:
2 (R + R )
UVTRIP =
56
R6
where R5 + R6 << 200 kΩ.
(Equation 4)
Thermal shutdown circuitry is included to protect the
device from excessive junction temperature. It is only
intended to protect the chip from catastrophic failures due
to excessive junction temperature.
TEST CIRCUIT AND TYPICAL APPLICATION
RZ
VIN Rgm
V REF = 2 V
CZ
X
H GAIN
PWR OFF
R FAUL≥T 200 kΩ
ERROR
– AMP
+
+5 V
V CC
VDD
I SENSE +
POWER
AMP
+
VOLTAGE-SENSE
AMP
–
+
V REF
VOICE COIL
MOTOR
2V –
POWER
CONTROL
LOGIC
TSD
CURRENT-SENSE
AMP
I SENSE –
–
V REF
+
RS
R3
R2
C2
V CC
PROTECTION
CIRCUITRY
R5
R6
RETRACT
CONTROL
VREF
–
+
R7
R8
C1
R1
R Vgm
X
SWITCH
BACK EMF FROM
SPINDLE MOTOR
VDD
DIODE FOR RETRACT FUNCTION
OTHERWISE SHORT TO SUPPLY
Dwg. EP-041D
www.allegromicro.com
7페이지 | |||
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구매 문의 | 일반 IC 문의 : 샘플 및 소량 구매 ----------------------------------------------------------------------- IGBT, TR 모듈, SCR 및 다이오드 모듈을 포함한 광범위한 전력 반도체를 판매합니다. 전력 반도체 전문업체 상호 : 아이지 인터내셔날 사이트 방문 : [ 홈페이지 ] [ 블로그 1 ] [ 블로그 2 ] |
부품번호 | 상세설명 및 기능 | 제조사 |
8932-A | VOICE-COIL MOTOR DRIVER | Allegro MicroSystems |
DataSheet.kr | 2020 | 연락처 | 링크모음 | 검색 | 사이트맵 |