Datenblatt-pdf.com


A3907 Schematic ( PDF Datasheet ) - Allegro

Teilenummer A3907
Beschreibung Low Voltage Voice Coil Motor Driver
Hersteller Allegro
Logo Allegro Logo 




Gesamt 11 Seiten
A3907 Datasheet, Funktion
A3907
Low Voltage Voice Coil Motor Driver
Features and Benefits
WLCSP package for minimum footprint
Ramp control circuit
Fixed I2C logic thresholds
10-bit D-to-A converter
100 μA resolution
Low voltage I2C serial interface
Low current draw sleep mode-active low
2.3 to 5.5 V operation
Applications:
Camera focus motor
Description
Designed for linear control of small form factor voice coil
motors, theA3907 is capable of peak output currents to 102 mA
and operating voltages to 5.5 V.
Internal circuit protection includes thermal shutdown with
hysteresis, flyback clamp diode, and undervoltage monitoring
of VDD.
Package: 6-Bump Chip Scale Package
(suffix CG)
Functional Block Diagram
1.8 V
1.8 kΩ
1.8 kΩ
VDD
SDA
SCL
SLEEPZ
Bandgap
Ref
I2C Serial
Interface
10 Bit DAC
Control
Logic
Timer
2.3 to
5.5V
IOUT
1.2 Ω
GND
A3907-DS, Rev. 1






A3907 Datasheet, Funktion
A3907
Low Voltage Voice Coil Motor Driver
Example A
• The A3907 has been previously programmed to Level Con-
trol code 100 (11001002), for a target IOUT of 100 × 100 μA
= 10 mA (equation 1).
• The new target current level is 20 mA, so Level Control code
200 (110010002) is programmed (invert equation 1).
• For this example, the slew rate function selected is represented
by Ramp Control code 11002 : ramp, dual-subinterval, initial
subinterval delay factor 781 ns, second subinterval delay factor
50 μs.
• The A3907 determines the switchover point, T1, as follows:
CodeSwitchover = |(200 – 100)|/2 = 50 (equation 2),
T1 = 50 × 0.781 μs = 39 μs (equation 5),
IT1 = 50 + 100 × 100 μA = 150 μA (equation 6).
• The A3907 determines the target time final point, T2, as follows:
CodeSwitchover = |(200 – 100)|/2 = 50 (equation 2) ,
T2–T1 = 50 × 50 μs = 2.5 ms (equation 5).
Example B
• The A3907 has been previously programmed to Level Control
code 1000 (11111010002), for a target IOUT of 1000 × 100 μA
= 100 mA (equation 1).
Table 1. Slew Rate Function Table
Slew Rate
Method
Timer Bits Settings
T3 T2 T1 T0
0 00 0
Delay Factor
(μs)
tdT
0 (ramp feature disabled)
0 00 1
6.25
0 01 0
12.5
Single Interval
0
0
01
10
1
0
25
50
0 10 1
100
0 11 0
200
0 11 1
0 (ramp feature disabled)
T3 T2 T1 T0
1 00 0
tdT1
tdT2
0 (ramp feature disabled)
1 00 1
6.25
1 01 0
12.5
Dual Interval
1
1
01
10
1
0
0.781
25
50
1 10 1
100
1 11 0
200
1 11 1
0 (ramp feature disabled)
• The new target current level is 30 mA, so Level Control code
300 (1001011002) is programmed (invert equation 1).
• For this example, the slew rate function selected is represented
by Ramp Control code 11012 : ramp, dual-subinterval, initial
subinterval delay factor 781 ns, second subinterval delay factor
100 μs.
• The A3907 determines the switchover point, T2, as follows:
CodeSwitchover = |(1000 – 300)|/2 = 350 (equation 2),
T1 = 350 × 0.781 μs = 273 μs (equation 5),
IT1 = 350 + 300 × 100 μA = 65 μA (equation 6).
• The A3907 determines the target time final point, T1, as follows:
CodeSwitchover = |(1000 – 300)|/2 = 350 (equation 2) ,
T2–T1 = 350 × 100 μs = 35 ms (equation 5).
T0 T1
250
T2
25
200 20
150
Expanded Below
15
100 0
0.5 1.0 1.5 2.0 2.5 10
T1
15500
515
100
0
00..054 01.0.08
010
01..150 02.1.02 0.21.45
Time (ms)
Example A
T0 T1
1000
900
800
700
Expanded Below
600
500
400
300 0
8200
7100
5 10 15 20 25 30
T1
600
0
5 1 10 215 203 25 4 30
Time (ms)
Example B
T2
100
80
60
40
35
280
70
355 060
Figure 1. Examples of programmed IOUT change
Allegro MicroSystems, LLC
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
6

6 Page







SeitenGesamt 11 Seiten
PDF Download[ A3907 Schematic.PDF ]

Link teilen




Besondere Datenblatt

TeilenummerBeschreibungHersteller
A390SILICON RECTIFIERPowerex Power Semiconductors
Powerex Power Semiconductors
A3901Dual Full Bridge Low Voltage Motor DriverAllegro
Allegro
A3903Low Voltage DC Motor DriverAllegro Micro Systems
Allegro Micro Systems
A3904Low Voltage Voice Coil Motor DriverAllegro MicroSystems
Allegro MicroSystems
A3906Low Voltage Stepper and Single/Dual DC Motor DriverAllegro MicroSystems
Allegro MicroSystems

TeilenummerBeschreibungHersteller
CD40175BC

Hex D-Type Flip-Flop / Quad D-Type Flip-Flop.

Fairchild Semiconductor
Fairchild Semiconductor
KTD1146

EPITAXIAL PLANAR NPN TRANSISTOR.

KEC
KEC


www.Datenblatt-PDF.com       |      2020       |      Kontakt     |      Suche