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KA2822D
3-Phase BLDC Motor Driver
Features
• 3-phase, full-wave, linear BLDC motor driver
with 2 hall sensors
• Built-in soft switching drive circuit
• 300 or 360 RPM speed control
• Snubberless
• Built-in chip enable function
• Built-in digital speed control circuit
• Built-in current limit circuit
• Index sensorless
• Built-in TSD (Thermal shutdown)
• Low saturation voltage
• Digital input: TTL, 5V CMOS compatible
• Built-in current-mode control circuit (I
PEAK
: 1A)
Description
The KA2822D is a monolithic integrated circuit, and suit-
able for the three-phase spindle motor driver of FDD system.
28-SSOPH-375
Typical Application
• 3.5-inch floppy disk drive (FDD) spildle motor
• Other 3-phase BLDC motor
Ordering Information
Device
KA2822D
KA2822BD
Package
28-SSOPH-375
28-SSOPH-375
Operating Temp.
0 ~ 75°C
0 ~ 75°C
0 ~ 75°C
0 ~ 75°C
KA2822DTF 28-SSOPH-375
KA2822BDTF 28-SSOPH-375
Rev. 1.0.1
May. 2000.
©2000 Fairchild Semiconductor International
1
KA2822D
Pin Assignments
FG INPUT(−)
AGC
INDEX PULSE WIDTH
VOLTAGE REG
INDEX BURST
INDEX OUTPUT
CE
1
2
3
4
5
6
7
28
27
26
25
24
23
22
FG INPUT(+)
HALL BIAS
CURRENT DETECTION1
V INPUT(−)
V INPUT(+)
U PHASE OUTPUT
V PHASE OUTPUT
FIN
KA2822D
FIN
SIGNAL GROUND
FG ZERO CROSS
FG OUTPUT
RPM SELECT
CHARGE PUMP OUTPUT
OSC INPUT
NC
8
9
10
11
12
13
14
21
20
19
18
17
16
15
W PHASE OUTPUT
NC
U INPUT(+)
U INPUT(−)
CURRENT DETECTION2
V
CC
PHASE COMPENSATION
2
KA2822D
Pin Definitions
Pin Number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
FIN
Pin Name
FG_INPUT
AGC
INDEX PULSE WIDTH
VOLTAGE REGULATOR
INDEX BURST
INDEX OUTPUT
CE
SIGNAL GROUND
FG ZERO CROSS
FG OUTPUT
RPM SELECT
CHARGE PUMP OUTPUT
OSC INPUT
NC
PHASE COMPENSATION
V
CC
CURRENT DETECTION2
U INPUT (−)
U INPUT (+)
NC
W PHASE OUTPUT
V PHASE OUTPUT
U PHASE OUTPUT
U INPUT (+)
V INPUT (−)
CURRENT DETECTION1
HALL BIAS
FG INPUT (+)
POWER GROUND
I/O
I
I
O
O
O
O
I
-
O
O
I
O
I
-
I
-
I
I
I
-
O
O
O
I
I
I
I
I
-
Pin Function Description
Negative input pin FG signal amp.
Automatic gain control input pin
Index pulse width detection (1.1V) pin
Voltage (2.2V) generator output pin
Index pulse width detection (1.4V) pin
Index pulse output pin
Chip enable (Active low)
Signal ground
FG signal zero cross detection pin
FG signal output pin
RPM selection pin (L: 300, H: 360rpm)
Charge pump output pin
1MHz oscillation input pin
No connection
Phase compensation cap. connection pin
5V power supply pin
Over current detection pin
Negative input pin of U phase amp
Positive input pin of U phase amp
No connection
W phase output pin
V phase output pin
U phase output pin
Positive input pin of V phase amp
Negative input pin of V phase amp
Over current detection pin
Hall sensor bias input pin
Positive input pin of FG signal amp
Power ground
3
KA2822D
Internal Block Diagram
CURRENT
CURRENT
DETECTION2 DETECTION1
17
26
V
CC
16
U INPUT (+) 19
U INPUT(−) 18
V INPUT (+) 24
V INPUT(−) 25
+
U_AMP
−
+
V_AMP
−
U_OUT
23
U PHASE
OUTPUT
Output
Control
V_OUT
22
U PHASE
OUTPUT
AGC
2
AGC
W_OUT
21
W PHASE
OUTPUT
HALL BIAS 27
Start-up
Hall
Zero-cross
TSD
CE
7
CE
CON_AMP
1.3V
−
+
0.24V
15
FG
Zero-cross
−
0.69V
BUF_AMP
+
PHASE
COMPENSATION
FG INPUT(+) 28
FG INPUT(−)
1
FG_AMP
+
−
FG OUTPUT 10
FG ZERO
CROSS
9
Timing
Detectpr
Burst_time
Circuit
Pulse_width
Adjustment
6
INDEX
OUTPUT
INDEX PULSE
WIDTH
CHARGE
PUMP
OUTPUT
VOLTAGE REG.
INDEX BURST
4
2.2V
5
OSC
Rpm_select
11_divider
Speed
Control
Charge
Pump
3
12
OSC INPUT 13
14
NC
11
RPM
SELECT
8
SIGNAL
GROUND
FIN
20
NC
4
KA2822D
Equivalent Circuits
U_amp, V_ amp input
U, V, W drive output and current detection 1, 2
vcc
(17Pin,
26Pin)
vcc
vcc
5kΩ
2.5kΩ
2.5kΩ
(18Pin,
24Pin)
40kΩ
U
(23Pin)
V
(22Pin)
V
CC
(16Pin)
(19Pin,
25Pin)
W
(21Pin)
40kΩ
40kΩ
FG input and FG output
OSC input
vcc
vcc
0.5kΩ
0.5kΩ
(28Pin)
0.1kΩ
1kΩ
50pF
5kΩ
vcc
vcc
vcc
(13Pin)
vcc
25kΩ
vcc
(10Pin)
CE input
Hall bias input and voltage regulator output
vcc
vcc
vcc
CE
3kΩ
vcc
2.9V
vcc
(27Pin)
vcc
(4Pin)
2.2V
5
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