Fairchild Semiconductor KA2822DTF, KA2822D, KA2822BDTF, KA2822BD Datasheet

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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)

Typical Application

•3.5-inch floppy disk drive (FDD) spildle motor

•Other 3-phase BLDC motor

Description

The KA2822D is a monolithic integrated circuit, and suitable for the three-phase spindle motor driver of FDD system.

28-SSOPH-375

Ordering Information

Device	Package	Operating Temp.
KA2822D	28-SSOPH-375	0 ~ 75°C
KA2822DTF	28-SSOPH-375	0 ~ 75°C
KA2822BD	28-SSOPH-375	0 ~ 75°C
KA2822BDTF	28-SSOPH-375	0 ~ 75°C

Rev. 1.0.1

May. 2000.

©2000 Fairchild Semiconductor International

1

KA2822D

Pin Assignments

FG INPUT(−)								FG INPUT(+)
				1	28
AGC				2	27			HALL BIAS
INDEX PULSE WIDTH				3	26			CURRENT DETECTION1
VOLTAGE REG				4	25			V INPUT(−)
INDEX BURST				5	24			V INPUT(+)
INDEX OUTPUT				6	23			U PHASE OUTPUT
				7	22			V PHASE OUTPUT
	CE

	FIN	KA2822D		FIN
SIGNAL GROUND		8	21		W PHASE OUTPUT
FG ZERO CROSS		9	20		NC
FG OUTPUT		10	19		U INPUT(+)
RPM SELECT		11	18		U INPUT(−)
CHARGE PUMP OUTPUT		12	17		CURRENT DETECTION2
OSC INPUT		13	16		VCC
NC		14	15		PHASE COMPENSATION

2

KA2822D

Pin Definitions

Pin Number	Pin Name	I/O	Pin Function Description
1	FG_INPUT	I	Negative input pin FG signal amp.
2	AGC	I	Automatic gain control input pin
3	INDEX PULSE WIDTH	O	Index pulse width detection (1.1V) pin
4	VOLTAGE REGULATOR	O	Voltage (2.2V) generator output pin
5	INDEX BURST	O	Index pulse width detection (1.4V) pin
6	INDEX OUTPUT	O	Index pulse output pin
7	CE	I	Chip enable (Active low)
8	SIGNAL GROUND	-	Signal ground
9	FG ZERO CROSS	O	FG signal zero cross detection pin
10	FG OUTPUT	O	FG signal output pin
11	RPM SELECT	I	RPM selection pin (L: 300, H: 360rpm)
12	CHARGE PUMP OUTPUT	O	Charge pump output pin
13	OSC INPUT	I	1MHz oscillation input pin
14	NC	-	No connection
15	PHASE COMPENSATION	I	Phase compensation cap. connection pin
16	VCC	-	5V power supply pin
17	CURRENT DETECTION2	I	Over current detection pin
18	U INPUT (−)	I	Negative input pin of U phase amp
19	U INPUT (+)	I	Positive input pin of U phase amp
20	NC	-	No connection
21	W PHASE OUTPUT	O	W phase output pin
22	V PHASE OUTPUT	O	V phase output pin
23	U PHASE OUTPUT	O	U phase output pin
24	U INPUT (+)	I	Positive input pin of V phase amp
25	V INPUT (−)	I	Negative input pin of V phase amp
26	CURRENT DETECTION1	I	Over current detection pin
27	HALL BIAS	I	Hall sensor bias input pin
28	FG INPUT (+)	I	Positive input pin of FG signal amp
FIN	POWER GROUND	-	Power ground

3

KA2822D

Internal Block Diagram

		VCC		CURRENT	CURRENT
				DETECTION2	DETECTION1
		16		17	26
U INPUT (+)	19	+
		U_AMP			U_OUT		23	U PHASE
U INPUT(−)	18	−						OUTPUT
V INPUT (+)	24	+	Output
		V_AMP					22
			Control		V_OUT			U PHASE
V INPUT(−)	25	−
								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			+
		FG_AMP					0.24V
FG INPUT(+)	28						15	PHASE
		+
								COMPENSATION
			FG
FG INPUT(−)	1	−	Zero-cross		−
							0.69V
					+
	10			BUF_AMP
FG OUTPUT
FG ZERO	9
CROSS
		Timing	Burst_time		Pulse_width		6	INDEX
		Detectpr	Circuit		Adjustment
								OUTPUT
VOLTAGE REG.	4						3	INDEX PULSE
		2.2V						WIDTH
INDEX BURST	5		Rpm_select	Speed	Charge		12
								CHARGE
			11_divider	Control	Pump
OSC INPUT	13							PUMP
		OSC
								OUTPUT
		14	11	8		20
		NC	RPM	SIGNAL	FIN	NC
			SELECT	GROUND

4

KA2822D

Equivalent Circuits

	U_amp, V_ amp input		U, V, W drive output and current detection 1, 2
	vcc					(17Pin,
						26Pin)
vcc		vcc				VCC
						(16Pin)
		5kΩ
2.5kΩ		2.5kΩ		U
					V
(19Pin,		(18Pin,		(23Pin)
					(22Pin)	W
25Pin)		24Pin)
						(21Pin)
			40kΩ	40kΩ	40kΩ
FG input and FG output				OSC input
	vcc					vcc
vcc	vcc
0.5kΩ	0.5kΩ			vcc
	(28Pin)			0.1kΩ
					1kΩ
	vcc		(13Pin)
					50pF
25kΩ		vcc
				5kΩ
		(10Pin)
	CE input		Hall bias input and voltage regulator output
				vcc	vcc
	vcc			vcc
	vcc					2.9V
			(27Pin)			vcc
CE	3kΩ
						(4Pin)
					2.2V
			5