ST L6590 User Manual

L6590

FULLY INTEGRATED POWER SUPPLY

■WIDE-RANGE MAINS OPERATION

■"ON-CHIP" 700V V(BR)DSS POWER MOS

■65 kHz INTERNAL OSCILLATOR

■2.5V ± 2% INTERNAL REFERENCE

■STANDBY MODE FOR HIGH EFFICIENCY AT LIGHT LOAD

■OVERCURRENT AND LATCHED OVERVOLTAGE PROTECTION

■NON DISSIPATIVE BUILT-IN START-UP CIRCUIT

■THERMAL SHUTDOWN WITH HYSTERESIS

■BROWNOUT PROTECTION (SMD PACKAGE ONLY)

MAIN APPLICATIONS

■WALL PLUG POWER SUPPLIES UP TO 15 W

■AC-DC ADAPTERS

■AUXILIARY POWER SUPPLIES FOR:

-CRT AND LCD MONITOR (BLUE ANGEL)

-DESKTOP PC/SERVER

-FAX, TV, LASER PRINTER

MINIDIP	SO16W
ORDERING NUMBERS:
L6590N	L6590D

- HOME APPLIANCES/LIGHTING

■LINE CARD, DC-DC CONVERTERS

DESCRIPTION

The L6590 is a monolithic switching regulator designed in BCD OFF-LINE technology, able to operate with wide range input voltage and to deliver up to 15W output power. The internal power switch is a lat-

eral power MOSFET with a typical RDS(on) of 13Ω and a V(BR)DSS of 700V minimum.

TYPICAL APPLICATION CIRCUIT

AC line		Pout	AC line				Pout
88 to 264 Vac		up to 15W	88 to 264 Vac				up to 15W
	DRAIN				DRAIN
	1					1
	L6590	Vcc			L6590		Vcc
		3					3
6, 7, 8	4	5		6, 7, 8	5		4
GND	COMP	VFB		GND	VFB	COMP
Primary Feedback				Secondary Feedback
October 2000							1/23

L6590

DESCRIPTION (continued)

The MOSFET is source-grounded, thus it is possible to build flyback, boost and forward converters.

The device can work with secondary feedback and a 2.5V±2% internal reference, in addition to a high gain error amplifier, makes possible also the use in applications either with primary feedback or not isolated.

The internal fixed oscillator frequency and the integrated non dissipative start-up generator minimize the external component count and power consumption.

The device is equipped with a standby function that automatically reduces the oscillator frequency from 65 to 22 kHz under light load conditions to enhance

BLOCK DIAGRAM

efficiency (Pin < 1W @ Pout = 0.5W with wide range mains).

Internal protections like cycle-by-cycle current limiting, latched output overvoltage protection, mains undervoltage protection (SMD version only) and thermal shutdown generate a 'robust' design solution.

The IC uses a special leadframe with the ground pins (6, 7 and 8 in minidip, 9 to16 in SO16W package) internally connected in order for heat to be easily removed from the silicon die. An heatsink can then be realized by simply making provision of few cm2 of copper on the PCB. Furthermore, the pin(s) close to the high-voltage one are not connected to ease compliance with safety distances on the PCB.

	DRAIN				[x] : L6590D (SO16W)
	(1) [1]
	START-UP
							VCC
					VREF		(3) [4]
	THERMAL		SUPPLY
			& UVLO
	SHUTDOWN
					+
					-		SGND
					OVP	VREF
							[5]
					BROWNOUT
	+					+	BOK
	-					-
GND		OCP					[6]
						2.5V
(6,7,8)				PWM
PGND	STANDBY						VFB
[9, ..., 16]						-
			OSC				(5) [8]
			65/22 kHz			+
						2.5V
					COMP
					(4) [7]

PIN CONNECTIONS (Top view)

DRAIN

PGND

DRAIN

GND

N.C.

PGND

N.C.

PGND

N.C.

GND

Vcc

PGND

Vcc

GND

SGND

PGND

COMP

VFB

BOK

PGND

COMP

PGND

MINIDIP

VFB

PGND

L6590

SO16W

L6590D

2/23

			L6590
PIN FUNCTIONS
Pin#		Name	Description
L6590	L6590D
1	1	DRAIN	Drain connection of the internal power MOSFET. The internal high voltage start-up
			generator sinks current from this pin.
2	2, 3	N.C.	Not internally connected. Provision for clearance on the PCB.
3	4	VCC	Supply pin of the IC. An electrolytic capacitor is connected between this pin and ground.
			The internal start-up generator charges the capacitor until the voltage reaches the start-
			up threshold. The PWM is stopped if the voltage at the pin exceeds a certain value.
4	7	COMP	Output of the Error Amplifier. Used for control loop compensation or to directly control
			PWM with an optocoupler.
5	8	VFB	Inverting input of the Error Amplifier. The non-inverting one is internally connected to a
			2.5V± 2% reference. This pin can be grounded in some feedback schemes.
6 to 8	-	GND	Connection of both the source of the internal MOSFET and the return of the bias current
			of the IC. Pins connected to the metal frame to facilitate heat dissipation.
-	6	BOK	Brownout Protection. If the voltage applied to this pin is lower than 2.5V the PWM is
			disabled. This pin is typically used for sensing the input voltage of the converter through
			a resistor divider. If not used, the pin can be either left floating or connected to Vcc
			through a 15 kΩ resistor.
-	5	SGND	Current return for the bias current of the IC.
-	9 to 16	PGND	Connection of the source of the internal MOSFET. Pins connected to the metal frame to
			facilitate heat dissipation.

THERMAL DATA

Symbol	Parameter	Minidip	SO16W	Unit
Rthj-amb	Thermal Resistance Junction to ambient (*)	35 to 60	40 to 65	°C/W
Rthj-pins	Thermal Resistance Junction to pins	15	20	°C/W

(*) Value depending on PCB copper area and thickness.

ABSOLUTE MAXIMUM RATINGS

Symbol	Parameter	Value	Unit
Vds	Drain Source Voltage	-0.3 to 700	V
Id	Drain Current	0.7	A
Vcc	IC Supply Voltage	18	V
Iclamp	Vcc Zener Current	20	mA
	Error Amplifier Ouput Sink Current	3	mA
	Voltage on Feedback Input	5	V
	BOK pin Sink Current	1	mA
Ptot	Power Dissipation at Tamb < 50°C (Minidip and SO16W)	1.5	W
	3 cm2, 2 oz copper dissipating area on PCB
Tj	Operating Junction Temperature	-40 to 150	°C
Tstg	Storage Temperature	-40 to 150	°C

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L6590

ELECTRICAL CHARACTERISTCS (Tj = -25 to 125°C, Vcc = 10V; unless otherwise specified)

Symbol	Parameter	Test Condition	Min.	Typ.	Max.	Unit
POWER SECTION
V(BR)DSS	Drain Source Voltage	Id < 200 µA; Tj = 25 °C	700			V
Idss	Off state drain current	Vds = 560V; Tj = 125 °C			200	µA
RDS(on)	Drain-to-Source on resistance	Id = 120mA; Tj = 25 °C		13	16	Ω
	RDS(on) vs. Tj: see fig. 20
		Id = 120mA; Tj = 125 °C		23	28
ERROR AMP SECTION
VFB	Input Voltage	Tj = 25 °C	2.45	2.5	2.55	V
		Tj = 125°C	2.4	2.5	2.6
Ib	E/A Input Bias Current	VFB = 0 to 2.5 V		0.3	5	µA
Avol	DC Gain	open loop	60	70		dB
B	Unity Gain Bandwidth		0.7	1		MHz
SVR	Supply voltage Rejection	f = 120 Hz		70		dB
Isink	Output Sink Current	VCOMP = 1V		1		mA
Isource	Output Source Current	VCOMP = 3.5V; VFB = 2V	-0.5	-1	-2.5	mA
VCOMPH	Vout High	Isource = -0.5mA; VFB=2V	3.8	4.50		V
VCOMPL	Vout Low	Isink = 1mA ; VFB=3V			1	V
OSCILLATOR SECTION
Fosc	Oscillator Frequency	Tj = 25 °C	58	65	72	kHz
			52	65	74
Dmin	Min. Duty Cycle	VCOMP = 1V			0	%
Dmax	Max. Duty Cycle	VCOMP = 4V	67	70	73	%
DEVICE OPERATION SECTION
Iop	Operating Supply Current	fsw = Fosc		4.5	7	mA
IQ	Quiescent Current	MOS disabled		3.5	6	mA
Icharge	VCC charge Current	Vcc = 0V to Vccon - 0.5V;	-3	-4.5	-7	mA
		Vds = 100 to 400V; Tj = 25°C
		Vcc = 0V to Vccon - 0.5V;	-2.5	-4.5	-7.5	mA
		Vds = 100 to 400V
VCCclamp	VCC clamp Voltage	Iclamp = 10mA (*)	16.5	17	17.5	V
Vccon	Start Threshold	(*)	14	14.5	15	V
	voltage
Vccoff	Min operating voltage after Turn	(*)	6	6.5	7	V
	on
Vdsmin	Drain start voltage				40	V
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						L6590
ELECTRICAL CHARACTERISTICS (continued)
Symbol	Parameter	Test Condition	Min.	Typ.	Max.	Unit
CIRCUIT PROTECTIONS
Ipklim	Pulse-by-pulse Current Limit	di/dt = 120 mA/ µs	550	625	700	mA
OVP	Overvoltage Protection	Icc = 10 mA (*)	16	16.5	17	V
LEB	Masking Time	After MOSFET turn-on (**)		120		ns
STANDBY SECTION
FSB	Oscillator Frequency		19	22	25	kHz
Ipksb	Peak switch current for Standby	Transition from Fosc to FSB		80		mA
	Operation
Ipkno	Peak switch current for Normal	Transition from FSB to Fosc		190		mA
	Operation
BROWNOUT PROTECTION (L6590D only)
Vth	Threshold Voltage	Voltage either rising or falling	2.4	2.5	2.6	V
IHys	Current Hysteresis	Vpin = 3V	-30	-50	-70	µA
VCL	Clamp Voltage	Ipin = 0.5 mA	5.6	6.4	7.2	V
THERMAL SHUTDOWN (***)
	Threshold		150	165		°C
	Hysteresis			40		°C
(*) Parameters tracking one the other

(**) Parameter guaranteed by design, not tested in production

(***) Parameters guaranteed by design, functionality tested in production

Figure 1. Start-up & UVLO Thresholds

Vcc [V]

16

14
	Start-up

12

10

8					UVLO
6
			0	50	100	150
-50

Tj [°C]

Figure 2. Start-up Current Generator

Icc [mA]

5.5
5			Vdrain = 40 V
					Tj = -25 °C
4.5					Tj = 25 °C
4
3.5
					Tj = 125 °C
3	2	4	6	8	10	12
0

Vcc [V]

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L6590

Figure 3. Start-up Current Generator	Figure 6. IC Operating Current
Icc [mA]	Icc [mA]

5.5							5
			Vdrain = 60 V		Tj = -25 °C			VFB = 2.3 V						Tj = 125 °C
5								fsw = 65 kHz
							4.5
					Tj = 25 °C									Tj = 25 °C
4.5
							4							Tj = -25 °C
4					Tj = 125 °C
3.5							3.5
3	2	4	6	8	10	12	3	8	9	10	11	12	13	14	15
0							7
			Vcc [V]								Vcc [V]

Figure 4. IC Consumption Before Start-up

Figure 7. IC Operating Current

Icc [µA]									Icc [mA]
700									4.4
										VFB = 2.3 V
					Tj = -25 °C
600									4.2	fsw = 22 kHz					Tj = 125 °C
500									4						Tj = 25 °C
400							Tj = 25 °C		3.8
															Tj = -25 °C
									3.6
	Tj = 125 °C
300
									3.4
200									3.2
100	8	9	10	11	12	13	14	15	3	8	9	10	11	12	13	14	15
7									7
				Vcc [V]									Vcc [V]

Figure 5. IC Quiescent Current

Figure 8. Switching Frequency vs.

Icc [mA]							Temperature
4						fsw [kHz]
	VFB = 2.7 V				Tj = 25 °C	80
3.8						70		Normal operation
3.6						60
						50
3.4	Tj = 125 °C					40
3.2	Tj = -25 °C					30		Standby
3						20
	8	10	12	14	16	18
6
			Vcc [V]			10	0	50	100	150
						-50

Tj [°C]

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L6590

Figure 9. Vcc clamp vs. Temperature

Figure 12. OCP threshold vs. Temperature

VCCclamp [V]					Ipklim / (Ipklim @ Tj = 25°C)
18					1.1
17.8					1.08		di/dt = 120 mA/µs
17.6					1.06
			Iclamp = 20 mA
					1.04
17.4					1.02
			Iclamp = 10 mA
17.2					1
17	0	50	100	150	0.98	0	50	100	150
-50					-50
		Tj [°C]					Tj [°C]

Figure 10. OVP Threshold vs. Temperature

Figure 13. Internal E/A Reference Voltage

Vth [V]					Vref [V]
16					2.6
15.8					2.55
15.6
					2.5
15.4
15.2					2.45
15	0	50	100	150	2.4	0	50	100	150
-50					-50
		Tj [°C]					Tj [°C]

Figure 11. OCP Threshold vs. Current Slope

Figure 14. Error Amplifier Slew Rate

Ipklim / (Ipklim @ di/dt = 120 mA/µs)					VCOMP [V]
1.06					5
1.04		Tj = 25 °C			4	VCOMP					RL = 10 kΩ
											CL = 100 pF
												open loop
1.02					3	VFB
1					2
0.98					1
0.96	100	150	200	250	0	2	4	6	8	10	12	14	16
50					0
		dI/dt [mA/µs]							t [µs]

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