ST L6590 User Manual

FULLY INTEGRATED POWER SUPPL Y

■ WIDE-RANGE MAINS OPERATION

■ "ON-CHIP" 700V V (BR)DSS POWER MOS

■ 65 kHz INTERNAL OSCILLA TOR

■ 2.5V ± 2% INTERNAL REFERENCE

■ STANDBY MODEFOR HIGH EFFICIENCY AT

LIGHT LOAD

■ OVERCURRENT AND LATCHED

OVERVOLTAGE PROTECTION

■

NON DISSIPATIVE BUILT-IN START-UP CIRCUIT

■ THERMAL SHUTDOWN WITH HYSTERESIS

■ BROWNOUTPROTECTION (SMD PACKAGE

ONLY)

L6590

MINIDIP SO16W

ORDERING NUMBERS:

L6590N L6590D

- HOME APPLIANCES/LIGHTING

■ LINE CARD, DC-DC CONVERTERS

MAIN APPLICATIONS

■ WALL PLUG POWER SUPPLIES UP TO 15 W

■ AC-DC ADAPTERS

■ AUXILIARYPOWER SUPPLIES FOR:

- CRT AND LCD MONITOR (BLUE ANG EL)

- DESKTOP PC/SERVER

- FAX, TV, LASER PRINTER

TYPICAL APPLICATION CIRCUIT

AC line

88 to 264 Vac

GND

DRAIN

L6590

1

Vcc

3

56, 7,8

4

VFBCOMP

Pout

up to 15W

DESCRIPTION

The L6590 is a monolithic switching regulator de­signed in BCD OFF-LINEtechnology, able to operate
with wide range input voltage and to deliver up to
15Woutput power. The internal power switch is a lat­eral power MOSFET with a typical R
and a V

AC line

88 to 264 Vac

(BR)DSS

of 700V minimum.

DRAIN

1

GND

L6590

VFB COMP

3

56, 7, 8

4

Vcc

DS(on)

of 13

Pout

up to 15W

Ω

October 2000

Primary Feedback

Secondary Feedback

1/23

L6590

D

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.

Theinternalfixedoscillator frequencyandthe 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

DRAIN

(1)

[1]

START-UP

THERMAL

SHUTDOWN

+

-

GND

(6,7,8)

PGND

[9, ..., 16]

OCP

STANDBY

65/22kHz

efficiency (P

<1W@P

in

= 0.5W with wide range

out

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.

TheIC usesa 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 cm
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.

[x] : L6590D (SO16W)

CC

V

(3)

SGN

[5]

BOK

[6]

VFB

(5)

[4]

[8]

OSC

SUPPLY

&UVLO

PWM

VREF

+

-

OVP

BROWNOUT

VREF

+

-

­+

2.5V

2.5V

2

of

PIN CONNECTIONS

DRAIN

COMP

2/23

(Top view)

N.C.

Vcc

MINIDIP

L6590

GND
GND
GND
VFB

DRAIN

N.C.
N.C.

Vcc

SGND

BOK

COMP

VFB

COMP

[7]

(4)

PGND
PGND
PGND
PGND
PGND
PGND
PGND
PGND

SO16W
L6590D

L6590

PIN FUNCTIONS

Pin#

L6590 L6590D

1 1 DRAIN Drain connection of the internal power MOSFET. The internal high voltage start-up

2 2, 3 N.C. Not internally connected. Provision for clearance on the PCB.
34V

47

5 8 VFB Inverting input of the Error Amplifier.The non-inverting one is internally connected to a

6 to 8 - GND Connection of both the source of the internal MOSFET and the return of the bias current

- 6 BOK Brownout Protection. If the voltage applied to this pin is lower than 2.5V the PWM is

- 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

Name Description

generator sinks current from this pin.

Supply pin of the IC. An electrolytic capacitor is connected between this pin and ground.

CC

The internal start-up generator charges the capacitor until the voltage reaches the start­up threshold. The PWM is stopped if the voltage at the pin exceeds a certain value.

COMP

Output of the Error Amplifier. Used for control loop compensation or to directly control
PWM with an optocoupler.

2.5V± 2% reference. This pin can be grounded in some feedback schemes.

of the IC. Pins connected to the metal frame to facilitate heat dissipation.

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.

facilitate heat dissipation.

THERMAL DATA

Symbol Parameter Minidip SO16W Unit

R

thj-amb

R

thj-pins

(*) Value depending on PCB copper area and thickness

Thermal Resistance Junction to ambient (*) 35 to 60 40 to 65 °C/W
Thermal Resistance Junction to pins 15 20 °C/W

.

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

I

V

I

clamp

P

T

T

stg

ds
d
cc

tot

Drain Source Voltage -0.3 to 700 V
Drain Current 0.7 A
IC Supply Voltage 18 V
VccZener Current 20 mA
Error Amplifier Ouput Sink Current 3 mA
Voltage on Feedback Input 5 V
BOK pin Sink Current 1 mA
Power Dissipation at T

2

, 2 oz copper dissipating area on PCB

3cm
Operating Junction Temperature -40 to 150 °C

j

< 50°C (Minidip and SO16W)

amb

1.5 W

Storage Temperature -40 to 150 °C

3/23

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

I

R

DS(on)

Drain Source Voltage Id< 200 µA; Tj= 25 °C 700 V
Off state drain current Vds= 560V; Tj= 125 °C 200 µA

dss

Drain-to-Source on resistance
R

vs. Tj: see fig. 20

DS(on)

I

= 120mA; Tj=25°C 13 16 Ω

d

= 120mA; Tj= 125 °C 23 28

I

d

ERROR AMP SECTION

V

Input Voltage Tj= 25 °C 2.45 2.5 2.55 V

FB

= 125°C 2.4 2.5 2.6

T

j

Ib E/A Input Bias Current V

= 0 to 2.5 V 0.3 5 µA

FB

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

I

I

source

Output Sink Current V

sink

Output Source Current V

=1V 1 mA

COMP

= 3.5V; VFB = 2V -0.5 -1 -2.5 mA

COMP

V

COMPH

V

COMPL

Vout High I
Vout Low I

OSCILLATOR SECTION

F

D

D

Oscillator Frequency Tj=25°C 58 65 72 kHz

osc

Min. Duty Cycle V

min

Max. Duty Cycle V

max

DEVICE OPERATION SECTION

I

I

chargeVCC

V

CCclampVCC

V

Operating Supply Current fsw = Fosc 4.5 7 mA

op

I

Quiescent Current MOS disabled 3.5 6 mA

Q

charge Current Vcc=0VtoV

clamp Voltage I

Start Threshold

ccon

voltage

= -0.5mA; VFB=2V 3.8 4.50 V

source

= 1mA ; VFB=3V 1 V

sink

52 65 74

=1V 0 %

COMP

=4V 67 70 73 %

COMP

- 0.5V;

V

= 100 to 400V; Tj=25°C

ds

=0VtoV

V

cc

ccon

ccon

- 0.5V;

-3 -4.5 -7 mA

-2.5 -4.5 -7.5 mA

Vds= 100 to 400V

= 10mA (*) 16.5 17 17.5 V

clamp

(*) 14 14.5 15 V

V

4/23

V

ccoff

dsmin

Min operating voltage after Turnon(*) 6 6.5 7 V

Drain start voltage 40 V

L6590

ELECTRICAL CHARACTERISTICS

(continued)

Symbol Parameter Test Condition Min. Typ. Max. Unit

CIRCUIT PROTECTIONS

I

pklim

OVP Overvoltage Protection I

Pulse-by-pulse Current Limit di/dt = 120 mA/ µs 550 625 700 mA

= 10 mA (*) 16 16.5 17 V

cc

LEB Masking Time After MOSFET turn-on (**) 120 ns

STANDBY SECTION

F

I

pksb

Oscillator Frequency 19 22 25 kHz

SB

Peak switch current for Standby

Transition from F

osc

to F

SB

80 mA

Operation

I

pkno

Peak switch current for Normal

Transition from FSBto F

osc

190 mA

Operation

BROWNOUT PROTECTION (L6590D only)

V
I
V

Threshold Voltage Voltage either rising or falling 2.4 2.5 2.6 V

th

Current Hysteresis V

Hys

Clamp Voltage I

CL

= 3V -30 -50 -70 µA

pin

= 0.5 mA 5.6 6.4 7.2 V

pin

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 Figure 2. Start-up Current Generator

Vcc [V]

16

14

Start-up

12

10

8

6

-50 0 50 100 150

Tj [°C]

UVLO

Icc [mA]

5.5

5

Vdrain = 40 V

4.5

4

3.5

3

024681012

Vcc [V]

Tj = -25°C

Tj = 25 °C

Tj = 125 °C

5/23

L6590

Figure 3 . Start-up Current Generator

Icc [mA]

5.5

Vdrain = 60 V

Tj = -25 °C

5

Tj = 25°C

4.5

4

Tj = 125°C

3.5

3

024681012

Vcc [V]

Figure 4. IC Consumption Before Start-up

Icc [µA]

700

600

500

400

300

200

Tj = 125°C

Tj = -25 °C

Tj = 25 °C

Figure 6. IC Operating Current

Icc [mA]

5

VFB = 2.3 V
fsw = 65 kHz

4.5

4

Tj = 125°C

Tj = 25 °C

Tj = -25°C

3.5

3

7 8 9 10 11 12 13 14 15

Vcc [V]

Figure 7. IC Operating Current

Icc [mA]

4.4

VFB = 2.3 V

4.2
4

3.8

3.6

3.4

3.2

fsw = 22 kHz

Tj = 125 °C

Tj = 25 °C

Tj = -25°C

100

7 8 9 101112131415

Vcc [V]

Figure 5. IC Quiescent Current

Icc [mA]

4

VFB = 2.7 V

3.8

3.6

3.4

Tj = 125°C

Tj = -25°C

3.2

3

6 8 10 12 14 16 18

Vcc [V]

6/23

Tj = 25°C

3

7 8 9 10 11 12 13 14 15

Vcc [V]

Figure 8. S witching Frequency vs.

Temperature

fsw [kHz]

80
70
60
50
40
30
20
10

-50 0 50 100 150

Normal operation

Standby

Tj [°C]

L6590

Figure 9 . Vcc clamp vs. Temperature

VCCclamp [V]

18

17.8

17.6

I

clamp

=20mA

17.4

Iclamp =10mA

17.2

17

-50 0 50 100 150

Tj [°C]

Figure 10. OV P Threshold vs. Temperature

Vth [V]

16

15.8

15.6

15.4

Figure 12. OCP threshold vs. Temperat ure

Ipklim / (Ipklim@ Tj = 25°C)

1.1

1.08

di/dt = 120 mA/µs

1.06

1.04

1.02

1

0.98

-50 0 50 100 150

Tj [°C]

Figure 13. Internal E/A Referenc e Voltage

Vref [V]

2.6

2.55

2.5

15.2

15

-50 0 50 100 150

Tj [°C]

Figure 11. OCP Threshold vs. Current Slope

Ipklim / (Ipklim @ di/dt = 120 mA/µs)

1.06

1.04

1.02

1

0.98

0.96
50 100 150 200 250

Tj = 25°C

dI/dt[mA/µs]

2.45

2.4

-50 0 50 100 150

Tj [°C]

Figure 14. Error Amplifier Slew Rate

VCOMP [V]

5

= 100 pF

L

open loop

Ω

4

3

VCOMP

V

FB

RL =10k

C

2

1

0

0 2 4 6 8 10121416

t[µs]

7/23