ST L6585DE User Manual

Features

■ PFC section

– transition mode PFC with over-current

protection
– over-voltage protection
– feedback disconnection
– under-voltage lockout
– PFC choke saturation detection
– THD optimizer

■ Half-bridge section

– preheating and ignition phases

independently programmable
– 3 % oscillator precision
– 1.2 µs dead time

L6585DE

Combo IC for PFC and ballast control

SO-20

– programmable and precise end-of-life

protection compliant with all ballast

configurations
– smart hard switching detection
– fast ignition voltage control with choke

saturation detection
– half-bridge over-current control

Figure 1. Block diagram

April 2009 Rev 2 1/33

www.st.com

33

Contents L6585DE

Contents

1 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.1 Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

1.2 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Electrical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

2.1 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

4 Device description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

5 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.1 VCC section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.2 PFC section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.1 TM PFC operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

5.2.2 Leading edge blanking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2.3 THD optimizer feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

5.2.4 Over-voltage protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.2.5 Disabling the L6585DE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.2.6 Feedback disconnection protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

5.2.7 PFC over-current protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6 Ballast section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.1 Half-bridge drivers and integrated bootstrap diode . . . . . . . . . . . . . . . . . 18

6.2 Normal start-up description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

6.3 Startup sequence with old or damaged lamps . . . . . . . . . . . . . . . . . . . . . 21

6.4 Old lamp management during run mode . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.5 Rectifying effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.6 Over-current protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

6.7 Hard switching protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

2/33

L6585DE Contents

6.8 Choke saturation protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

7 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

8 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3/33

Pin settings L6585DE

1 Pin settings

1.1 Connection

Figure 2. Pin connection (top view)

1.2 Functions

Table 1. Pin functions

Pin n. Name Function

1OSC

2RF

3EOI

An external capacitor to ground fixes the half-bridge switching frequency with a
± 3 % precision.

Voltage reference capable of sourcing up to 240 µA. The current sunk from this
pin fixes the switching frequency of the half-bridge for each operating state.

R

A resistor (
combined with the capacitor connected to the pin OSC.

A resistor connected to EOI (R
frequency during preheating combined with R

Connected to ground by a capacitor that, combined with R
ignition time.

Preheating
Ignition and run mode

HBCS threshold triggering.

) connected to ground sets the half-bridge operating frequency

RUN

) sets the maximum half-bridge switching

PRE

: low impedance to set high switching frequency

: high impedance with controlled current sink in case of

RUN

and C

.

OSC

, determines the

PRE

4/33

L6585DE Pin settings

Table 1. Pin functions (continued)

Pin n. Name Function

Pin for setting the preheating time and protection intervention.
Connect an RC parallel network (Rd and Cd) to ground.

Preheating

voltage reaches 4.63 V the generator is disabled and the capacitor discharges
because of R

4Tch

ignition phase starts and the RdCd is pulled to ground.

Ignition and Run mode:

impedance. During a fault (either over-current or EOL) the internal generator
charges the Cd to 4.63 V and then another current generator discharges the
same capacitor. In this way, C
time).

Pin to program the EOL comparator.

5EOLP

It is possible to select both the EOL sensing method (fixed reference or
reference in tracking with CTR) and the window comparator amplitude by
connecting a resistor (R

Input for the window comparator.

6EOL

It can be used to detect lamp ageing for either “lamp to ground” or “block
capacitor to ground” configurations.

This function is blanked during the ignition phase.

Input pin for:

- PFC over-voltage detection: the PFC driver is stopped until the voltage returns

7CTR

in the proper operating range

- Feedback disconnection detection

- Reference for EOL comparator (in case tracking reference)

- The pin can be used also for shutdown

8MULT

Multiplier external input. This pin is connected to the rectified mains voltage via a
voltage divider and provides the sinusoidal reference to the PFC current loop.

Output of the error amplifier. A compensation network is placed between this pin

9COMP

and INV to achieve stability of the PFC voltage control loop and ensure high
power factor and low THD.

10 INV

Inverting input of the error amplifier. Output voltage of the PFC pre-regulator is
fed to the pin through a voltage divider.

Boost inductor demagnetization sensing input for PFC transition-mode

11 ZCD

operation. A negative-going edge triggers PFC MOSFET turn-on.
During startup or when the voltage is not high enough to arm the internal

comparator, the PFC driver is triggered by means of an internal starter.

Input to the PFC PWM comparator. The current flowing through the PFC
MOSFET is sensed through a resistor. The resulting voltage is applied to this pin
and compared with an internal sinusoidal-shaped reference, generated by the

12 PFCCS

multiplier, to determine the PFC MOSFET’ s turnoff.
A second comparison level detects abnormal currents (due to boost inductor

saturation, for example) and, on this occurrence, shuts down the PFC gate.
An internal LEB prevents undesired function triggering.

: the Cd is charged by an internal current generator. When the pin

. Once the voltage drops below 1.5 V, the preheating finishes, the

d

During proper behavior of the IC, this pin is low

sets the fault timing (shorter than preheating

d

) to ground.

EOLP

5/33

Pin settings L6585DE

Table 1. Pin functions (continued)

Pin n. Name Function

13 PFG

14 HBCS

15 GND Ground.

16 LSD

17 VCC

18 OUT

19 HSD

20 BOOT

PFC gate driver output. The totem pole output stage is able to drive power
MOSFETs with a peak current of 300 mA source and 600 mA sink (typ. values).

3-level half-bridge current monitor for current control.
The current flowing through the HB MOSFET is sensed through a resistor. The

resulting voltage is applied to this pin.
First level threshold (1.05 V, active during run mode): in case of threshold

crossing the IC reacts with frequency increase in order to limit the half-bridge
(and lamp) current.

Second level threshold (1.6 V, active during ignition and run mode):

- Ignition
with frequency increase in order to limit the lamp voltage and preventing
operation below resonance.

- Run mode
example, to capacitive mode / cross-conduction) longer than 200 ns the
L6585DE is latched in low consumption mode to avoid damage to the
MOSFETs.

Third level threshold (2.75 V, active during ignition and run mode):

- Ignition
choke saturation), the IC latches to avoid damage to the MOSFETs.

- Run mode
duration equal to around 40 ns) an internal counter is increased. After around
350 (typ.) subsequent hard switching events the IC is latched in low consumption
mode.

Low side driver output: the output stage can deliver 290 mA source and 480 mA
sink (typ. values).

Supply voltage of both the signal part of the IC and the gate driver.
Clamped with a Zener inside.

High-side driver floating reference. This pin must be connected close to the
source of the high side power MOSFET.

High-side driver output: the output stage can deliver 290 mA source and 480 mA
sink (typ. values).

Bootstrapped supply voltage. Bootstrap capacitor must be connected between
this pin and OUT pin.

Patented, integrated circuitry replaces the external bootstrap diode by means of
a high voltage DMOS, synchronously driven with the low side power MOSFET.

: in case of threshold crossing during the frequency shift, the IC reacts

: in case of threshold crossing because of current spikes (due, for

: in case of threshold crossing during frequency shift (e.g. caused by

: in case of threshold crossing by a hard switching event (spike

6/33

L6585DE Electrical data

2 Electrical data

2.1 Maximum ratings

Table 2. Absolute maximum ratings

Symbol Pin Parameter Value Unit

V

BOOT

V

OUT

/dt 18 Floating ground max. slew rate 50 V/ns

dV

OUT

V

CC

20 Floating supply voltage -1 to 618 V

18 Floating ground voltage -3 to V

17 IC supply voltage (ICC = 20 mA)

(1)

Self-limited V

BOOT –

18 V

1, 3, 4,

8, 10, 12Analog input and outputs -0.3 to 5 V

2, 5 -0.3 to 2.7 V

V

V

V

EOL

CTR

HBCS

6 Maximum EOL voltage -0.3 to V

CC

7 Maximum CTR voltage -0.3 to 7 V

14 Maximum half-bridge current sense voltage -5 to 5 V

9, 11 Self-limited

I

RF

I

EOLP

F

OSC(MAX)

P

TOT

1. The device has an internal clamping Zener between GND and the VCC pin. It must not be supplied by a
low impedance voltage source.

2 Current capability 240 μA

5 Current capability 100 μA

Maximum operating frequency 250 kHz

Power dissipation @TA = 70 °C 0.83 W

Note: ESD immunity for pins 18, 19 and 20 is guaranteed up to 900 V (human body model)

V

2.2 Thermal data

Table 3. Thermal data

Symbol Description Value Unit

R

T

thJA

T

STG

Max. thermal resistance junction to ambient 120 °C/W

Junction operating temperature range -40 to 150 °C

J

Storage temperature -55 to 150 °C

7/33

Electrical characteristics L6585DE

3 Electrical characteristics

VCC = 15 V, TA = 25 °C, CL = 1 nF, C

= 470 pF, R

OSC

= 47 kΩ, unless otherwise specified

RUN

Table 4. Electrical characteristics

Symbol Pin Parameter Test condition Min. Typ. Max. Unit

Supply voltage

Vcc V

V

CC(on)

V

CC(OFF)

V

Z

V

V

V

Supply current

I

ST-UP

I

CC

V

V

Iq V

PFC section – multiplier input

I

V

ΔV

ΔV

MULT

MULT

CS

MULT

K

M

MULT Input bias current V

MULT Linear operation range V

MULT Output max. slope

MULT Gain V

PFC section – error amplifier

Operating range After turn-on 11 16 V

CC

Turn-on threshold

CC

Turn-off threshold

CC

(1)

(1)

13.6 14.3 15 V

9.6 10.3 11 V

Icc = 20 mA, TA = 25 °C 16.7 17.1 17.5 V

Zener voltage

CC

Start-up current Before turn-on @ 13 V 250 370 µA

CC

Operating supply current Fpfc = 50 kHz 7 mA

CC

Residual current IC latched 350 µA

CC

Icc = 20 mA, full
temperature range

= 0 V -1 µA

MULT

= 3 V 0 to 3 V

COMP

V

= 0 to 1 V,

MULT

= Upper clamp

V

COMP

MULT

= 1 V, V

= 3 V 0.52 1/V

COMP

16 17.1 18 V

0.75 V/V

V

I

INV

INV

INV

INV Line regulation V

INV Input bias current -1 µA

Voltage feedback input
threshold

CC

Gv INV Voltage gain Open loop

GB INV Gain-bandwidth product

I

COMP

COMP

Source current V

Sink current V

Upper clamp voltage I

V

COMP

V

DIS

COMP

INV

Lower clamp voltage I

Open loop detection
threshold

(2)

COMP

COMP

SOURCE

SINK

CTR > 3.4 V 1.2 V

COMP Static OVP threshold 2.1 2.25 2.4 V

8/33

2.47 2.52 2.57 V

= 10.3 V to 16 V 50 mV

(2)

60 80 dB

1MHz

= 4V, V

= 4V, V

= 2.4 V -2.6 mA

INV

= 2.6 V 4 mA

INV

= 0.5 mA 4.2 V

= 0.5 mA 2.25 V

L6585DE Electrical characteristics

Table 4. Electrical characteristics (continued)

Symbol Pin Parameter Test condition Min. Typ. Max. Unit

CTR pin

DIS CTR

Hysteresis 120 mV

Dynamic PFC over-

Shutdown threshold Falling edge 0.75 V

PFOV CTR

voltage

Hysteresis 140 mV

CTR

Available range as
tracking reference

PFC section – current sense comparator

I

CS

t

LEB

V

CSstop

t

d(H-L)

V

CSclamp

PFCS Input bias current V

PFCS Leading edge blanking

PFCS PFC stop threshold V

PFCS Delay to output 120 ns

PFCS

Current sense reference
clamp

PFC section – zero current detector

V

ZCDH

V

ZCDL

V

ZCDA

V

ZCDT

I

ZCDb

I

ZCDsrc

I

ZCDsnk

ZCD Upper clamp voltage I

ZCD Lower clamp voltage I

ZCD

ZCD

Arming voltage
(positive-going edge)

Triggering voltage
(negative-going edge)

ZCD Input bias current V

ZCD Source current capability -4 mA

ZCD Sink current capability 4 mA

PFC section – gate driver

Rising edge 3.4 V

Lower threshold (falling) 1.7 V

Hysteresis 120 mV

Higher threshold (rising) 3.4 V

Hysteresis 140 mV

= 0 V -1 µA

CS

(2)

CTR

= Upper clamp 1 1.08 1.16 V

V

COMP

= 2.5 mA 5 V

ZCD

= -2.5 mA -0.3 0 0.3 V

ZCD

(2)

(2)

= 1 to 4.5 V 1 µA

ZCD

100 200 300 ns

1.65 1.75 1.85 V

1.4 V

0.7 V

I

= 10 mA 0.2 V

PFG Output high/low

SINK

I

SOURCE

= 10 mA 14.5 V

tf PFG Fall time 40 90 ns

tr PFG Rise time 90 140 ns

I

SINK

I

SOURCE

PFG Peak sink current 475 600 mA

PFG Peak source current 200 300 mA
PFG Pull-down resistor 10 kΩ

9/33

Electrical characteristics L6585DE

Table 4. Electrical characteristics (continued)

Symbol Pin Parameter Test condition Min. Typ. Max. Unit

Half bridge section – timing and oscillator

V

V

I

CH

CHP

CHN

T

T

T

T

Charge current V

CH

Charge threshold

CH

(positive going-edge)

Discharge threshold

CH

(negative going edge)

Leakage current

CH

= 2.2 V 31 µA

TCH

(1)

(1)

1.5 V < V

TCH

< 4.5 V,

4.53 4.63 4.73 V

1.50 V

falling

0.1 µA

During protection:

I

CHsnk

R

TCH

R

EOI

I

EOI

V

EOI

V

REF

I

RF

I

OSCratio

T

T

Discharge current

CH

Internal impedance Run mode 100 200 Ω

CH

EOI Open state current V
EOI EOI impedance During preheating 150 Ω

EOI current generator

EOI

during ignition and run
mode

EOI EOI threshold

RF Reference voltage

RF Max current capability 240 µA

OSC I

OSC/IRF

OSC Rising threshold

OSC Falling threshold

reduced timing

= 3 V

V

TCH

= 2 V 0.15 µA

EOI

Tspike = 200 ns

Tspike = 400 ns

Tspike = 600 ns

Tspike = 1 µs

(1)

(1)

V

= 3 V 4

OSC

(1)

(1)

(3)

(3)

(3)

(3)

1.83 1.9 1.98 V

1.92 2 2.08 V

26 µA

20

100

200

270

3.7 V

0.9 V

D OSC Output duty cycle 48 50 52 %

T

DEAD

F

F

RUN

PRE

OSC Dead time 0.96 1.2 1.44 µs

OSC

OSC

Half-bridge oscillation
frequency (run mode)

Half-bridge oscillation
frequency (preheating)

58.4 60.2 62 KHz

R

= 50 kΩ 113.2 116.7 120.2 KHz

PRE

µA

Half bridge section – end-of-life function

I

EOLP

V

EOLP

EOLP Current capability 100 µA

EOLP Reference voltage 1.92 2 2.08 V

EOL Operating range EOLP = 27 kΩ 0.95 4.15 V

220 kΩ < R
kΩ or 22 kΩ < R

V

S

EOL

Window comparator
reference

27 kΩ

R

EOLP

75 kΩ < R

10/33

< 270

EOLP

EOLP

> 620KΩ or

< 91 kΩ

EOLP

<

tracking with CTR

V

2.5