1/14

EFS

May 2000 - Ed: 5A

STARLIGHT-KIT

2-CHIPS SET FOR FLUORESCENT LAMP STARTER

PENTAWATT HV

EFS21-TL5

Very low component count: 2 chips + 7 passive
components

Meet

EN55015

standards

WITHOUT

EMI

capacitor

Extended life time of the fluorescent lamp due to
smooth and single shot ignition

High inherent reliability and extended life time
of the starter

BENEFITS

The EFS Kit is a 2 chips set used with 7 additional
passive components, for Glow switch Starter.

The

ASD

(Application

Specific

Discretes)

includes a bi-directional Power Switch and a
Power Supply for the driver.

The driver provides a program to ensure a fully
optimised linear fluorescent lamp ignition.

DESCRIPTION

Application Specific Discretes

A.S.D.

S014

EFS2A-CD
EFS2B-CD

VERY WIDE TEMPERATURE RANGE:
tube ignition from - 30 to + 85

SINGLE SHOT IGNITION FROM -30 to 0

C :

350mA, 1350V striking pulse

VERY WIDE POWER RANGE:
Fluorescent tube lamp ignition from 18 to 70W

EFS2B driver compatible with 50/60Hz
operation

SELECTABLE PREHEAT TIME:
EFS2A driver: 1.5s or 2.56s (50Hz)
EFS2B driver: 0.74s or 1.24s (50Hz)
EFS2B driver: 0.62s or 1.03s (60Hz)

8 STRIKING PULSES CAPABILITY:
for very cold environment or ageing lamp

STARTER SHUTDOWN WITH FAILED LAMP

FEATURES

TM : ASD is trademark of STMicroelectronics.

EFS

2/14

MAINS FREQUENCY

50Hz

60Hz

DRIVER VERSION

EFS2A

EFS2B

Pin 2 connection

GND

VCC

GND

VCC

GND

VCC

PREHEAT DURATION

1.5s

2.56s

0.74s

1.24s

0.62s

1.03s

ASD

EFS21

LAMP POWER RANGE

18 to 70W (note 2)

AMBIENT TEMPERATURE RANGE

-30 to 85

C (note1, note 2)

Note 1: below -20

C, it is recommended to limit the lamp power range to 58W.

Note 2: the ignition temperature range is given with starting aid, as required in the IEC 81 and IEC 926 (§6.3.1) standards.

EFS STARLIGHT-KIT PARTS SELECTION:
The EFS STARLIGHT-KIT answers effectively to linear fluorescent lamp ignition needs:

DRIVER: EFS2A-CD

and

: EFS2B-CD

ASD

: EFS21-TL5

State tube detection

Shunt

Preheat select

to be grounded

VCC

GND

DO NOT CONNECT

to be grounded

SO14

Pentawatt HV

Vcc

Tube

GND

PIN CONNECTION (top view)

FLUORESCENT

LAMP

18W TO 70W

BALLAST

MAINS

7/8/10/11

2/3/5/6

150K

0.39

F - 16V

DRIVER

ASD

DO NOT
CONNECT

BASIC APPLICATION DIAGRAM

EFS

3/14

WORKING AREA

LAMP POWER (W)

Tamb (

(see note 2)

70 W

58 W

36 W

18 W

-30

-10

-20

RECOMMENDED LAMP POWER RANGE APPLICATION

Note 2: the ignition temperature range is given with starting aid, as required in the IEC 81 and IEC 926 (§6.3.1) standards.

Symbol

Parameter

Value

Unit

Top

Operating Junction temperature range

-30 to +125

Tstg

Storage temperature range

-55 to +150

ABSOLUTE RATINGS (limiting values)

Symbol

Parameter

Value

Unit

Vcc

Maximum supply voltage

Ptot

Power dissipation

500

ESD

Electrostatic discharge between any pins
Standard: MIL STD 883C Human Body Model

SENSE

Input operating range

DRIVER: EFS2 A & EFS2B

Symbol

Parameter

Value

Unit

T(RMS)

RMS on-state current

Tcase = 90

Tcase

T(RMS)

= 1A

OFF

= 0.16s

= 0.75s

+ 120

TSM

Surge peak on-state current
T

initial = 25

C, tp = 10ms

Minimum repetitive rate periode : 1min.

DRM

RRM

Repetitive peak off-state voltage

600

ASD

: EFS21

EFS

4/14

DRIVER

EFS

A/B

EFS

TL5

Electronic
Fluorescent
Switch

Kit

Version
Digit
A: 50Hz
B: 50/60Hz

Version
Digit

SO14
Package

TL5:
Pentawatt HV Package

with lead forming

ASD

ORDERING INFORMATION

ELECTRICAL CHARACTERISTICS (T

= 25

C, unless otherwise specified)

Symbol

Parameter

Min.

Typ.

Max.

Unit

Vcc

Supply voltage in preheat mode

UVLO

Under voltage lock-out threshold

CCH

Supply limitation high in standby mode

6.8

7.7

8.7

CCL

Supply limitation low in standby mode

6.77

7.57

8.41

Supply current in standby mode

440

450

475

Ignition current level Rsense = 0.39

280

350

420

LAMP OFF STATE DETECTION

Checking delay after zero crossing lamp voltage

EFS2A version

2.9

5.9

EFS2B version

2.5

7.5

REF

Internal reference voltage

1.12

1.26

DRIVER

Symbol

Parameter

Min.

Typ.

Max.

Unit

VT +

Positive on-state voltage

= 1.5A

tp = 500

2.1

3.15

VT -

Negative on-state voltage

= 1.5A

tp = 500

0.89

1.2

Breakdown positive voltage I

DRM

= 5mA

= 10ms

1200

1350

1500

DCM

RCM

Non repetitive peak off-state voltage
Pin 1 = Pin 2 = Pin 4 = Pin 5

Repetitive rate : 3Hz

800

DRM

RRM

Leakage current, at V

DRM

RRM

rated

Pin 1 = Pin 2 = Pin 4 = Pin 5

Holding current

dI/dt = 9 A/ms

Pin1 = Pin 2 = Pin4 = Pin5

350

ASD

EFS

5/14

7/8/10/11

3/5/6

DRIVER

ASD

THERMAL

FUSE

Vcc

GND

OPEN

one of the tracks

DEMONSTRATION BOARD DIAGRAM

Application Conditions

AC mains

Single

230V - 50Hz

Single

120V - 60Hz

Twin series 230V / 50Hz or

single 115V / 50Hz

Lamp Power Range

18 to 70W

18 to 36W

Ambient Temperature Range

-30 to + 85

C (note 3)

Recommended Components

ASD version

EFS21

Driver version

EFS2A or EFS2B

EFS2B

EFS2A or EFS2B

R1, R2

30k

- 0.125W - 5%

15k

- 0.125W - 5%

130k

- 0.125W - 5%

2.2k

- 0.25W - 5%

3.3k

- 0.25W - 5%

0.39

- 0.25W - 5% (note 4)

0.39k

- 0.25W - 5%

F - 16V - 20%

BYD17K (800V)

Note 3: below -20

C, it is recommended to limit the lamp power range to 58W.

Note 4: R5(Rsense) should have a 8 A, 10 ms surge capability.

RECOMMENDED COMPONENTS ACCORDING TO APPLICATION CONDITIONS

Pin 2 is the preheat time select pin. To select a short preheat time, drill to cut the Vcc to pin 2 track at the
metallic hole. To select a long preheat time, drill to cut the GND to pin 2 track. The layout must be
configured for either choice to avoid supply short circuit.

When the starter has to be protected against over-temperature, over-current or short circuit, it is
recommended to implement a thermal fuse in series with the starter.
To meet (IEC 926) standards, a capacitor (f.i. 5nF) can be connected between pin 3 and pin 4 of the ASD.

BOARD ASSEMBLY

DRILL and CUT the track
for SHORT preheat -->
for LONG preheat -->

PCB with Pentawatt HV and SO14

EFS

6/14

FLUORESCENT

TUBE

220V / 50HZ

BALLAST

V strike

The mains voltage is applied

Preheating of the tube

Striking of the tube

PREHEAT

EFS STARLIGHT-KIT APPLICATION NOTE

he Starter is a bi-directional switch which performs two functions:

the preheat of the tube,

the ignition of the tube.

1/ THE AC POWER SWITCH: FUNCTIONAL DESCRIPTION

During the preheat period, the ASD

is fully

conducting. The tube lamp is short circuited by the
starter, and the current flows through its filaments.
In these conditions, the lamp can not light up, but
the temperature of the lamp electrodes increases.

At the end of the preheat period, lamp filaments
are warm enough to emit electrons in the gas and
to permit the lamp ignition in good conditions. The
ASD

switches off the preheating current . At this

moment, the ballast is equivalent to a current
generator (I=I

SO,

= Switched Off current). As

the ASD

switches off, the starter voltage

increases. The amplitude of this high voltage spike
is then clamped by the ASD

1350 V). As

the starter and the lamp are in parallel, the striking
pulse is directly applied to the lamp. The
electromagnetic energy of the ballast is then
discharged through the lamp and the ASD

Striking pulse

The AC SWITCH merges an auxiliary power
supply for the driver, a power clamping device
(1350V) and a bi-directional switch with his
execution pilot block.

2/ WHAT'S NEW IN THIS SWITCH?

GND

Vcc

TUBE

Power supply

ON / OFF

DRIVER

SWITCH

HIGH

VOL

TAGE

CLAMPING

NEW EFS ASD

EFS

7/14

Present solutions work with a unidirectional
switch, like MOS transistors or GTO (Gate Turn
Off thyristor). As a starter is a bi-directional switch,
it is necessary to use a rectifier bridge (4 diodes of
1500V ). More, 2 or 3 diodes in series with the
GTO are required to get the necessary switch off
effect, and the whole is controlled with an analog
timer built around a small SCR.

The interest of a bi-directional switch arises itself:
a drastic reduction of the number of components,
and of course, a reduction of power losses (only 1
forward voltage instead of 5).

A lamp requires a minimum energy level to be ignited, but this energy depends especially on the lamp
temperature. The lower the temperature is, the more energetic the lamp strike is.

This energy stored in the ballast is directly proportional to the Switched Off current

L I

(

)

In other words, the required energy and of course the I

level, are maximum for the minimum

temperature. Results based on experiments show that it is necessary to switch off a current of 350 mA to
strike a 58W tube at -30

C (with a voltage amplitude clamped at 1200V and starting aid).

Therefore, the best way to strike a tube independently of the temperature is to keep the maximum I

level

for all the temperature range. Unfortunately, the solution is not so simple to implement because the energy
level at ambient or warm temperature would be much important: the lamp would be ignited, but the lamp
lifetime would be shortened. This is why one of the innovations of the ASD

is to modulate the striking

energy versus temperature (see feature hereafter).

3/ LAMP IGNITION FEATURE:

For freezing temperatures, the I

level is maintained at 350 mA, and for positive temperatures, the I

level decreases slowly.

GTO

SCR

1500V

Conventional discrete circuit (minimal version)

A.S.D.

FEATURE

I.S.O.

350mA

200mA

Switched off current
versus ambient temperature

EFS

8/14

In order to reduce the number of components, an
auxiliary power supply is integrated in the ASD

This active power supply works directly on the
mains and requires only a low voltage capacitor
16V - 22

F. The operating mode of this supply

varies with the starter operating phase:

4/ AUXILIARY POWER SUPPLY:

DRIVER

ASD

VCC

GND

TUBE

C SUPPLY

7.57

7.68

POWER SUPPLY SCHEMATIC

Supply operation during preheat phase:

During preheat phase, the driver manages alone the supply function (neither the driver nor D1 and R6 are
involved). A part of the current flowing through the ASD

is used, at the beginning and at the end of each

positive mains half cycle, to charge the output capacitor.

Supply operation during standby phase:

When the lamp is lit, the monitors its supply voltage (Vcc). At the beginning of each positive mains half
cycle, when Vcc is lower than 7.57V, the driver closes the ASD

supply switch. The capacitor is charged

to provide the standby current of the driver. During this phase the tube lamp is short circuited by the
ASD

. When the supply voltage reaches 7.68V, the driver opens the ASD

supply switch. Since this

current is also flowing in the ballast, the supply turn off provides across the lamp an additional voltage
spike. After running few minutes the lamp becomes warm and this spike voltage naturally decreases.

SUPPLY DURING PREHEAT PHASE

Starter current

Starter voltage

at the ignition

5min after

ignition

SUPPLY DURING STANDBY PHASE
(Without E.M.I. Capacitor nor R6 nor D1)

To reduce dramatically this repetitive voltage spikes across the lamp, the R6 resistor with the diode D1
provide a part of the supply current. Thus, the ripple voltage of the supply voltage is reduced, as well as the
level of the switched off current. On the other hand, this increases the safety margin of the RF noise
(versus the IEC 55015 limits)

EFS

9/14

5/ THE DRIVER: FUNCTIONAL DESCRIPTION

GND

G 1

G 2

Preheat
Select

Vcc

Shunt

State

tube

Minimum

Power supply

State tube detection

(Striked / Off)

0 current synchro

ISO synchro

350mA

Pre-heat

period

counter

1,5s
or
2.5s

Current generator

30mA

8 attempts

Strikes counter

UVLO

Clock 1/8

EFS2A DRIVER Internal block diagram (50Hz operation)

ALGORITHM

1. At switch on:

At switch on, an integrated Under Voltage Lock Out function (UVLO) resets the driver as long as the supply
voltage stays below a safety level.

2. Preheat:

The ignition sequence begins with the preheat
phase. Two different duration's can be selected with
PIN 2 (see table EFS STARLIGHT-KIT PARTS
SELECTION page 2).
During this phase, the driver maintains the ASD

a full ON-state making the starter equivalent to a
bi-directional conducting switch.

3. Ignition of the fluorescent tube:

At the end of the preheat period, the starter strikes
the fluorescent lamp.
For that, the driver reads continuously the current
through the starter. When the current reaches the
Switch Off level (I

= 350mA), the driver turns off

the ASD

. This induces a high voltage pulse across

the lamp. This pulse amplitude is limited by the
ASD

(

1350V).

4. If the lamp fails to strike:

The driver detects the state of the tube (lit or off). If it
stays off during 8 mains cycles (loop 1), a new
preheat period, shorter than the first one, starts
again (loop 3), followed by a new ignition attempt.
The driver will try to fire the tube 8 times. If none of
the 8 attempts succeeds in striking the lamp, the driver turns in standby mode, and the whole starter is fully
stopped until the next mains removal and power supply reset.

5. If the lamp is ignited:

If the lamp is ignited, the driver stays in standby mode while monitoring the state of the lamp (loop 2).
During normal operation of the tube, this short pulse is masked by the lamp conduction. If the mains
interruption is really long enough to turn off completely the lamp, a new ignition sequence starts again (loop
3) with 8 other new possible attempts.

AC MAINS ON

UVLO

RESET

Preheat *

1.5s or 2.5s

Strike

Attempt = Attempt + 1

Preheat *

0.75s or 1.25s

Attempt <8

YES

Loop 3

Loop 2

Tube

Ignited?

Fail = Fail + 1

Fail = 8

Fail = 0

Autosupply

Fail = 0

Attempt = 0

* see the preheat duration table § 6

Loop 1

EFS

10/14

The driver determines the preheat duration by counting mains cycles. This numeric solution brings
naturally a good precision depending only on the mains frequency tolerance.

With the 2 driver versions, the EFS startlight-kit provides a choice of 4 preheat duration's. The following
table gives the preheat duration before the first ignition attempt. The seven next preheat duration's, in case
of unsuccessful ignition attempt, last the half of the first one

6/ PREHEAT PHASE DURATION 50-60Hz:

PREHEAT DURATION

MAINS FREQUENCY

50Hz

60Hz

DRIVER VERSION

EFS2A

EFS2B

Pin 2 connection

GND

VCC

GND

VCC

GND

VCC

1.5s

2.56s

0.74s

1.24s

0.62s

1.03s

During the ignition sequence or once the lamp is lit, the starter checks the state of the lamp (lit or off).
To determine this state, the driver reads the lamp voltage through the resistor bridge (R1+R2+R3, R4).

- If the lamp is off, its voltage equal the mains voltage.

- If the lamp is lit, its voltage is only 80 V (for a 58W lamp).

Thus the lamp state is determined by comparison of the lamp voltage with a programmed detection level.

7/ TUBE STATE DETECTION:

min

MAX

min

MAX

LIT Lamp

Voltage

OFF Lamp

Voltage

CORRECT SETTING = NO WAVEFORM
ACROSS THE GREY AREA

Tolerance effects:

Tolerances on resistors (R1, R2, R3 and R4) as
well as on the integrated comparator bring a
tolerance on the set detection level. Thus the
detection level is included in a range delimited by
the maximum and the minimum detection levels
(DL

MAX

min

The driver checks the state of the lamp when
mains voltage is maximum, that is to say 5 ms after
the zero crossing mains voltage (50Hz). Here
again internal tolerances bring a tolerance on the
real checking moment (TC

min

MAX

How to set the detection level?

Only the R4 resistor value can be set to adjust the detection level. Values of resitors R1 to R3 must match
values of the table RECOMMENDED COMPONENTS ACCORDING TO APPLICATION CONDITIONS of
the page 5. Practically the R4 resistor value has to be set so that neither the OFF lamp voltage nor the LIT
lamp voltage cross the grey area.

The DL

MAX

and DL

min

limits can be calculated as follows:

x R

MAX

1265

(

)

and

min

1122

(

)

min

x R

MAX

EFS

11/14

As required in the IEC 926 standard (§11.5),
"starters which are interchangeable with glow
starters in accordance with IEC 155 shall contain
means for radio interference suppression, the
effect of which is equivalent to that of the radio
interference suppression capacitor prescribed in
7.12 of IEC 155".

The EFS starlight-kit is compatible with this 5nF
E.M.I. Capacitor which must be connected directly
across the ASD

(between pin 3 "TUBE" and pin

4 "GND").

On the other hand, this E.M.I. capacitor increases
the striking pulse width of about 55% on positive
temperatures.

8/ E.M.I. CAPACITOR:

7/8/10/11

2/3/5/6

Rsense

DRIVER

ASD

E.M.I.

8.1. Operation in single lamp configuration

The EFS STARLIGHT-KIT is ideal in the following configurations:

- Single Starter / 230V / 50Hz - Single Starter / 230V / 60Hz - Single Starter / 120V / 60Hz

MAINS

T
U
B
E

Note 4: the different driver versions should be chosen according to the table "EFS STARLIGHT KIT PARTS SELECTION" page 2.

Note 5: Components to choose are listed in the table "RECOMMENDED COMPONENTS ACCORDING TO APPLICATION CONDITIONS"
page 5.

8.2. Operation with capacitor for power factor correction:

The EFS STARLIGHT-KIT is also suitable for magnetic ballast including front end parallel capacitor.

The EFS STARLIGHT-KIT is NOT suitable for magnetic ballast including front end serial capacitor.

T
U
B
E

LEADING MAGNETIC BALLAST WITH
SERIAL CAPACITOR

MAINS

T
U
B
E

MAGNETIC BALLAST WITH SHUNT
PARALLEL CAPACITOR

EFS

12/14

8.3. Operation on the 230V/50Hz AC mains in twin tubes configuration

The EFS STARLIGHT-KIT is also suitable for the configurations Twin tubes Starter

Note 5: Components to choose are listed in the table "RECOMMENDED COMPONENTS ACCORDING TO APPLICATION CONDITIONS"
page 5.

The only electrical diagram difference consists of the R4 resistor which needs to be changed from 1 to
2.2k

. Without this modification, the starter will generate only one ignition attempt instead of 8 in case of

defective lamp; the loop 3 is removed from the algorithm described in page 9.

In the Twin Series 230V/50Hz configuration, the polarity of the two starters must be respected:

In case of no operation of starters, rotate one of the starters of 180

on its socket.

230V / 50HZ

BALLAST

STARTER

SOCKET

FLUORESCENT
TUBE

OFF

ALIGHT

Rotate of 180

only one starter

MAINS

230V

TWIN TUBE

EFS

13/14

PACKAGE MECHANICAL DATA
SO14 (Driver)

Dim.

Millimeters

Inches

Min.

Typ. Max. Min.

Typ. Max.

1.75

0.069

0.1

0.2

0.004

0.008

1.6

0.063

0.35

0.46 0.014

0.018

0.19

0.25 0.007

0.010

0.5

0.020

(typ.)

8.55

8.75 0.336

0.334

5.8

6.2

0.228

0.244

1.27

0.050

7.62

0.300

3.8

4.0

0.150

0.157

4.6

5.3

0.181

0.208

0.5

1.27 0.020

0.050

0.68

0.027

(max.)

EFS

14/14

PACKAGE MECHANICAL DATA
Pentawatt HV with lead forming - TL5 (ASD

)

REF.

DIMENSIONS

Millimeters

Inches

Min.

Typ.

Max.

Min.

Typ.

Max.

4.3

4.8

0.169

0.188

1.22

1.42

0.048

0.056

2.4

2.8

0.094

0.110

DIAM

3.65

3.85

0.144

0.152

0.35

0.45

0.014

0.018

0.65

0.75

0.026

0.030

4.88

5.28

0.192

0.208

7.42

7.82

0.292

0.308

10.4

0.409

10.05

10.4

0.396

0.409

3.3

0.130

14.24

14.64 0.560

0.576

2.34

2.74

0.092

0.108

2.6

0.102

0.118

15.1

15.8

0.594

0.622

6.6

0.236

0.260

0.5

0.020

Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the consequences of
use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written ap-
proval of STMicroelectronics.

The ST logo is a registered trademark of STMicroelectronics

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