SGS Thomson Microelectronics TN22-1500H, TN22-1500B Datasheet

®

Application Specific Discretes

A.S.D.™

TN22

STARTLIGHT

FEATURES

High clamping voltage structure (1200 - 1500V)

n

Low gate triggering current for direct drive from

n

2, TAB

1

3

line (< 1.5mA)
High holding current (> 175mA), ensuring high

n

TAB

striking energy.

DESCRIPTION

The TN22 has been specifically developed for use

1

2

3

1

2

3

in electronic starter circuits. Use in conjunction
with a sensitive SCR and a resistor, it provides
high energy striking characteristics with low trig-

DPAK

(TN22-B)

IPAK

(TN22-H)

geringpower.Thankstoitselectronicconcept, this
TN22based starter offers high reliabilitylevels and
extended life time of the fluorescent tubelamps.

ABSOLUTE RATINGS (limiting values)

Symbol Parameter Value Unit

V

DRM

I

T(RMS)

Repetitive peak off-state voltage
RMS on-state current

= 110°C 400 V

T

j

Tc= 95°C 2 A

Full sine ware (180° conduction angle)

TAB

I

T(AV)

Mean on-state current
Full sine ware (180° conduction angle)

I

TSM

Non repetitive surge peak on-state current
(T

2

t

I

dI/dt

2

I

t Value for fusing

Critical rate of rise of on-state current
IG=5mA dIG/dt = 70 mA/µs.

T

stg

T

j

Tl

Storage and operating junction temperature range

Maximum lead temperature for soldering during 10s at

4.5mm from case

October 2000 - Ed:1

initial = 25°C)

j

Tc= 95°C 1.8 A

tp = 8.3ms 22 A

tp = 10ms 20

tp = 10ms 2 A

50 A/µs

-40to+150

°C

-40to+110
260 °C

2

s

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TN22

THERMAL RESISTANCES

Symbol Parameters Value Unit

Rth(j-a)
Rth(j-c)

Junction to ambient
Junction to case

100 °C/W

3 °C/W

GATE CHARACTERISTICS (maximum values)
P

= 300 mW PGM=2W(tp=20µs) I

G (AV)

=1A(tp=20µs) V

FGM

RGM

=6V

ELECTRICAL CHARACTERISTICS

Symbol Test conditions Type Value Unit

I

GT

V

GT

I

H

V

TM

I

DRM

dV/dt

VD=12V (DC) RL=33Ω

VD=12V (DC) RL=33Ω

=1KΩ

R

GK

VGK=0V
ITM= 2A tp= 380µs

V

Rated

DRM

Linear slope up to

=67%V

V

D

DRMVGK

=0V

Tj= 25°C MAX 1.5 mA
Tj= 25°C MAX 3 V

Tj= 25°C MIN 175 mA
Tj= 25°C MAX 3.1 V
Tj= 25°C MAX 0.1 mA

Tj= 110°C MIN 500 V/µs

Symbol Test conditions Type

V

BR

ID= 5mA VGK= 0V Tj = 25°C

MIN 1200 V

MAX 1500 V

Value

TN22-1500

Unit

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TN22

This thyristor has been designed for use as a fluo­rescent tube starter switch.

An electronic starter circuit provides :

BASIC APPLICATION DIAGRAM

INDUCTANCE

BALLAST

AC

VOLT AGE

FLUORESCENT

TUBE

A pre-heating period during which a heating

■

current is applied to the cathode heaters.
One or several high voltage striking pulses

■

across the lamp.

STARTER CIRCUIT

R

TN22

S

CONTROLLER

(TIMER)

PRINCIPLE OF OPERATION

1/ Pre-heating
At rest the switch S is opened and when the mains

voltage is applied across the circuit a full wave rec­tified current flows through the resistor R and the
TN22 gate : at every half-cycle when this current
reaches the gate triggering current (I

) the thyris-

GT

tor turns on.
When the device is turned on the heating current,

limited by the ballast choke, flows through the tube
heaters.
The pre-heating time is typically 2 or 3 seconds.

2/ Pulsing
At the end of the pre-heating phase the switch S is

turned on. At this moment :
Ifthe current through the devices is higher than the
holding current (I
the current falls below I

) the thyristor remains on until

H

. Then the thyristor turns

H

off.
If the current is equal or lower than the holding cur­rent the thyristor turns off instantaneously.

When the thyristor turns off the current flowing
through the ballast choke generates a high voltage

pulse. This overvoltage is clamped by the thyristor
avalanche characteristic (V

BR

).

Ifthe lamp isnot struck afterthe first pulse,the sys­tem starts a new ignition sequence again.

3/ Steady state
When the lamp is on the running voltage is about

150V and the starter switch is in the off-state.

IMPLEMENTATION

The resistor R must be chosen to ensure a proper
triggering in the worst case (minimum operating
temperature) according to the specified gate trig­gering current and the peak line voltage.

Switch S : This function can be realized with a gate
sensitive SCR type : P0130AA 1EA3
This component is a low voltage device (< 50V)
and the maximum current sunk through this switch
can reach the level of the thyristor holding current.

The pre-heating period can be determined by the
time constant of a capacitor-resistor circuit
charged by the voltage drop of diodes used in se­ries in the thyristor cathode.

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