Gas Plasma Voltage Dependent Switches
Switching Gas Discharge Tubes
318 www.littelfuse.com
VS Series
The VS Series is a 2-terminal bi-directional, voltage triggered
switch designed for gas fuel ignition systems and similar circuits.
Switching voltages for the devices are fixed depending on the
part number selected. The gas plasma trigger technology offers
very fast switching speeds, resulting in significantly better di/dt
values when compared to silicon based SIDAC devices. Due to
the high switching voltage of the devices, step-up transformer
sizes and specifications can be reduced saving cost, size and
weight.
Features
• RoHS compliant
• Ceramic chamber for ultimate reliability.
• Very high switching speed once switching voltage has
been reached, resulting in high di/dt to be generated
enabling the best performance to be extracted from
ignition transformers.
Applications
• For switching stored electrical energy (such as capacitive
discharge) at predetermined voltages.
• Designed for in gas fuel ignition systems and similar circuits.
+0.20
-0.20
+0.20
-0.20
60.0
6.0
8.0
+4
Mechanical Specifications:
Weight: 1.42g (0.049oz.)
Materials: Electrode Base: Copper alloy
Electrode Plating material: Bright Sn
Body: Ceramic
Device Marking: Littelfuse ‘LF’ marking, voltage and
product code
RoHS
Switching Gas Discharge Tubes
Gas Plasma Voltage Dependent Switches
319
www.littelfuse.com
7
SWITCH GAS
DISCHARGE TUBES
VS Series
LT device
V
O.C. DC voltage =1000
0.22µF
51KΩ
Fig 1. Recommended breakover voltage test circuit
(Discharge current = 10-20mA; Sensitivity of
peak voltage detect = 10-30mA)
P.V.D.
VS device
V
15KΩ
2.2µF
32µH
230Vac
Fig 2. Recommended Life Test Circuit
Part
Number
Device Ratings and Specifications
VBO(1)
(V) VT
IDRM (2)
(A)
IBO (3)
(mA) Capacitance
VBO to VT
(nS)
VS230 200 –255 15 1.0 50 2.0 25
VS450 350 – 550 15 1.0 50 2.0 25
VS600 400 – 750 15 1.0 50 2.0 25
Electrical Life:
Maximum Increase in VBO(1) …………………………………………………... 25 V
Switching Operations (6) ………………………………………………………… 1,000,000
Maximum Ratings:
Surge On-State Current (5) ……………………………………………………… 1000A
Storage Temperature TSTG ……………………………………………………… -40 - +150˚C
Operating Temperature ……………………………………………………… -40 - +150˚C
Notes:
(1) Measured on recommended test circuit (fig 1.)
(2) Measured @ 100 Volts DC
(3) Current required for transition to on-state
(4) Measured @ 1 MHz, zero Volt bias
(5) Using 8/20µs double exponential pulse
(6) Measured on recommended test circuit (fig 2.)
Definitions:
VBO – Breakover Voltage
VT – Voltage when device is fully conduction – arc voltage
IDRM – Off-state Current
IBO – Nominal Breakover Current
VBO to VT– Max switching time from VBO to VT
RoHS
