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SEPTEMBER 1995 - REVISED SEPTEMBER 1997

TISP61060D, TISP61060P

DUAL FORWARD-CONDUCTING P-GATE THYRISTORS

PROGRAMMABLE OVERVOLTAGE PROTECTORS

PRODUCT

INFORMATION

APPLICATIONS INFORMATION

electrical characteristics

The electrical characteristics of a thyristor overvoltage protector are strongly dependent on junction

measurement. The values given in this data sheet were measured on commercial testers, which generally

minimise the temperature rise caused by testing.

gated protector evolution and characteristics

This section covers three topics. Firstly, it is explained why gated protectors are needed. Second, the

performance of the original IC (integrated circuit) based version is described. Third, the performance

improvements given by the TISP61060 are detailed.

purpose of gated protectors

Fixed voltage thyristor overvoltage protectors have been used since the early 1980s to protect monolithic

SLICs (Subscriber Line Interface Circuits) against overvoltages on the telephone line caused by lightning, a.c.

power contact and induction. As the SLIC was usually powered from a fixed voltage negative supply rail, the

limiting voltage of the protector could also be a fixed value. The TISP1072F3 is a typical example of a fixed

voltage SLIC protector.

SLICs have become more sophisticated. To minimise power consumption, some designs automatically adjust

supply voltage would be set low, but for long lines, a higher supply voltage would be generated to drive

sufficient line current. The optimum protection for this type of SLIC would be given by a protection voltage

which tracks the SLIC supply voltage. This can be achieved by connecting the protection thyristor gate to the

SLIC supply, Figure 2. This gated (programmable) protection arrangement minimises the voltage stress on

the SLIC, no matter what value of supply voltage.

CROSS-REFERENCE FOR TISP61060 AND LB1201AB

TISP61060 PARAMETER

DATA SHEET

SYMBOL

ALTERNATIVE

SYMBOL

ALTERNATIVE PARAMETER

RATINGS & CHARACTERISTICS

LB1201AB

Non-repetitive peak on-state pulse current

Pulse current

Non-repetitive peak on-state current

RMS pulse current, 60 Hz

On-state voltage

On-state voltage

Switching current

Trip current

Breakover voltage

Trip voltage

Maximum continuous on-state current

On-state current

Maximum continuous forward current

On-state current

to the A terminal)

Supply voltage

Off-state capacitance

Off-state capacitance

TERMINALS

LB1201AB

Cathode 1

K1

Tip

Tip

Cathode 2

K2

Ring

Ring

Anode

A

GND

Ground

Gate

G

Supply voltage