ISDN Remote Power Controller (IRPC)

The PSB 2120 is a Pulse Width Modulator (PWM) circuit designed for fixed-frequency switching regulators especially for telephony and ISDN-environments.
The PSB 2120 is fully compatible with the CCITT-power recommendations on the “S”-interface.
Coupled with a few external components it can provide a stable 5 V DC-supply for subscriber terminals (TE’s) or network terminators (NT’s). It can also be programmed for higher output voltages, e.g. to supply the S-lines with 40 V.
In telephony and ISDN-systems a high conversion yield is crucial to maintain functionality in all supply conditions via “S”- or “U”-interfaces. The PSB 2120 design and technology realizes high conversion efficiency and low power dissipation.
It should be recognized that the PSB 2120 can also be used in numerous DC/DC-conversion systems other than ISDN-power supplies.

Features
● Switched mode DC/DC-converter
● Switched mode DC/DC-converter
● CCITT (I.430) ISDN compatible
● Integrated 200 V power FET
   (only PSB 2120-P in P-DIP-22)
● Low power dissipation
● Supply voltage range 10 V to 60 V
● Input undervoltage detection
● Programmable overcurrent protection
● Soft start
● Control circuit to achieve minimum start-up current
● Power housekeeping input
● Oscillator synchronization input/output
● Polarity reversal detection
● High voltage CMOS-technology 60 V