Product Description

The Hytec Type 90 Converter basically consists of 8 bi–directional level converters. Each level converter consists of sub–sections lettered A to H. The basic action of the circuit is controlled by three switches. S1 controls whether the unit accepts a NIM level or a TTL level. When set to the NIM level a red LED associated with that particular subsection is illuminated. When set to NIM, S2 controls whether the input is inverted or not. A green LED shows whether the input has been inverted or not; it is illuminated when the unit is non–inverted. NOTE: the non–inverting state is such that a zero input current on the main input will give a high voltage output on the TTL output. When set to TTL inputs the inverting/non–inverting state is controlled by S3 and is still indicated by the green LED.

Provision has been made in the circuit for the output current on the NIM output driver to be increased so that it will drive approximately 50mA when being used as a TTL to NIM converter. This is achieved by joining link 1. Unless multiple terminated inputs are being driven it is recommended that this link is not made. When being used as a TTL input, a common gate line has been incorporated. This simply allows a TTL 1 signal (low) to inhibit all the sections. However, each section’s response is controlled via a wire link to the link 2. Link 2 is normally made on all sections.

Specification

Logic 0
Current is less than – 1mA.
TTL Inputs/Outputs.
Input 1 TTL load.
Output 10 TTL Fan out.

NIM/TTL Converter

Max. frequency:	85MHz
Rise and Fall times:	3nSec
Min. pulse width:	6nSec

NIM Inputs
Logic 0: Terminated into 50 Ohms, inputs will accept as a ’0’ state – 4mA (200mV) to + 20mA (1V).

NIM Outputs
Logic 1: Drives – 16mA into 50 Ohms in one state (with link 1 made drives approximately – 32mA). (This does not include current being driven into its internal 50 Ohm load).

TTL/NIM Converter

Max. frequency:	50MHz
Rise and Fall times:	4nSec
Min. pulse:	10nSec

Power Requirements

+6V	0.5 Amp
-6V	0.5 Amp

Logic 1:
Input will accept –12mA to –36mA (600mV to 1.8V into 50 ohms).