Fundamental Technologies

Voyager LECP Pages

Specifications for LECP Pulse Height Analyzer

Power A/D Circuit
Standby		 A/D Circuit
During Conversion		 Peak Detector
Circuit
+12.0 V 1 mA 17 mA 4 mA
  8.0 1 4 7
  6.0 1 1 13
-6.0 nil 8 23
-12.0 2 4 not reqd.
Resolution: 10 bits - 1023 counts full scale
Accuracy: Digital voltmeter section with multiplexer (both LEPT and LEMPA models):
0.1% or 1 bit from calibration @ 25ºC against channel calibration
0.3% max observed absolute deviation between channels at 25ºC
0.6% max observed absolute deviation from 25 to -50ºC
0.5% max observed deviation for power supply variation of 10%
See Calibration Table and Test Records for additional data.
Range: LEPT Mode - 0 to 2.00 volts
LEMPA Mode - 0 to 8.00 volts
Peak Detector Characteristics: Offset error less than 20 mV (1%) over the environment.
Transmitted resolution - 8 bits - 0.5% - 8 mV
Maximum droop error for last channel converted
   (@60ºC) - 2% - 30 mV
   (@25ºC) < .6% - 12 mV
Error from 10% power supply variation - less than 0.5% - 8 mV max @ 25ºC
Clock Frequency
(external)		 50 kHz (range of about 45 to 80 kHz acceptable).
Calibration LEPT:  3 point calibration @ 0.2%, 6%, and 45%.  Counts 0002, 0060, 0457 (1023 FS).
LEMPA:  2 point calibration @ 0.2% and 98.3%.  Counts 0002, 1005 (1023 FS).
Note the last two bits are not transmitted in LEPT mode and the telemetered values read 000, 060, 456 for Full Scale of 255 counts.
Multiplexer protection: 10 kohm input resistor all channels
Interface protection: Series resistors all input and output lines.
Output levels have 100 nSec risetimes.
Output levels are 15 KW to ground when power is OFF.

Return to Voyager LECP Data Analysis Handbook Table of Contents.
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Last modified 6/20/03, Tizby Hunt-Ward
tizby@ftecs.com