Looks like its 50MA
http://www.mkivsupra.net/vbb/showthread.php?237136-People-with-Alarms-specifically-the-Clifford-650/page2
Mine is a 650MkII, but the current draw shouldn't be much (if any) different to the original 650.
When the alarm is activated and the sensors have come on, the total drain on the battery (including whatever the head unit, internal clock etc takes) is 53 - 63mA. The variation will be down to the flashing alarm LED and probably also the way some the four sensors work.
When the alarm is in 'valet' mode the drain is 43mA steady.
When the alarm is off and starting is immobilised (sensors are not activated), the drain is 37mA - 43mA (varies due to flashing LED).