MPPC High Voltage

Puprose

Provides control and monitoring of the MPPC high voltage (~48V to 73V).

Description

The MPPC High Voltage is generated by a Charge Pump Voltage located on the FEB64 card. Voltage setting is done through two independent channel:

• A common High Voltage generator (charge pump) for all the MPPC channels of the card (64).
• The Bias voltage control, through individual DAC for all the 64 channels with a voltage span of 5V maximum.

The slow control provides the necessary voltage control and monitoring of this local global Charge Pump Voltage and solely control (set) the 64 Bias Voltage 0..5V. The Qpump voltage (VBias) is then split in 8 branches feeding 8 consecutive MPPC (VBMon) each. A Bias 8 Branches Switch allows disconnection of individual branch through a 8 bit switch (swBias). In addition the slow control has a global command to toggle the MPPC common high voltage (MSCB(2)/0x02).

The voltage and current of the charge pump (V/IBias) and of the 8 Bias branches (V/IBMon) are periodically read for monitoring purpose. Possible procedure can be implement for voltage or current misbehaviour.

MSCB Registers

MSCB(1): Error     16bit U               0 (0x0000)         (RO)
Qpump Voltage fault                         0x0001
Qpump Current fault                         0x0002

MSCB(2): Control    8bit U               0 (0x00/00000000)  (WO)
Turn ON Charge Pump Voltage                          0x02

MSCB(3): Status     8bit U               3 (0x03/00000011)  (RO)
Charge Pump Voltage ON                               0x02

MSCB(5): swBias      8bit U             255 (0xFF/11111111) (WO)

MSCB(6): rQpump     16bit U             906 (0x038A) byte   (WO)

MSCB(7): VBias      32bit F         69.9437 volt            (RO)
MSCB(8): IBias      32bit F          0.9975 milliampere     (RO)

MSCB(31): VBMon0    32bit F         70.1584 volt            (RO)
MSCB(32): VBMon1    32bit F         11.1906 volt            (RO)
MSCB(33): VBMon2    32bit F          70.195 volt            (RO)
MSCB(34): VBMon3    32bit F         70.1468 volt            (RO)
MSCB(35): VBMon4    32bit F         70.1757 volt            (RO)
MSCB(36): VBMon5    32bit F         69.4225 volt            (RO)
MSCB(37): VBMon6    32bit F         70.2277 volt            (RO)
MSCB(38): VBMon7    32bit F         70.1892 volt            (RO)

MSCB(39): IBMon0    32bit F               0 microampere     (RO)
MSCB(40): IBMon1    32bit F        0.786781 microampere     (RO)
MSCB(41): IBMon2    32bit F               0 microampere     (RO)
MSCB(42): IBMon3    32bit F        0.655651 microampere     (RO)
MSCB(43): IBMon4    32bit F         47.0698 microampere     (RO)
MSCB(44): IBMon5    32bit F         44.3995 microampere     (RO)
MSCB(45): IBMon6    32bit F         15.5807 microampere     (RO)
MSCB(46): IBMon7    32bit F         36.8834 microampere     (RO)

Condition

Status register will reports a successful charge pump conditon when the VBias is higher than a low limit set currently at 30V. Error condition procedure on the actual Vbias, IBias and V/IBMon[0..7] is not yet implemented.

Location

On the FEB64 board

DataSheets

HV branch switch PCA9539PW-T

U/I Bias ADC LTC2495

Bias DAC LTC1665CGN#PBF