Array Photometer

Circuit Design and Interface

Tohoku University

CDR Meeting, July 2001

Data acquisition mode

a. Sprite 1 Mode : S_MODE_SPRITE2sampling rate=20KHz, fc(LPF)=10 KHz

b. Sprite 2 Mode : S_MODE_SPRITE20sampling rate=2KHz, fc(LPF)=10KHz

c. Auroral Mode : S_MODE_AURORAsampling rate=200Hz, fc(LPF)=100Hz

Science data format is 12 bits serial.

Nominal DATA_CLK frequency is 5MHz.

2 KHz20KHz 20KHz

18ms 82 ms

S_MODE_SPRITE2 S_MODE_SPRITE20

18 ms

10 ms

Trigger sequence

Triggered by Cloud Flash

Triggered by Sprites

Functional Diagram for Array Photometer

8 ch

8 ch

8 ch

8 ch

10KHz, 1KHz, 100Hz

AEPAP

DATA_CLK+

DATA_CLK-

DATA_A+

DATA_B+

DATA-A-

DATA-B-

DATA_ENB++

DATA-ENB-

Drive:DS26C31 (NS)

[ RS-422 ]

Science Data Interface

DATA_ENB

DATA_CLOCK

DATA_A

DATA_B

B11

B10 B0

MSB

LSBB11

T1

B11 B10 B0

MSB

LSB

 

- Clock Rate is nominal 5MHz(duty 50%)- All signals RS-422- All signals driven low except driving transfer- All changes data on falling edge of DATA_CLOCK- AEP reads data on rising edge of DATA_CLOCK- Data length 12bits

AP

CMD_CLK+

CMD_CLK-

CMD_DATA+

CMD_DATA-

CMD_STB+

CMD_STB-

Receive:DS26C32 (NS)

[ RS-422 ]

AEP

Serial Command Interface

250ns

250ns

500ns 500ns

LSBMSB

500ns

C7 C6 C5 C4 C3 C2 C1 C0DO15

DO14

DO13

DO12

DO11O11

DO10DO9

DO8DO7

DO6DO5

DO4

DO3DO2DO1DO0

COMMAND COMMAND DATA

APPROX 13 us

CMD_CLK

CMD_DATA

CMD_STB

- CLOCK RATE is nominal 2MHz (duty 50%)- All signals are provided by RS-422- Command format is 8 bits- Data format is 16 bits

MODE Command Name OPERATION COMMAND CODE

Change Sampling Mode S_MODE_SPRITE20 SPRITE MODE 20KHz SAMPLING 60 hex

S_MODE_SPRITE2 SPRITE MODE 2KHz SAMPLING 61 hex

S_MODE_AURORA AURORA MODE 200Hz SAMPLING 62 hex

High Voltage Control HV_LOW_A CHANNEL A HV = TBD (LOW VOLTAGE) 68 hex

HV_LOW_B CHANNEL B HV = TBD (LOW VOLTAGE) 69 hex

HV_MID_A CHANNEL A HV = TBD (MID VOLTAGE) 6A hex

HV_MID_B CHANNEL B HV = TBD (MID VOLTAGE) 6B hex

HV_HIGH_A CHANNEL A HV = TBD (HIGH VOLTAGE) 6C hex

HV_HIGH_B CHANNEL B HV = TBD (HIGH VOLTAGE) 6D hex

HV_OFF_A CHANNEL A HV = 0V (OFF) 6E hex

HV_OFF_B CHANNEL B HV = 0V (OFF) 6F hex

Calibration CAL_ON CALIBRATION ON 78 hex

CAL_OFF CALIBRATION OFF 79 hex

ANALOG HOUSEKEEPER LINEMULTIPLEX

ANA_HKP_MUX DO15:+5V VOLTAGE MONITOR   7A hex

  DO14:+12V VOLTAGE MONITOR  

  DO13:-12V VOLTAGE MONITOR  

  DO12:PM1 TEMP MONITOR(PM1 room)  

  DO11:PM2 TEMP MONITOR(PM2 room)  

DO10:CONT TEMP MONITOR(Control room)  

DO9 :CHANNEL A HV MONITOR

DO8 :CHANNEL B HV MONITOR

ARRAY PHOTOMETER AEP/AP COMMAND INTERFACE

AP CMD_CLK+

CMD_CLK-

READBACK(CMD_DATA+)

READBACK(CMD_DATA-)

CMD_STB+

CMD_STB-

Drive:DS26C31 (NS)

[ RS-422 ]

AEP

Readback Interface

CMD_CLK(FROM DPU)

CMD_DATA(FROM DPU)

CMD_DATA(TO DPU)

CMD_DCOE (REF)

CDI_STB(FROM DPU)

C7 C6 C5 C4 C3 C2 C1C0

DI15

DI14

DI13

DI12DI11DI10DI9DI8DI7DI6DI5DI4DI3DI2DI1DI0(HI-Z)

(HI-Z)

(L = READBACK : H = COMMAND)

COMMAND READBACK

APPROX. 13.5 us

Readback Data

DI15 : SPRITE MODE 20KHz SAMPLINGDI14 : SPRITE MODE 2KHz SAMPLINGDI13 : AURORA MODE 200Hz SAMPLINGDI12 : CH_A_HV=LOWDI11 : CH_B_HV=LOWDI10 : CH_A_HV=MIDDI9 : CH_B_HV=MIDDI8 : CH_A_HV=HIGHDI7 : CH_B_HV=HIGHDI6 : CH_A_HV=OFFDI5 : CH_B_HV=OFFDI4 : CALIBRATION ONDI3 : CALIBRATION OFFDI2 : TOGGLE BIT(Alternate this bit with readback)

AP TRIGGER+

TRIGGER -

DAYLIGHT +

DAYLIGHT -

Drive:DS26C32 (NS)

[ RS-422 ]

AEP

Discrete Signal Interface

-Trigger: Start sampling

- Daylight: HV of AP shall be off according to the DAYLIGHT signal from AEP

DAYLIGHT

- AP does not have any shutter or caps.

- High Voltage power supply of AP shall be off when it receives daylight pulse issued by AEP

     

      

 

HK Data Range ANA-HKP Range

+5V 0 - +7 V 0 - +5 V

+12V 0 - +7 V 0 - +5 V

-12V 0 - +7 V 0 - +5 V

PM1 Temparature

-50C - +50C 0 - +5 V

PM2 Temparature

-50C - +50C 0 - +5 V

CNT Temparature

-50C - +50C 0 - +5 V

CH_A High Voltage

-1,250C - 0 V 0 - +5 V

CH_B High Voltage

-1,250C - 0 V 0 - +5 V

Analog Signal Interface

Power Requirements

Supply Voltage from the ISUAL : +28V +7/-6VPower Dissipation : 16.4W (observation), 12.6W(stand-by)

PCB P1&2 223 mW

PCB P3&4 2,623 mW

PCB P5 5,311 mW

DC/DC Conv. 1,600 mW

HV PS 3,800 mW ( 0 mW @stand-by)

Environmental Testsbefore delivery to UCB

- Thermal Cycling Ambient Pressure Test

- Random Vibration Test

- Shock Test

-Vacuum Test (at Ambient Temp)

-EMC/EMI :

conducted emission on power lines test only

Wavelength range

Max sensitivity wavelength:

405 nm (blue) 550 nm(red)

1 % bandwidth of max sensitivity:

340-470 nm 520-810 nm

Electron Counts

where fc(LPF)=10kHz

equivalent SQRT(dark counts) ~ 0.65 [electrons/0.1ms]

for 30 MR sprites with 50 km width at 2500 km range

red @700 nm 15.3 [electrons/0.1ms]

blue @400 nm 38.4 [electrons/0.1ms]

SNR 15.3/0.65 = 24

38.4/0.65 = 59

for 10 MR elves with 400 km width ar 2500 km range

red @700 nm 42 [electrons/0.1ms]

blue @400 nm 300 [electrons/0.1ms]

SNR 42/0.65 = 64

300/0.65 = 460

10 kR aurora/airglow

where fc(LPF) = 100 Hz

equivalent SQRT(dark counts) ~ 6.5 [electrons/0.01s]

200 [electrons/10 ms] @550 nm

SNR 200/6.5 = 30

Mounting Interface Temperature Limits

Mass of Electronic Board

P1&&2: 200 g, P3&4: 350 g, P5: 350 g

HV PS: 140 g, DC/DC: 30 g, LineFilter: 50 g

Operating Temperatures

Non-operating Temperatures

-20℃ 　 to 　 +30℃

-35 to +50℃ ℃