First Test Results of the prototype sensor AROM-1
Christine Hu-Guo (on behalf of the PICSEL & ALICE teams of IPHC-Strasbourg)
OUTLINE Reminder: variants of in-pixel circuitry with
discriminator developed Status of AROM-1 A,B,C lab. tests Summary and provisional conclusion
IPHC [email protected] 2ITS mini week 10-12/3 2014
AROM (Accelerated Readout MIMOSA Sensor) Family
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VERSION 1 VERSION 2 VERSION 3
AROM-0 submission Feb. 2013
• 32 x32 pixels (22x33 µm²) Single row readout
AROM-1 submission Aug. 2013• Optimising thermal noise• Minimising RTS noise by increasing input NMOS dimension• Minimising cross talk by optimising layout
64 x 64 pixels, double row readoutA: 22x33 µm² (same layout as AROM-0_V2)B: 22x33 µm² (different layout)C: 24x33 µm² (study impact of pixel pitch)
AROM-1 submission Jan. 2014• Optimising power consumption• Optimising input transistor dimension• Minimising cross talk coming from Latch
64 x 64 pixels, double row readoutE: 22x33 µm² F: 27x27 µm² FSBB-A0 submission Feb. 2014
• Increasing digital signal driving capability
Pixel array: 416 x 416 pixelsPixel pitches: 22x33 µm²
ASTRAL sensor
• 32 x32 pixels (22x33 µm²) Single row readout• 16 x16 pixels (22x33 µm²) Double row
readout
• 32 x32 pixels (22x33 µm²) Single row readout
IPHC [email protected] 3ITS mini week 10-12/3 2014
Status of test
Beginning of Jan. 2014: AROM-1 A, B, C back from foundry 09/01/2014: DAQ + JTAG validation 20/01/2014: analysis software validation
Stand by due to other activities (AIDA test, ER preparation)
18/2/2014: early characterisations Test condition:
15 °C Clock frequency @ 100 MHz
160 MHz in the design. CK @ 100 MHz is limited by present acquisition board New acquisition board is being validated for full speed operation
IPHC [email protected] 4ITS mini week 10-12/3 2014
AROM-1 (A, B, C) submission Aug. 2013
Array: 64 x 64 pixels, 56 digital output columns, 8 analogue + digital output columns Two rows are read out simultaneously every 100 ns
2 x 64 digital signals are multiplexed to x16 outputs at 80 MHz 2 x 8 analogue signals have each an individual output buffer
Testability: Analogue (diode + preamplifier) behaviours: Digital output:
Scan discriminator alone Scan discriminator with FE (sensing element + preamplifier)
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Ana. TestOnly for 8Analogue channels
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IPHC [email protected] 5ITS mini week 10-12/3 2014
Analogue output (1) Tests performed with Fe55 source
Charge collected by seed pixel and by 2x2 pixels Seed pixel collects ~30-40 % of total charge similar to CCE of MIMOSA-22THRB
IPHC [email protected] 6ITS mini week 10-12/3 2014
Analogue output (2)
Impact of the discriminator control signal on analogue part behaviour
Conclusion: marginal impact
Analogue part of the circuitry shows satisfactory performances
IPHC [email protected] 7ITS mini week 10-12/3 2014
Digital output: Test discriminator alone
Tests performed by scanning Test_Sig voltage Chip A:
TN ~ 0.65 mV, FPN ~ 0.55 mV Consistent with MIMOSA-22THRB
IPHC [email protected] 8ITS mini week 10-12/3 2014
Digital output: Test discriminator connected to FE (1)
Chip A TN ~ 0.61 mV, FPN ~ 0.49 mV TN dispersion X2
IPHC [email protected] 9ITS mini week 10-12/3 2014
Digital output: Test discriminator connected to FE (2)
Results from chip B (same as chip A but different layout):
Discriminator alone Discriminator + FE
TN ~ 0.61 mV, FPN ~ 0.47 mV TN ~ 0.75 mV, FPN ~ 0.48 mV
IPHC [email protected] 10ITS mini week 10-12/3 2014
Test of (Sensing element + Amp + Discriminator) with Fe55
Individual tests of pixel (analogue) or discriminator (S curve) are correct
Analogue part is sensitive to Fe55 source, number of hits is as expected
Pixel + discriminator exhibit currently a too low sensitivity to the source AROM-0 does not show such a feature Need still some time to check reliability of measurement
Verifying control signals, bias, … Using external reference voltage Studying power supply dependency
IPHC [email protected] 11ITS mini week 10-12/3 2014
Summary and Provisional Conclusion
Tests of AROM-1, which prefigurates the ASTRAL pixel (in-pixel discriminator), have started a few weeks ago
Individual studies of the analogue part of the circuitry and of the discrimination circuitry show satisfactory performances
Once both parts are interconnected, the pixel seems to lose detection efficiency, in a way which is not yet understood
More time is needed to cross-check the set-up
Forthcoming steps: clarify the behaviour of the pixel Move to nominal frequency (160 MHz) April : start testing AROM-1E/F ?
