Digital control board debugging notes - Revision history

Senderovich at 15:38, 30 September 2010

2010-09-30T15:38:36Z

2010-03-30T19:51:17Z

2009-11-05T15:12:04Z

Incorrect footprint for the Ethernet Jack used: added info about part numbers

2009-10-29T18:32:49Z

2009-10-29T18:32:15Z

2009-10-21T23:38:41Z

Wrong polarity of Zener Diode on -5V

2009-10-19T12:12:15Z

Mismatched JTAG programming header =

2009-10-19T12:11:56Z

2009-10-13T19:20:11Z

2009-07-26T08:43:23Z

Description

← Older revision		Revision as of 15:38, 30 September 2010
Line 1:		Line 1:
	This page contains a list of all currently known problems with the digital control board.		This page contains a list of all currently known problems with the digital control board.
		+
		+	== Resistor on DAC temperature measurement diode too high ==
		+	=== Description ===
		+	When the readout is programmed using the DAC manual's coefficients and offset, the temperature value ends up tens of degrees off.
		+
		+	=== Cause/Solution ===
		+	The board was designed with R1=270kΩ to sink the current from the DAC's internal temperature-measuring diode to ground. The manual specifies the expected diode drop at 25degC will be 0.65V at a current of 100uA. Given the sensitivity of this device (with a coefficient of 2.2mV/degC) it is seems best to match their measurement conditions and adjust the resistor so that 0.65V drop from the biasing 5V results in 100uA through the resistor. So, ''R1 should be set to 43.5kΩ''.
		+
		+	Three parallel resistors have been soldered into place on the prototype board providing a nominal R1 of 43.6kΩ. The readout values are now reasonable.
		+

	== No Power on +1.2V Power Island ==		== No Power on +1.2V Power Island ==

← Older revision		Revision as of 19:51, 30 March 2010
Line 1:		Line 1:
	This page contains a list of all currently known problems with the digital control board.		This page contains a list of all currently known problems with the digital control board.
−
−	~~= Problems =~~

	== No Power on +1.2V Power Island ==		== No Power on +1.2V Power Island ==

@@ Line 68: / Line 68: @@
-== Incorrect footprint for the Ethernet Jack used ==
+== Ethernet jack pinout mismatch  ==
 = Suggested/Preferred Changes =
 * <code>R12</code>, the pull-up resistor for the reset pins (header 2) is unnecessary, as the FPGA pin can be programmed to pull up.

← Older revision		Revision as of 18:32, 29 October 2009
Line 76:		Line 76:
	= Suggested/Preferred Changes =		= Suggested/Preferred Changes =

−	<code>R12</code>, the pull-up resistor for the reset pins (header 2) is unnecessary, as the FPGA pin can be programmed to pull up.	+	* <code>R12</code>, the pull-up resistor for the reset pins (header 2) is unnecessary, as the FPGA pin can be programmed to pull up.

@@ Line 1: / Line 1: @@
 This page contains a list of all currently known problems with the digital control board.
 == No Power on +1.2V Power Island ==
@@ Line 57: / Line 58: @@
 === Other Details and Current Status ===
 This problem may be related to the overload on the -5V circuitry for of the DAC.
 == Mismatched JTAG programming header ==
@@ Line 64: / Line 66: @@
 === Solution ===
 For the testing stage, the flying lead connector is sufficient to bypass this problem. The layout must be corrected to the matching header (type?). Change entered already?

@@ Line 59: / Line 59: @@
-== Mismatched JTAG programming header ===
+== Mismatched JTAG programming header ==
 === Description ===
 The connector of the "Xilinx Platform USB II" kit seems to be a reduced size compared to the standard 0.1" spaced pin header with which the board is equipped.

← Older revision		Revision as of 12:11, 19 October 2009
Line 49:		Line 49:

	== Wrong polarity of Zener Diode on -5V ==		== Wrong polarity of Zener Diode on -5V ==
		+	=== Description ===
		+	Zener diode D2 is reversed in the layout. It is correct in the schematics.
		+
		+	=== Solution ===
		+	The diode was rotated on all the prototyping boards. This indications has '''not yet been entered into the layout'''.
		+
		+	=== Other Details and Current Status ===
		+	This problem may be related to the overload on the -5V circuitry for of the DAC.
		+

−	~~Zener diode D2~~ is ~~reversed in~~ the layout~~. It is correct in~~ the ~~schematics~~.	+	== Mismatched JTAG programming header ===
		+	=== Description ===
		+	The connector of the "Xilinx Platform USB II" kit seems to be a reduced size compared to the standard 0.1" spaced pin header with which the board is equipped.
		+
		+	=== Solution ===
		+	For the testing stage, the flying lead connector is sufficient to bypass this problem. The layout must be corrected to the matching header (type?). Change entered already?

@@ Line 1: / Line 1: @@
 This page contains a list of all currently known problems with the digital control board.
 == No Power on +1.2V Power Island ==
@@ Line 15: / Line 16: @@
 * June 22, 2009: One board has been modified to correct this problem.
 == SPI Bus Miswired ==
@@ Line 30: / Line 32: @@
 This modification has been implemented.
 == Incorrect Oscillator ==
@@ Line 43: / Line 46: @@
 This modification has been implemented.