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AR# 39045

Spartan-6 XPE - Changes made for XPE 12.3.1 update

Description

The XPE Spreadsheet 12.3.1 includes Spartan-6 FPGA quiescent power reductionsas explained in the answer record. It also includesa few exceptions which are noted below but are expected to have little or no overall impact.

Solution

The maximum quiescent power is being reduced by 30% or more for Spartan-6 FPGA, across all devices that are currently in production. This does not affect the typical quiescent numbers seen in the data sheet, but is reflected in the power estimators, starting with XPE 12.3.1 which was posted in late November. The new values are applicable to all devices, including those already shipped.

Although every production device has a net reduction in total quiescent current and power, the LX100/T and LX150/T have a small increase on the VCCAUX rail, offset by a much larger decrease on the VCCINT rail. For the LX150/T, ICCAUXQ max for the -3I speed grade is being increased from 172 mA to 234 mA. That small62 mA increase is offset by a >900 mA decrease in ICCINTQ max, which results in a net power reduction of almost 30%. With the relatively small increase in ICCAUXQ compared to the overall power reduction, we do not expect this to be a problem, but we want to make surethe change is noted.

The LX150T -4C speed grade has a similar change, but with lower current due to the lower max temperature. The LX100/T has an even smaller increase in ICCAUXQ of only 10 mA for the -3I, offset by a 560 mA decrease in ICCINTQ. Note that the LX150/T -2 speed grade currently has a higher ICCAUXQ at 279 mA, and it is also changing to 234 mA, which means that the -2 gets a reduction on both the VCCAUX and VCCINT rails and a net 42% power reduction overall. All Spartan-6 -2 speed grade devices in production are being reduced a similar amount, making the power consumption consistent across the -2/-3/-4 speed grades. The Lower Power Spartan-6 (-1L) numbers are also being adjusted in anticipation of future production, but the net power stays about the same, and is >40% lower than the standard voltage devices.

The changes are seen in XPE only in the Device Static current and only when Maximum Process is selected. The maximum numbers noted here are for the highest Industrial temperature (TJ=100C) and the highest VCC ranges (VCCINT=1.26V and VCCAUX=3.45V). Quiescent current will have similar percentage changes for other conditions, including Commercial. Dynamic current does not change, but the total current will be lower due to the lower quiescent starting point. Typical process power, at any condition, does not change.

The Spartan-6 LX4 and LX9 devices are being updated similarly, with a small2 mA increase on max ICCAUXQ offset by a much larger 33 mA decrease on ICCINTQ. With these devices just going to production, refer to the new XPE 12.3.1 to get the correct values.

The reductions restore the LX16 and LX45 to levels at or below the values they had before they were increased in the MCB Performance PCN, XCN10024.

The table below summarizes the changes for the Spartan-6 family. The Virtex-6 family is also being reduced across the board, by 12%, refer to XPE for those numbers.


Device

ICCINTQ max
(mA)

ICCAUXQ max (mA)

Total Quiescent Power max (mW)

Old

New

Old

New

Old

New

Improvement

-2I

-3I

-2I, -3I

-2I

-3I

-2I, -3I

-2I

-3I

-2I, -3I

-2I

-3I

LX4

142*

142*

109

11*

11*

13

216*

216*

181

16%

16%

LX9

142*

142*

109

11*

11*

13

216*

216*

181

16%

16%

LX16

228

228

155

25

17

15

374

346

245

34%

29%

LX25/T

429

372

250

43

28

25

689

564

400

42%

29%

LX45/T

788

684

460

79

49

45

1264

1033

734

42%

29%

LX75/T

1335

1167

790

140

87

76

2167

1772

1258

42%

29%

LX100/T

1846

1580

1020

170

118

128

2913

2398

1728

41%

28%

LX150/T

2642

2306

1400

279

172

234

4293

3500

2573

40%

26%




* Old specs for LX4 and LX9 were pre-production






AR# 39045
Date Created 12/03/2010
Last Updated 12/15/2012
Status Active
Type General Article
Devices
  • Spartan-6 LX
  • Spartan-6 LXT