Файл:AD546.pdf

Материал из РадиоВики - энциклопедии радио и электроники
Перейти к: навигация, поиск
Ссылка на страницу индекса

AD546 Circuit Board Notes

The AD546 is designed for through hole mount into PC boards. Maintaining picoampere level resolution in that environment requires a lot of care. Since both the printed circuit board and the amplifier’s package have a finite resistance, the voltage difference between the amplifier’s input pin and other pins (or traces on the PC board) will cause parasitic currents to flow into (or out of) the signal path (see Figure 26). These currents can easily exceed the 1 pA input current level of the AD546 unless special precautions are taken. Two successful methods for minimizing leakage are guarding the AD546’s input lines and maintaining adequate insulation resistance. The AD546’s positive input (Pin 3) is located next to the negative supply voltage pin (Pin 4). The negative input (Pin 2) is next to the balance adjust pin (Pin 1) which is biased at a potential close to the negative supply voltage. The layouts shown in Figures 27a and 27b for the inverter and follower connections will guard against the effects of low surface resistance of the board. Note that the guard traces should be placed on both sides of the board. In addition the input trace should be guarded on both of its edges along its entire length.

Figure 26. Sources of Parasitic Leakage Currents

Figure 27a. Guarding Scheme—Inverter

Figure 27b. Guarding Scheme—Follower

REV. A

–7–


1 2 3 4 5 6 7 8 9 10 11 12
Перейти на страницу


Исходный файл(2550 × 3300 пикселей, размер файла: 456 КБ, MIME-тип: application/pdf, 12 страниц)

Importing file

История файла

Нажмите на дату/время, чтобы просмотреть, как тогда выглядел файл.

Дата/времяМиниатюраРазмерыУчастникПримечание
текущий16:48, 19 мая 2014Миниатюра для версии от 16:48, 19 мая 20142550 × 3300, 12 страниц (456 КБ)Maintenance script (обсуждение)Importing file
  • Вы не можете перезаписать этот файл.

Нет страниц, ссылающихся на данный файл.

Метаданные