AS1700-NPN Просмотр технического описания (PDF) - Astec Semiconductor => Silicon Link

Номер в каталоге

Компоненты Описание

производитель

AS1700-NPN

Semicustom Bipolar Array

Astec Semiconductor => Silicon Link 

AS17xx

Semicustom Bipolar Array

Functional Circuit Blocks

Trimming Schemes

There often arises the need to trim a parameter (i.e. voltage, current, oscillator frequency, offset null,

etc.) to some particular value because of processing variations involved with wafer fabrication. We

have developed two methods to accomplish this goal: 1) fuse link, where a fuse is blown to cause

an open; and 2) zener zap, where a zener is taken well into breakdown until a short occurs.

Fuse Link

Fuse links can be used similar to zeners for trimming, but the fuses must be located on a bonding

pad inside the pad cut because a fuse won’t blow if there is passivation over it. One possible trim

scheme using fuse links is shown below.

Metal Trace

To Circuit

Fuse Link

Pad

Zener Zap

Figure 12.

Figure 13.

When using zener zap trim methods there are several points to keep in mind: the zener should be

located near a pad, no cross-unders should be used to connect the zener with the pad, and the metal

lines connecting the pad to the zener should be as thick as possible to allow the high current

necessary to blow the zener. A few examples of the many possible trim schemes are shown in

Figure 14, Figure 15 and Figure 16.

Figure 14. Simple Trim Setup

with 8 Trim Steps.

ASTEC Semiconductor

Figure 15. Trim Scheme Using Only 3

Pads to Get 16 Trim Steps.

134

Figure 16. Parallel Trim Scheme

with 8 Trim Steps.

Share Link: