CATHODE

1

NC

2

NC

3

4

8

7

NC

6

ANODE

5

NC

Rsup

Vsup

GND

NC

NC

GND

LM285-1.2, LM385-1.2, LM385B-1.2

www.ti.com

SLVS075J – APRIL 1989 – REVISED JANUARY 2015

10 Power Supply Recommendations

In order to not exceed the maximum cathode current, be sure that the supply voltage is current limited.

For applications shunting high currents (30 mA max), pay attention to the cathode and anode trace lengths,

adjusting the width of the traces to have the proper current density.

11 Layout

11.1 Layout Guidelines

•

Connect a low-ESR, 0.1-

•

Decouple other active devices in the system per the device specifications.

•

Using a solid ground plane helps distribute heat and reduces electromagnetic interference (EMI) noise pickup.

•

Place the external components as close to the device as possible. This configuration prevents parasitic errors

(such as the Seebeck effect) from occurring.

•

Do not run sensitive analog traces in parallel with digital traces. Avoid crossing digital and analog traces if

possible and only make perpendicular crossings when absolutely necessary.

11.2 Layout Example

Figure 12. Layout Diagram

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Product Folder Links: LM285-1.2 LM385-1.2 LM385B-1.2