General Description

The DS4550 is a 9-bit, nonvolatile (NV) I/O expander

with 64 bytes of NV user memory controlled by either

JTAG port. The DS4550 offers a digitally programmable

alternative to hardware jumpers and mechanical

switches that are being used to control digital logic

nodes. Each I/O pin is independently configurable. The

outputs are open drain with selectable pullups. Each

output has the ability to sink up to 16mA, and since the

device is NV, it powers up in the desired state allowing

it to control digital logic inputs immediately on power-

up without having to wait for the host CPU to initiate

control.

Applications

RAM-Based FPGA Bank Switching for Multiple

Profiles

Selecting Between Boot Flash

Setting ASIC Configurations/Profiles

Servers

Network Storage

Routers

Telecom Equipment

PC Peripherals

Features

♦ Programmable Replacement for Mechanical

Jumpers and Switches

♦ Nine NV Inputs/Outputs

♦ 64-Byte NV User Memory (EEPROM)

♦ Up to 8 Devices can be Multidropped on the Same

♦ IEEE 1149.1 Boundary Scan Compliant

♦ Open-Drain Outputs with Configurable Pullups

♦ Outputs Capable of Sinking 16mA

♦ Low Power Consumption

♦ Wide Operating Voltage Range: 2.7V to 5.5V

♦ Operating Temperature Range: -40°C to +85°C

Expander Plus Memory

______________________________________________ Maxim Integrated Products

1

20

19

18

17

16

15

14

13

1

2

3

4

5

6

7

8

GND

I/O_8

I/O_7

I/O_6

I/O_3

I/O_2

I/O_1

I/O_0

TOP VIEW

I/O_5

A2

TDO

TDI

TCK

A1

A0

I/O_4

12

11

9

10

SCL

SDA

TMS

TSSOP

DS4550

FPGA

CLOCK

GENERATOR

CPU SPEED

SELECT

A0

A1

A2

GND

0.1µF

4.7k

INTERFACE

JTAG

INTERFACE

DS4550

SCL

SDA

TCK

TMS

TDI

TDO

I/O_0

I/O_1

I/O_2

I/O_3

I/O_4

I/O_5

I/O_6

I/O_7

I/O_8

Pin Configuration

Typical Operating Circuit

Rev 0; 9/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Ordering Information

PART

TEMP RANGE

PIN-PACKAGE

DS4550E

-40°C to +85°C

20 TSSOP

Add “/T&R” for tape and reel orders.