DS4550 Datasheet, PDF (1/18 Pages) Dallas Semiconductor – I2C and JTAG Nonvolatile 9-Bit I/O Expander Plus Memory

Rev 0; 9/04
I²C and JTAG Nonvolatile 9-Bit I/O
Expander Plus Memory
General Description
The DS4550 is a 9-bit, nonvolatile (NV) I/O expander
with 64 bytes of NV user memory controlled by either
an I²C^TM-compatible serial interface or an IEEE 1149.1
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
Pin Configuration
Features
♦ Programmable Replacement for Mechanical
Jumpers and Switches
♦ Nine NV Inputs/Outputs
♦ 64-Byte NV User Memory (EEPROM)
♦ I²C-Compatible Serial Interface and JTAG
♦ Up to 8 Devices can be Multidropped on the Same
I²C Bus
♦ 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
Ordering Information
PART
DS4550E
TEMP RANGE
-40°C to +85°C
Add “/T&R” for tape and reel orders.
PIN-PACKAGE
20 TSSOP
Typical Operating Circuit
TOP VIEW
V_CC
I/O_0 1
I/O_1 2
I/O_2 3
I/O_3 4
I/O_4 5
A0 6
A1 7
TCK 8
TMS 9
V_CC 10
DS4550
20 GND
19 I/O_8
18 I/O_7
17 I/O_6
16 I/O_5
15 A2
14 TDO
13 TDI
12 SCL
11 SDA
0.1µF
4.7k
I²C
INTERFACE
JTAG
INTERFACE
V_CC ^DS4550 _{I/O_0}
A0
I/O_1
A1
I/O_2
A2
I/O_3
GND
I/O_4
I/O_5
SCL
I/O_6
SDA
I/O_7
TCK
I/O_8
TMS
TDI
TDO
FPGA
CLOCK
GENERATOR
CPU SPEED
SELECT
TSSOP
I²C is a trademark of Philips Corp. Purchase of I²C components from Maxim Integrated Products, Inc., or one of its sublicensed
Associated Companies, conveys a license under the Philips I²C Patent Rights to use these components in an I²C system, provided
that the system conforms to the I²C Standard Specification as defined by Philips.
______________________________________________ Maxim Integrated Products 1
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.