Rainbow Electronics DS4520 User Manual
General description, Applications, Features
General Description
The DS4520 is a 9-bit nonvolatile (NV) I/O expander with
64 bytes of NV user memory controlled by an I
2
C
TM
-
compatible serial interface. The DS4520 offers users a
digitally programmable alternative to hardware jumpers
and mechanical switches that are being used to control
digital logic nodes. Furthermore, the digital state of each
pin can be read through the serial interface. Each I/O
pin is independently configurable. The outputs are open
drain with selectable pullups. Each output has the ability
to sink up to 12mA. 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 Input/Output Pins
♦ 64-Byte NV User Memory (EEPROM)
♦ I
2
C-Compatible Serial Interface
♦ Up to 8 Devices Can be Multidropped on the
Same I
2
C Bus
♦ Open-Drain Outputs with Configurable Pullups
♦ Outputs Capable of Sinking 12mA
♦ Low Power Consumption
♦ Wide Operating Voltage (2.7V to 5.5V)
♦ Operating Temperature Range: -40°C to +85°C
DS4520
9-Bit I
2
C Nonvolatile
I/O Expander Plus Memory
______________________________________________ Maxim Integrated Products
1
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
I/O_0
GND
I/O_8
I/O_7
I/O_6
I/O_5
A2
SCL
SDA
TOP VIEW
I/O_1
I/O_2
A0
I/O_3
I/O_4
A1
V
CC
DS4520
Pin Configuration
SCL
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
SDA
A0
A1
A2
GND
FROM
SYSTEM
CONTROLLER
FPGA
CLOCK
GENERATOR
CPU
SPEED
SELECT
4.7kΩ
4.7kΩ
0.1µF
V
CC
V
CC
DS4520
Typical Operating Circuit
Rev 0; 6/04
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.
Add “/T&R” for tape and reel orders.
Ordering Information
I
2
C is a trademark of Philips Corp. Purchase of I
2
C components from Maxim Integrated Products, Inc., or one of its sublicensed
Associated Companies, conveys a license under the Philips I
2
C Patent Rights to use these components in an I
2
C system, provided
that the system conforms to the I
2
C Standard Specification as defined by Philips.
PART
TEMP RANGE
PIN-PACKAGE
DS4520E
-40°C to +85°C
16 TSSOP