Rainbow Electronics DS4520 User Manual
General Description
The DS4520 is a 9-bit nonvolatile (NV) I/O expander with
64 bytes of NV user memory controlled by an I2CTMcompatible 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 I2C 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
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 I
2
C Patent Rights to use these components in an I2C 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
DS4520
9-Bit I2C Nonvolatile
I/O Expander Plus Memory
2 _____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(TA= -40°C to +85°C)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Voltage on VCC, SDA, and SCL Pins
Relative to Ground.............................................-0.5V to +6.0V
Voltage on A0, A1, A2, and I/O_n [n = 0 to 8]
Relative to Ground....-0.5V to (V
CC
+ 0.5V) not to exceed +6.0V
Operating Temperature Range ...........................-40°C to +85°C
EEPROM Programming Temperature Range .........0°C to +70°C
Storage Temperature Range .............................-55°C to +125°C
Soldering Temperature ...See IPC/JEDEC J-STD-020A Specification
PARAMETER
CONDITIONS MIN TYP MAX UNITS
Supply Voltage V
CC
(Note 1) +2.7 +5.5 V
Input Logic 1 V
IH
V
Input Logic 0 V
IL
-0.3
V
DC ELECTRICAL CHARACTERISTICS
(VCC= +2.7V to +5.5V; TA= -40°C to +85°C, unless otherwise noted.)
PARAMETER
CONDITIONS MIN TYP MAX UNITS
Standby Current I
STBY
(Note 2) 2 10 µA
Input Leakage I
L
-1.0 +1.0 µA
Input Current each I/O Pin I
I/O
0.4V < V
I/O
< 0.9VCC (Note 3) -1.0 +1.0 µA
3mA sink current 0 0.4
Low-Level Output Voltage (SDA)
6mA sink current 0 0.6
V
I/O Pin Low-Level Output Voltage
12mA sink current 0.4 V
I/O Pin Pullup Resistors R
PU
4.0 5.5 7.5 kΩ
I/O Capacitance C
I/O
(Note 4) 10 pF
Power-On Reset Voltage V
POR
1.6 V
SYMBOL
SYMBOL
V
OL SDA
V
OL I/O
0.7 x V
CC
V
CC
0.3 x V
+ 0.3
CC
DS4520
9-Bit I2C Nonvolatile
I/O Expander Plus Memory
_____________________________________________________________________ 3
Note 1: All voltages referenced to ground.
Note 2: I
STBY
is specified with SDA = SCL = VCC, outputs floating, and inputs connected to VCCor GND.
Note 3: The DS4520 does not obstruct the SDA and SCL lines if V
CC
is switched off as long as the voltages applied to these inputs
do not violate their minimum and maximum input voltage levels.
Note 4: Guaranteed by design.
Note 5: Timing shown is for fast-mode (400kHz) operation. This device is also backward compatible with I
2
C standard-mode timing.
Note 6: C
B
—total capacitance of one bus line in picofarads.
Note 7: EEPROM write time applies to all the EEPROM memory and SRAM shadowed EEPROM memory when SEE = 0. The EEPROM
write time begins after a stop condition occurs.
AC ELECTRICAL CHARACTERISTICS (See Figure 2)
(VCC= +2.7V to +5.5V; TA= -40°C to +85°C, unless otherwise noted. Timing referenced to V
IL(MAX)
and V
IH(MIN)
.)
PARAMETER
SYMBOL
CONDITIONS MIN TYP MAX UNITS
SCL Clock Frequency f
SCL
(Note 5) 0 400 kHz
Bus Free Time Between Stop and
Start Conditions
t
BUF
1.3 µs
Hold Time (Repeated) Start
Condition
0.6 µs
Low Period of SCL t
LOW
1.3 µs
High Period of SCL t
HIGH
0.6 µs
Data Hold Time
0 0.9 µs
Data Setup Time
100 ns
Start Setup time
0.6 µs
SDA and SCL Rise Time t
R
(Note 6) 20 + 0.1C
B
300 ns
SDA and SCL Fall Time t
F
(Note 6) 20 + 0.1C
B
300 ns
Stop Setup Time
0.6 µs
SDA and SCL Capacitive Loading
C
B
(Note 6) 400 pF
EEPROM Write Time t
WR
(Note 7) 10 20 ms
NONVOLATILE MEMORY CHARACTERISTICS
(VCC= +2.7V to +5.5V, unless otherwise noted.)
PARAMETER
CONDITIONS MIN TYP MAX UNITS
EEPROM Writes +70°C (Note 4)
t
HD:STA
t
HD:DAT
t
SU:DAT
t
SU:STA
t
SU:STO
SYMBOL
50,000
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