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: -40C to +85C
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
4.7k
4.7k
0.1F
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
-40C to +85C
16 TSSOP
DS4520
9-Bit I
2
C Nonvolatile
I/O Expander Plus Memory
2
_____________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
RECOMMENDED DC OPERATING CONDITIONS
(T
A
= -40C to +85C)
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 V
CC
, 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 ...........................-40C to +85C
EEPROM Programming Temperature Range .........0C to +70C
Storage Temperature Range .............................-55C to +125C
Soldering Temperature ...See IPC/JEDEC J-STD-020A Specification
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Supply Voltage
V
CC
(Note 1)
+2.7
+5.5
V
Input Logic 1
V
IH
0.7 x V
CC
V
CC
+ 0.3
V
Input Logic 0
V
IL
-0.3
0.3 x V
CC
V
DC ELECTRICAL CHARACTERISTICS
(V
CC
= +2.7V to +5.5V; T
A
= -40C to +85C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Standby Current
I
STBY
(Note 2)
2
10
A
Input Leakage
I
L
-1.0
+1.0
A
Input Current each I/O Pin
I
I/O
0.4V < V
I/O
< 0.9V
CC
(Note 3)
-1.0
+1.0
A
3mA sink current
0
0.4
Low-Level Output Voltage (SDA)
V
OL SDA
6mA sink current
0
0.6
V
I/O Pin Low-Level Output Voltage
V
OL I/O
12mA sink current
0.4
V
I/O Pin Pullup Resistors
R
PU
4.0
5.5
7.5
k
I/O Capacitance
C
I/O
(Note 4)
10
pF
Power-On Reset Voltage
V
POR
1.6
V
DS4520
9-Bit I
2
C Nonvolatile
I/O Expander Plus Memory
_____________________________________________________________________
3
Note 1: All voltages referenced to ground.
Note 2: I
STBY
is specified with SDA = SCL = V
CC
, outputs floating, and inputs connected to V
CC
or 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)
(V
CC
= +2.7V to +5.5V; T
A
= -40C to +85C, 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
s
Hold Time (Repeated) Start
Condition
t
HD:STA
0.6
s
Low Period of SCL
t
LOW
1.3
s
High Period of SCL
t
HIGH
0.6
s
Data Hold Time
t
HD:DAT
0
0.9
s
Data Setup Time
t
SU:DAT
100
ns
Start Setup time
t
SU:STA
0.6
s
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
t
SU:STO
0.6
s
SDA and SCL Capacitive Loading
C
B
(Note 6)
400
pF
EEPROM Write Time
t
WR
(Note 7)
10
20
ms
NONVOLATILE MEMORY CHARACTERISTICS
(V
CC
= +2.7V to +5.5V, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
EEPROM Writes
+70C (Note 4)
50,000
DS4520
9-Bit I
2
C Nonvolatile
I/O Expander Plus Memory
4
_____________________________________________________________________
Typical Operating Characteristics
(V
CC
= +5.0V, T
A
= +25C, unless otherwise noted.)
SUPPLY CURRENT vs. SUPPLY VOLTAGE
DS4520 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (
A)
4.5
4.0
3.5
0.5
1.0
1.5
2.0
0
3.0
5.0
I/O0I/O7 CONTROL BITS = 0
I/O0I/O7 PULLUPS DISABLED
V
CC
= SDA = SCL
SUPPLY CURRENT vs. TEMPERATURE
DS4520 toc02
TEMPERATURE (C)
SUPPLY CURRENT (
A)
80
60
40
20
0
-20
0.5
1.0
1.5
2.0
2.5
0
-40
I/O0I/O7 CONTROL BITS = 0
I/O0I/O7 PULLUPS DISABLED
V
CC
= SDA = SCL = 5V
SUPPLY CURRENT vs. SCL FREQUENCY
DS4520 toc03
SCL FREQUENCY (kHz)
SUPPLY CURRENT (
A)
300
200
100
2
4
6
8
10
12
14
16
18
20
0
0
400
V
CC
= SDA = 5V
I/O OUTPUT VOLTAGE
vs. SUPPLY VOLTAGE
DS4520 toc04
SUPPLY VOLTAGE (V)
I/O VOLTAGE (V)
5
4
3
2
1
1
2
3
4
5
6
0
0
6
PULLUPS ENABLED
PULLDOWNS DISABLED
HIGH IMPEDANCE
EEPROM RECALL AT V
POR
DS4520
9-Bit I
2
C Nonvolatile
I/O Expander Plus Memory
_____________________________________________________________________
5
Pin Description
PIN
NAME
FUNCTION
1
I/O_0
Input/Output 0. Bidirectional I/O pin.
2
I/O_1
Input/Output 1. Bidirectional I/O pin.
3
I/O_2
Input/Output 2. Bidirectional I/O pin.
4
I/O_3
Input/Output 3. Bidirectional I/O pin.
5
I/O_4
Input/Output 4. Bidirectional I/O pin.
6
A0
I
2
C Address Input. Inputs A0, A1, and A2 determine the I
2
C slave address of the device.
7
A1
I
2
C Address Input. Inputs A0, A1, and A2 determine the I
2
C slave address of the device.
8
V
CC
Power-Supply Voltage
9
SDA
I
2
C Serial Data Open-Drain Input/Output
10
SCL
I
2
C Serial Clock Input
11
A2
I
2
C Address Input. Inputs A0, A1, and A2 determine the I
2
C slave address of the device.
12
I/O_5
Input/Output 5. Bidirectional I/O pin.
13
I/O_6
Input/Output 6. Bidirectional I/O pin.
14
I/O_7
Input/Output 7. Bidirectional I/O pin.
15
I/O_8
Input/Output 8. Bidirectional I/O pin.
16
GND
Ground
DS4520
I/O CONTROL
REGISTERS
I/O CELL (x9)
I/O_n
[n = 0 TO 8]
R
PU
PULLUP ENABLE (F0h-F1h)
I/O CONTROL (F2h-F3h)
I/O STATUS (F8h-F9h)
I
2
C
INTERFACE
SDA
SCL
A0
A1
A2
GND
EEPROM
64 BYTES
USER MEMORY
[00h TO 3Fh]
V
CC
V
CC
V
CC
Block Diagram
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