General Description
The MAX6953 is a compact cathode-row display driver
that interfaces microprocessors to 5
7 dot-matrix LED
displays through an I
2
CTM-compatible serial interface.
The MAX6953 drives up to four digits (140 LEDs).
Included on-chip are an ASCII 104-character font, mul-
tiplex scan circuitry, column and row drivers, and static
RAM that stores each digit, as well as font data for 24
user-definable characters. The segment current for the
LEDs is set by an internal digit-by-digit digital bright-
ness control.
The device includes a low-power shutdown mode, seg-
ment blinking (synchronized across multiple drivers, if
desired), and a test mode that forces all LEDs on. The
LED drivers are slew-rate limited to reduce EMI.
For an SPITM-compatible version, refer to the MAX6952
data sheet. An EV kit is available for the MAX6952.
Applications
Message Boards
Medical Equipment
Industrial Displays
Audio/Video Equipment
Gaming Machines
Features
o 400kbps 2-Wire Interface Compatible with I
2
C
o 2.7V to 5.5V Operation
o Drives 4 Monocolor or 2 Bicolor Cathode-Row
5
7 Matrix Displays
o Built-In ASCII 104-Character Font
o 24 User-Definable Characters Available
o Automatic Blinking Control for Each Segment
o 70µA Low-Power Shutdown (Data Retained)
o 16-Step Digital Brightness Control
o Display Blanked on Power-Up
o Slew-Rate-Limited Segment Drivers for Lower EMI
o 36-Pin SSOP and 40-Pin DIP Packages
o Extended Temperature Range as Standard
MAX6953
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
7
Matrix LED Display Driver
________________________________________________________________ Maxim Integrated Products
1
Ordering Information
DIGIT 1
R1
R6
R7
C1
R4
R3
R2
R5
C2
C3
C5
C4
DIGIT 0
O0
O1
O2
O3
O4
O5
O6
O14
O15
O16
O17
O18
R1
R6
R7
C1
R4
R3
R2
R5
C2
C3
C5
C4
O0
O1
O2
O3
O4
O5
O6
O19
O20
O21
O22
O23
R1
R6
R7
C1
R4
R3
R2
R5
C2
C3
C5
C4
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
R1
R6
R7
C1
R4
R3
R2
R5
C2
C3
C5
C4
DIGIT 3
O7
O8
O9
O10
O11
O12
O13
O19
O20
O21
O22
O23
DIGIT 2
3.3V
100nF
47
µF
O0
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
ISET
OSC
V+
V+
GND
GND
BLINK
V+
GND
SDA
SCL
AD1
26pF
C
SET
53.6k
R
SET
MAX6953
AD0
3.3V
4.7k
4.7k
4.7k
Typical Application Circuit
19-2312; Rev 2; 11/02
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.
PART
TEMP RANGE
PIN-PACKAGE
MAX6953EAX
-40°C to +85°C
36 SSOP
MAX6953EPL
-40°C to +85°C
40 PDIP
I
2
C is a trademark of Philips Corp.
SPI is a trademark of Motorola, Inc.
Pin Configurations appear at end of data sheet.
MAX6953
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
7
Matrix LED Display Driver
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
DC ELECTRICAL CHARACTERISTICS
(Typical operating circuit, V+ = 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
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 (with Respect to GND)
V+ .............................................................................-0.3V to +6V
All Other Pins................................................-0.3V to (V+ + 0.3V)
O0O13 Sink Current ....................................................... 500mA
O14O23 Source Current .................................................. 50mA
Continuous Power Dissipation (T
A
= +70°C)
36-Pin SSOP (derate 11.8mW/°C above +70°C) .....941.2mW
40-Pin PDIP (derate 16.7mW/°C above +70°C)........1333mW
Operating Temperature Range
MAX6953E ......................................................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Operating Supply Voltage
V+
2.7
5.5
V
T
A
= T
MIN
to T
MAX
130
Shutdown Supply Current
I
SHDN
Shutdown mode, all
digital inputs at V+
or GND
T
A
= +25°C
70
100
µA
Operating Supply Current
I+
All segments on, intensity set to full,
internal oscillator, no display load
connected, BLINK open circuit
12
15
mA
Master Clock Frequency
(OSC Internal Oscillator)
f
OSC
OSC = RC oscillator, R
SET
= 53.6k
,
C
SET
= 26pF
4
MHz
Master Clock Frequency
(OSC External Clock)
f
OSC
OSC overdriven externally
1
8
MHz
Dead Clock Protection
Frequency
f
OSC
90
kHz
OSC Internal/External Detection
Threshold
V
OSC
1.7
V
OSC High Time
t
CH
50
ns
OSC Low Time
t
CL
50
ns
Slow Segment Blink Period
(OSC Internal Oscillator)
f
SLOWBLINK
OSC = RC oscillator, R
SET
= 53.6k
,
C
SET
= 26pF
1
s
Fast Segment Blink Period
(OSC Internal Oscillator)
f
FASTBLINK
OSC = RC oscillator, R
SET
= 53.6k
,
C
SET
= 26pF
0.5
s
Fast or Slow Segment Blink
Duty Cycle (Note 2)
49.5
50.5
%
Column Drive Source Current
I
COLUMN
V
LED
= 2.4V, V+ = 3.0V, T
A
= +25
o
C
-32
-48
mA
MAX6953
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
7
Matrix LED Display Driver
_______________________________________________________________________________________
3
DC ELECTRICAL CHARACTERISTICS (continued)
(Typical operating circuit, V+ = 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Segment Current Slew Rate
I
SEG
/
t
T
A
= +25
o
C
12.5
mA/µs
Segment Drive Current
Matching (Within IC)
I
SEG
T
A
= +25°C
4
%
LOGIC INPUTS
Input High Voltage
SDA, SCL, AD0, AD1
V
IH
0.7 x
V+
V
Input Low Voltage
SDA, SCL, AD0, AD1
V
IL
0.3
V+
V
Input Hysteresis
SDA, SCL, AD0, AD1
V
HYST
0.05
V+
V
Input Leakage Current
I
IL
, I
IH
-2
2
µA
Input Capacitance
C
I
10
pF
DIGITAL OUTPUT
SDA Output Low Voltage
V
OLSDA
I
SINK
= 4mA
0.4
V
BLINK Output Low Voltage
V
OLBK
I
SINK
= 1.6mA
0.4
V
MAX6953 TIMING CHARACTERISTICS
(V+ = 2.7V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Serial Clock Frequency
f
SCL
400
kHz
Bus Free Time Between a STOP
and a START Condition
t
BUF
1.3
µs
Hold Time (Repeated) START
Condition
t
HD
,
STA
0.6
µs
Repeated START Condition
Setup Time
t
SU
,
STA
0.6
µs
STOP Condition Setup Time
t
SU, STO
0.6
µs
Data Hold Time
t
HD, DAT
(Note 3)
0.9
µs
Data Setup Time
t
SU, DAT
100
ns
SCL Clock Low Period
t
LOW
1.3
µs
SCL Clock High Period
t
HIGH
0.6
µs
Rise Time of Both SDA and SCL
Signals, Receiving
t
R
(Notes 2, 4)
20 +
0.1C
B
300
ns
Fall Time of Both SDA and SCL
Signals, Receiving
t
F
(Notes 2, 4)
20 +
0.1C
B
300
ns
Typical Operating Characteristics
(Typical application circuit, V+ = 3.3V, LED forward voltage = 2.4V, scan limit set to 4 digits, T
A
= +25°C, unless otherwise noted.)
MAX6953
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
7
Matrix LED Display Driver
4
_______________________________________________________________________________________
MAX6953 TIMING CHARACTERISTICS (continued)
(V+ = 2.7V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Fall Time of SDA Transmitting
t
F
(Notes 2, 5)
20 +
0.1C
B
250
ns
Pulse Width of Spike Suppressed
t
SP
(Note 6)
0
50
ns
Capacitive Load for Each
Bus Line
C
B
(Note 2)
400
pF
Note 1: All parameters tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Guaranteed by design.
Note 3: A master device must provide a hold time of at least 300ns for the SDA signal (referred to V
IL
of the SCL signal) in order to
bridge the undefined region of SCL's falling edge.
Note 4: C
B
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.3V+ and 0.7V+.
Note 5: I
SINK
6mA. C
B
= total capacitance of one bus line in pF. t
R
and t
F
measured between 0.3V+ and 0.7V+.
Note 6: Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns.
3.80
3.90
4.10
4.00
4.20
4.30
-40
0
-20
20
40
60
80
INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
MAX6953 toc01
TEMPERATURE (
°C)
OSCILLATOR FREQUENCY (MHz)
V+ = 3.3V
V+ = 2.7V
V+ = 5V
INTERNAL OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6953 toc02
SUPPLY VOLTAGE (V)
OSCILLATOR FREQUENCY (MHz)
4.5
3.5
3.7
3.8
3.9
4.0
4.1
4.2
4.3
4.4
3.6
2.5
5.5
0
0.5
1.5
1.0
2.0
2.5
0
400
200
600
800
INTERNAL OSCILLATOR
WAVEFORM AT OSC (PIN 19 OR 21)
MAX6953 toc03
TIMELINE (ns)
VOLTAGE AT OSC (V)
MAX6953
2-Wire Interfaced, 2.7V to 5.5V, 4-Digit 5
7
Matrix LED Display Driver
_______________________________________________________________________________________
5
80
85
95
90
100
105
2.5
3.5
3.0
4.0
4.5
5.0
5.5
DEAD CLOCK OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6953 toc04
SUPPLY VOLTAGE (V)
OSCILLATOR FREQUENCY (kHz)
0.95
0.97
0.96
0.99
0.98
1.00
1.01
2.5
3.5
4.0
3.0
4.5
5.0
5.5
OUTPUT SOURCE CURRENT
vs. SUPPLY VOLTAGE
MAX6953 toc05
SUPPLY VOLTAGE (V)
CURRENT NORMALIZED TO 40mA
WAVEFORMS AT O2 (PIN 3) AND O14
(PIN 28) V+ = 3.3V, 8/16 INTENSITY
GROUND FOR
ANODE
(PIN 014)
MAX6953 toc06
GROUND FOR
CATHODE
(PIN 03)
200
µs/div
Typical Operating Characteristics (continued)
(Typical application circuit, V+ = 3.3V, LED forward voltage = 2.4V, scan limit set to 4 digits, T
A
= +25°C, unless otherwise noted.)
Pin Description
PIN
SSOP
PDIP
NAME
FUNCTION
1, 2, 3, 614, 23, 24
1, 2, 3, 715, 26, 27
O0 to O13
LED Cathode Drivers. O0 to O13 outputs sink current from
the display's cathode rows.
4, 5, 17
4, 5, 6, 19
GND
Ground
15
17
ISET
Segment Current Setting. Connect ISET to GND through
series resistor R
SET
to set the peak current.
16
18
AD1
Address Input 1. Sets device slave address. Connect to
either GND, V+, SCL, SDA to give four logic combinations.
See Table 3.
--
16, 25
N.C.
Not Connected
18
20
BLINK
Blink Output. Output is open drain.
19
21
OSC
Multiplex Clock Input. To use internal oscillator, connect
capacitor C
SET
from OSC to GND. To use external clock,
drive OSC with a 1MHz to 8MHz CMOS clock.
20
22
AD0
Address Input 0. Sets device slave address. Connect to
either GND, V+, SCL, SDA to give four logic combinations.
See Table 3.
21
23
SDA
I
2
C-Compatible Serial Data I/O
22
24
SCL
I
2
C-Compatible Serial Clock Input
2531, 34, 35, 36
2834, 38, 39, 40
O14 to O23
LED Anode Drivers. O14 to O23 outputs source current to
the display's anode columns.
32, 33
35, 36, 37
V+
Positive Supply Voltage. Bypass V+ to GND with a 47µF
bulk capacitor and a 0.1µF ceramic capacitor.
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