19-2437; Rev 1; 10/02
KIT
ATION
EVALU
BLE
AVAILA
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
General Description
Features
o
High-Speed 26MHz with SPI-/QSPI-™/
MICROWIRE™-Compatible Serial Interface
o
2.7V to 5.5V Operation
o
Drives Four Monocolor or Two 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
36µA 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
MAX6952
The MAX6952 is a compact cathode-row display driver
that interfaces microprocessors to 5
✕
7 dot-matrix LED
displays through an SPI™-compatible serial interface.
The MAX6952 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 a 2-wire interfaced version, refer to the MAX6953
data sheet. An EV kit is available for the MAX6952.
Applications
Message Boards
Medical Equipment
Industrial Displays
Audio/Video
Equipment
Gaming Machines
PART
MAX6952EAX
MAX6952EPL
Ordering Information
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
36 SSOP
40 PDIP
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
Pin Configurations appear at end of data sheet.
Typical Application Circuit
DIGIT 0
DIGIT 1
O19
O20
O21
O22
O23
O0
O1
O2
O3
O4
O5
O6
C1
C2
C3
C4
C5
3.3V
V+
V+
100nF
47µF
GND
GND
GND
3.3V
MAX6952
4.7kΩ
CLK
DIN
CS
DOUT
BLINK
OSC
ISET
C
SET
26pF
R
SET
53.6kΩ
O0
O1
O2
O3
O4
O5
O6
O7
O8
O9
O10
O11
O12
O13
O14
O15
O16
O17
O18
O19
O20
O21
O22
O23
O14
O15
O16
O17
O18
O0
O1
O2
O3
O4
O5
O6
C1
C2
C3
C4
C5
R1
R2
R3
R4
R5
R6
R7
R1
R2
R3
R4
R5
R6
R7
DIGIT 2
O14
O15
O16
O17
O18
O7
O8
O9
O10
O11
O12
O13
C1
C2
C3
C4
C5
O19
O20
O21
O22
O23
O7
O8
O9
O10
O11
O12
O13
DIGIT 3
C1
C2
C3
C4
C5
R1
R2
R3
R4
R5
R6
R7
R1
R2
R3
R4
R5
R6
R7
________________________________________________________________
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.
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
MAX6952
ABSOLUTE MAXIMUM RATINGS
Voltage (with respect to GND)
V+ .............................................................................-0.3V to +6V
All Other Pins................................................-0.3V to (V+ + 0.3V)
O0–O13 Sink Current ....................................................... 500mA
O14–O23 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 (T
MIN
, T
MAX
) ......-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°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.
DC ELECTRICAL CHARACTERISTICS
(Typical operating circuit, V+ = 3.0V to 5.5V, T
A
= T
MIN
to T
MAX
, unless otherwise noted.) (Note 1)
PARAMETER
Operating Supply Voltage
Shutdown Supply Current
SYMBOL
V+
I
SHDN
Shutdown mode, all
digital inputs at V+ or
GND
T
A
= T
MIN
to T
MAX
T
A
= +25°C
36
CONDITIONS
MIN
2.7
TYP
MAX
5.5
100
80
UNITS
V
µA
Operating Supply Current
Master Clock Frequency (OSC
Internal Oscillator)
Master Clock Frequency (OSC
External Oscillator)
Dead Clock Protection
Frequency
OSC Internal/External Detection
Threshold
OSC High Time
OSC Low Time
Slow Segment Blink Period
(OSC Internal Oscillator)
Fast Segment Blink Period
(OSC Internal Oscillator)
Fast or Slow Segment Duty
Cycle
Column Drive Source Current
Segment Current Slew Rate
Segment Drive Current
Matching (Within IC)
I+
All segments on, intensity set to full,
internal oscillator, DOUT open circuit, no
display load connected, blink open circuit
OSC = RC oscillator, R
SET
= 53.6kΩ,
C
SET
= 26pF
OSC overdriven externally
1
12
16
mA
f
OSC
f
OSC
f
OSC
V
OSC
t
CH
t
CL
f
SLOWBLINK
f
FASTBLINK
4
8
90
1.7
50
50
MHz
MHz
kHz
V
ns
ns
OSC = RC oscillator, R
SET
= 53.6kΩ,
C
SET
= 26pF
OSC = RC oscillator, R
SET
= 53.6kΩ,
C
SET
= 26pF
(Note 2)
49.5
-32
1
0.5
50.5
-48
12.5
4
s
s
%
mA
mA/µs
%
I
COLUMN
∆I
SEG
/∆t
∆I
SEG
V
LED
= 2.4V, V+ = 3.0V, T
A
= +25°C
T
A
= +25 C
T
A
= +25
o
C
o
2
_______________________________________________________________________________________
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
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
LOGIC INPUTS AND OUTPUTS
Input High Voltage
DIN, CLK,
CS
Input Low Voltage
DIN, CLK,
CS
Input Leakage
DIN, CLK,
CS,
OSC
DOUT Output Low Voltage
DOUT Output High Voltage
Blink Output Low Voltage
CLK Clock Period
CLK Pulse Width High
CLK Pulse Width Low
CS
Fall to CLK Rise Setup Time
CLK Rise to
CS
Rise Hold Time
DIN Setup Time
DIN Hold Time
CS
Pulse High
DOUT Propagation Delay
V
IH
V
IL
I
IH
, I
IL
V
OLDO
V
OHDO
V
OLBK
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
DS
t
DH
t
CSW
t
DO
C
LOAD
= 10pF
I
SINK
= 1.6mA
I
SOURCE
= 1.6mA
I
SINK
= 1.6mA
38.4
19
19
9.5
5
9.5
0
19
19
V+
- 0.4V
0.4
-2
+0.1
2.4
0.4
+2
0.4
V
V
µA
V
V
V
ns
ns
ns
ns
ns
ns
ns
ns
ns
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX6952
TIMING CHARACTERISTICS
(Figure 1)
Note 1:
All parameters tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2:
Guaranteed by design.
_______________________________________________________________________________________
3
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
MAX6952
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.)
INTERNAL OSCILLATOR
FREQUENCY vs. TEMPERATURE
MAX6952 toc01
INTERNAL OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6952 toc02
INTERNAL OSCILLATOR
WAVEFORM AT OSC
MAX6952 toc03
4.30
OSCILLATOR FREQUENCY (MHz)
4.4
OSCILLATOR FREQUENCY (MHz)
4.3
4.2
4.1
4.0
3.9
3.8
2.5
4.20
V+ = 2.7V
2.0
VOLTAGE AT OSC (V)
4.10
V+ = 3.3V
4.00
V+ = 5V
3.90
1.5
1.0
0.5
3.7
3.80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
3.6
2.5
3.5
4.5
5.5
SUPPLY VOLTAGE (V)
0
0
200
400
TIMELINE (ns)
600
800
DEAD CLOCK OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6952 toc04
SEGMENT SOURCE CURRENT
vs. SUPPLY VOLTAGE
MAX6952 toc05
105
OSCILLATOR FREQUENCY (kHz)
1.01
CURRENT NORMALIZED TO 40mA
1.00
0.99
0.98
0.97
0.96
0.95
100
95
90
85
80
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
2.5
3.0
3.5
4.0
4.5
5.0
5.5
SUPPLY VOLTAGE (V)
WAVEFORMS AT O2 (PIN 3) AND O14
(PIN 28) 15/16 INTENSITY
MAX6952 toc06
GROUND FOR
ANODE
(PIN O14)
GROUND FOR
CATHODE
(PIN O3)
220
m
s/div
4
_______________________________________________________________________________________
4-Wire Interfaced, 2.7V to 5.5V,
4-Digit 5
✕
7 Matrix LED Display Driver
Pin Description
PIN
SSOP
1, 2, 3, 6–14, 23, 24
4, 5, 16
15
17
18
PDIP
1, 2, 3, 7–15, 26, 27
4, 5, 6, 18
17
19
20
NAME
O0 to O13
GND
ISET
BLINK
DIN
FUNCTION
LED Cathode Drivers. O0 to O13 outputs sink current from
the display’s cathode rows.
Ground
Segment Current Setting. Connect ISET to GND through
series resistor R
SET
to set the peak current.
Blink Clock Output. Output is open drain.
Serial Data Input. Data is loaded into the internal 16-bit shift
register on the rising edge of the CLK.
Serial-Clock Input. On the rising edge of CLK, data is
shifted into the internal shift register. On the falling edge of
CLK, data is clocked out of DOUT. CLK input is active only
while
CS
is low.
Serial Data Output. Data clocked into DIN is output to
DOUT 15.5 clock cycles later. Data is clocked out on the
rising edge of CLK. Output is push-pull.
Chip-Select Input. Serial data is loaded into the shift register
while
CS
is low. The last 16 bits of serial data are latched on
CS’s
rising edge.
Multiplex Clock Input. To use the internal oscillator, connect
capacitor C
SET
from OSC to GND. To use the external
clock, drive OSC with a 1MHz to 8MHz CMOS clock.
LED Anode Drivers. O14 to O23 outputs source current to
the display’s anode columns.
Positive Supply Voltage. Bypass V+ to GND with a 47µF
bulk capacitor and a 0.1µF ceramic capacitor.
MAX6952
19
21
CLK
20
22
DOUT
21
23
CS
22
24
OSC
25–31, 34, 35, 36
32, 33
28–34, 38, 39, 40
35, 36, 37
O14 to O23
V+
Detailed Description
The MAX6952 is a serially interfaced display driver that
can drive four digits of 5
✕
7 cathode-row dot-matrix
displays. The MAX6952 can drive either four monocolor
digits (Table 1) or two bicolor digits (Table 2). The
MAX6952 includes a 128-character font map compris-
ing 104 predefined characters and 24 user-definable
characters. The predefined characters follow the Arial
font, with the addition of the following common sym-
bols: £,
€,
¥, °, µ, ±,
↑,
and
↓.
The 24 user-definable
characters are uploaded by the user into on-chip RAM
through the serial interface and are lost when the
device is powered down. Figure 1 is the MAX6952
functional diagram.
Serial Interface
The MAX6952 communicates through an SPI-compati-
ble 4-wire serial interface. The interface has three
inputs, clock (CLK), chip select (CS), and data in (DIN),
and one output, data out (DOUT).
CS
must be low to
clock data into or out of the device, and DIN must be
stable when sampled on the rising edge of CLK. DOUT
is stable on the rising edge of CLK. Note that while the
SPI protocol expects DOUT to be high impedance
when the MAX6952 is not being accessed, DOUT on
the MAX6952 is never high impedance.
_______________________________________________________________________________________
5