Datasheet

(V+ = 3.3V, LED forward voltage = 2.4V, typical application circuit, T
A
= +25°C, unless otherwise noted.)
PORT INPUT PULLUP CURRENT
vs. TEMPERATURE
MAX6954 toc08
TEMPERATURE (°C)
KEY-SCAN SOURCE CURRENT (mA)
11050 8020-10
0.05
0.10
0.15
0.20
0.25
0.30
0
-40
V
CC
= 3.3V
V
CC
= 2.5V
V
CC
= 5.5V
OUTPUT = HIGH
V
PORT
= 1.4V
GPIO SINK CURRENT
vs. TEMPERATURE
MAX6954 toc07
TEMPERATURE (°C)
GPIO SINK CURRENT (mA)
11050 8020-10
5
10
15
20
25
30
35
40
45
0
-40
V
CC
= 3.3V
V
CC
= 2.5V
V
CC
= 5.5V
OUTPUT = LOW
V
PORT
= 0.6V
400µs/div
KEY_A: 1V/div
IRQ: 2V/div
MAX6954 toc09
KEY_A
0V
0V
IRQ
KEYSCAN OPERATION
(KEY_A AND IRQ)
1V/div
200µs/div
MAX6954 toc06
O0
O18
WAVEFORM AT PINS O0 AND O18,
MAXIMUM INTENSITY
0V
0V
SEGMENT SOURCE CURRENT
vs. SUPPLY VOLTAGE
MAX6954 toc05
SUPPLY VOLTAGE (V)
CURRENT NORMALIZED TO 40mA
5.04.54.03.53.0
0.94
0.98
1.00
1.02
0.92
2.5 5.5
V
LED
= 1.8V
0.96
DEAD CLOCK OSCILLATOR FREQUENCY
vs. SUPPLY VOLTAGE
MAX6954 toc04
SUPPLY VOLTAGE (V)
OSCILLATOR FREQUENCY (kHz)
5.04.54.03.53.0
85
95
105
110
80
2.5 5.5
R
SET
= 56kΩ
OSC = GND
100
90
Maxim Integrated │ 5
www.maximintegrated.com
MAX6954 4-Wire Interfaced, 2.7V to 5.5V LED Display
Driver with I/O Expander and Key Scan
Typical Operating Characteristics (continued)