Datasheet

1.8V to 28V Input, PWM Step-Up
Controllers in µMAX
Typical Operating Characteristics (continued)
(Circuits of Figures 2, 3, 4, and 5; T
A
= +25°C; unless otherwise noted.)
1.240
1.242
1.243
1.241
1.245
1.246
1.244
1.248
1.249
1.247
1.250
-40-200 20406080100
REFERENCE VOLTAGE vs.
TEMPERATURE
MAX668 toc10
TEMPERATURE (°C)
REFERENCE VOLTAGE (V)
V
CC
= 5V
0
100
150
50
250
300
200
400
450
350
500
0 100 200 300 400 500
SWITCHING FREQUENCY vs. R
OSC
MAX668 toc11
R
OSC
(kΩ)
SWITCHING FREQUENCY (kHz)
V
CC
= 5V
0
100
300
400
500
600
-40 0-20 20406080100
SWITCHING FREQUENCY vs.
TEMPERATURE
MAX668 toc12
TEMPERATURE (°C)
SWITCHING FREQUENCY (kHz)
200
100kΩ
165kΩ
499kΩ
V
IN
= 5V
100 1000 10,000
EXT RISE/FALL TIME vs.
CAPACITANCE
MAX668 toc13
CAPACITANCE (pF)
EXT RISE/FALL TIME (ns)
60
0
10
20
30
40
50
t
R
, V
CC
= 3.3V
t
F
, V
CC
= 3.3V
t
R
, V
CC
= 5V
t
F
, V
CC
= 5V
6
Maxim Integrated
MAX668/MAX669