1.8V to 28V Input, PWM Step-Up
Controllers in µMAX
MAX668/MAX669
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= V
LDO
= +5V, R
OSC
= 200kΩ, T
A
= -40°C to +85°C, unless otherwise noted.)
PARAMETER
REF Output Voltage
REF Load Regulation
REF Undervoltage Lockout Threshold
OSCILLATOR
R
OSC
= 200kΩ ±1%
Oscillator Frequency
R
OSC
=100kΩ ±1%
R
OSC
= 500kΩ ±1%
R
OSC
= 200kΩ ±1%
Maximum Duty Cycle
Minimum SYNC Input-Pulse Duty Cycle
Minimum SYNC Input Low Pulse Width
SYNC Input Rise/Fall Time
SYNC Input Frequency Range
SYNC/SHDN Input High Voltage
SYNC/SHDN Input Low Voltage
SYNC/SHDN Input Current
EXT On-Resistance
3.0V < V
CC
< 28V
1.8V < V
CC
< 3.0V (MAX669)
3.0V < V
CC
< 28V
1.8V < V
CC
< 3.0V (MAX669)
V
SYNC/SHDN
= 5V
V
SYNC/SHDN
= 28V
EXT high or low
Not tested
100
2.0
1.5
0.45
0.30
3.0
6.5
5
R
OSC
= 100kΩ ±1%
R
OSC
= 500kΩ ±1%
222
425
85
87
86
86
278
575
115
93
94
94
45
200
200
500
%
ns
ns
kHz
V
V
µA
Ω
%
kHz
CONDITIONS
No load, C
REF
= 0.22µF
REF load = 0 to 50µA
Rising edge, 1% hysteresis
1.0
MIN
1.22
MAX
1.28
-10
1.2
UNITS
V
mV
V
Note 1:
This is the V
CC
current consumed when active but not switching. Does not include gate-drive current.
Note 2:
Limits at T
A
= -40°C are guaranteed by design.
4
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
