Datasheet

MAX1856
Wide Input Range, Synchronizable,
PWM SLIC Power Supply
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ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= SYNC/SHDN, V
CC
= 5V, V
LDO
= 5V, R
OSC
= 200kΩ, T
A
= 0°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Minimum EXT Pulse Width 290 ns
Minimum SYNC Input Signal
Duty Cycle
20 45 %
Minimum SYNC Input
Low Pulse Width
50 200 ns
Maximum SYNC Input
Rise/Fall Time
200 ns
SYNC Input Frequency Range f
SYNC
100 500 kHz
SYNC/SHDN Falling Edge to
Shutdown Delay
t
SHDN
50 µs
SYNC/SHDN Input High Voltage V
IH
2.0 V
SYNC/SHDN Input Low Voltage V
IL
0.45 V
V
SYNC/SHDN
= 5V 0.5 3.0
SYNC/SHDN Input Current
V
SYNC/SHDN
= 28V 1.5 10
µA
EXT Sink/Source Current I
EXT
EXT forced to 2V 1 A
EXT On-Resistance R
ON(EXT)
EXT high or low 2 5 Ω
ELECTRICAL CHARACTERISTICS
(V
CC
= SYNC/SHDN, V
CC
= 5V, V
LDO
= 5V, R
OSC
= 200kΩ, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
PWM CONTROLLER
328V
Operating Input Voltage Range V
CC
V
CC
= V
LDO
2.7 5.5 V
FB Input Current I
FB
V
FB
= -0.05V 50 nA
Current-Limit Threshold V
CS
85 115 mV
CS Input Current I
CS
CS = GND 1 µA
V
CC
Supply Current (Note 1) I
CC
V
FB
= -0.05V, V
CC
= 3V to 28V 400 µA
Shutdown Supply Current SYNC/SHDN = GND, V
CC
= 28V 6 µA
REFERENCE AND LDO REGULATOR
5V ≤ V
CC
≤ 28V 4.50 5.50
LDO Output Voltage V
LDO
R
LDO
= 400Ω
3V ≤ V
CC
≤ 28V 2.65 5.50
V
REF to FB Voltage (Note 2) V
REF
R
REF
= 10kΩ, C
REF
= 0.22µF 1.22 1.28 V
REF Load Regulation I
REF
= 0 to 400µA -10 mV
REF Undervoltage Lockout
Threshold
Rising edge, 1% hysteresis (typ) 1.0 1.2 V
OSCILLATOR
R
OSC
= 100kΩ ±1% 425 575
R
OSC
= 200kΩ ±1% 222 278Oscillator Frequency f
OSC
R
OSC
= 500kΩ ±1% 85 115
kHz