Rainbow Electronics MAX746 - Manual (Page 3)

MAX746
High-Efficiency, PWM, Step-Down,
N-Channel DC-DC Controller
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Note 1: The soft-start fault current is the current sink capability of SS when V REF < 1V or when the device is in shutdown.
Note 2: I SUPP is the supply current drawn by V+, which includes the current drawn by the charge pump. The charge pump
doubles the current drawn by HIGH from the V+ input, so I SUPP = I V+ + 2I HIGH .
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 10V, I LOAD = 0A, I REF = 0 µ A, T A = T MIN to T MAX , unless otherwise noted.)
PARAMETER
SHDN Input Leakage Current
SYMBOL MIN TYP MAX UNITS
LBO Output Voltage Low V OL
nA
0.4 V
LBI Threshold Voltage
1.96 2.00 2.04
V
Compensation Pin Impedance 24 k Ω
EXT Source Current 270 mA
LBI Input Leakage Current nA
LBO Output Leakage Current 1
µ A
SHDN Input Voltage Low V IL 0.4 V
SHDN Input Voltage High V IH 2.0 V
EXT Output Low
EXT Output High V HIGH - 0.1 V
0.25 V
EXT Sink Current 160 mA
MAX746E/M
CONDITIONS
SHDN = 10V
I SINK = 0.5mA
LBI falling
V HIGH = 15V, V EXT = 2.5V
LBI = 2.5V
V+ = 15V, LBO = 15V, LBI = 2.5V
V HIGH forced to 15V, I EXT = -1mA
V HIGH forced to 15V, I EXT = 1mA
V HIGH = 15V, V EXT = 12.5V
MAX746C 1.97 2.00 2.03
100
0.1 100
Charge-Pump Output Voltage
Maximum Duty Cycle 91 96 %
V HIGH V+ + 4 V+ + 5 V+ + 6 V
V LIMIT 125 150 175 mV
V+ = 6V
I HIGH = 0mA to 10mA
V+ – CS
Current-Sense Amplifier
Current-Limit Threshold