Rainbow Electronics MAX1845 - Manual (Page 4)

MAX1845
Dual, High-Efficiency, Step-Down
Controller with Accurate Current Limit
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V DD = V CC = 5V, SKIP = GND, V+ = 15V, T A = 0°C to +85°C, typical values are at +25°C, unless otherwise
noted.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
GND - V CS , V ILIM _ = 0.5V 40 50 60 Current-Limit Threshold
(Adjustable)
GND - V CS , V ILIM _ = 1V 85 100 115
mV
ILIM_ Adjustment Range V ILIM _ 0.3 2.5 V
Negative Current-Limit Threshold
(Fixed)
CS_ = GND, ILIM_ = V CC , T A = +25 o C -75 -60 -45 mV
Thermal Shutdown Threshold Hysteresis = 15 o C 160 o C
V CC Undervoltage Lockout
Threshold
Rising edge, hysteresis = 20mV, PWMs
disabled below this level
4.05 4.4 V
DH_ Gate Driver On-Resistance V BST _ = V LX _ = 5V 1.5 5 Ω
DL_ Gate Driver On-Resistance
(Pullup)
DL_, high state 1.5 5 Ω
DL_ Gate Driver On-Resistance
(Pulldown)
DL_, low state 0.5 1.7 Ω
DH_ Gate Driver Source/Sink
Current
V DH _ = 2.5V, V BST _ = V LX _ = 5V 1 A
DL_ Gate Driver Sink Current V DL _ = 2.5V 3 A
DL_ Gate Driver Source Current V DL _ = 2.5V 1 A
ON_, SKIP 2.4
Logic Input High Voltage V IH
UVP
V CC -
0.4
V
ON_, SKIP 0.8
Logic Input Low Voltage V IL
UVP 0.05
V
TON Threshold TON
V CC -
0.4
V
Float level 3.15 3.85
REF level 1.65 2.35 TON
GND level 0.5
V
Logic Input Current TON (GND or V CC ) -3 3 µA
Logic Input Current ON_, SKIP, UVP -1 1 µA
PGOOD Trip Threshold (Lower)
With respect to error-comparator trip
threshold, falling edge
-12.5 -10 -7.5 %
PGOOD Trip Threshold (Upper)
With respect to error-comparator trip
threshold, rising edge
+7.5 +10 +12.5 %
PGOOD Propagation Delay
Falling edge, FB_ forced 2% below PGOOD
trip threshold
1.5 µs
PGOOD Output Low Voltage I SINK = 1mA 0.4 V
PGOOD Leakage Current High state, forced to 5.5V 1 µA