Rainbow Electronics MAX1845 - Manual (Page 3)

MAX1845
Dual, High-Efficiency, Step-Down
Controller with Accurate Current Limit
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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
TON = GND 160 182 204
TON = REF 205 234 263
TON = float 301 336 371
On-Time, Side 2 (Note 3) t ON2
V+ = 24V,
V
OUT2 = 2V
TON = V CC 432 483 534
ns
TON = GND 125 135 145
TON = REF 125 135 145
TON = float 125 135 145
On-Time Tracking (Note 3)
On-time 2 with
respect to on-
time 1
TON = V CC 125 135 145
%
Minimum Off-Time (Note 3) t OFF 400 500 ns
Quiescent Supply Current (V CC ) I CC FB_ forced above the regulation point 1100 1500 µA
Quiescent Supply Current (V DD ) I DD FB_ forced above the regulation point <1 5 µA
Quiescent Supply Current (V+) I+ Measured at V+ 25 70 µA
ON1 = ON2 = GND, OVP = V CC or GND <1 5
Shutdown Supply Current (V CC )
ON1 = ON2 = GND, V OVP = 1.8V 1 5
µA
Shutdown Supply Current (V DD ) ON1 = ON2 = GND <1 5 µA
Shutdown Supply Current (V+)
ON1 = ON2 = GND, measured at V+,
V
CC = GND or 5V
<1 5 µA
Reference Voltage V REF V CC = 4.5V to 5.5V, no external REF load 1.98 2 2.02 V
Reference Load Regulation I REF = 0 to 50µA 0.01 V
REF Sink Current REF in regulation 10 µA
REF Fault Lockout Voltage Falling edge, hysteresis = 40mV 1.6 V
Overvoltage Trip Threshold
(Fixed-Threshold Mode) OVP = GND, with respect to error-
comparator trip threshold
112 114 117 %
1V < V OVP < 1.8V, external feedback,
measured at FB_ with respect to V OVP
-28 0 28 mV
Overvoltage Comparator Offset
(Adjustable-Threshold Mode)
1V < V OVP < 1.8V, internal feedback,
measured at OUT_ with respect to OUT_
regulation point -3.5 0 +3.5 %
OVP Input Leakage Current 1V < V OVP < 1.8V -100 <1 100 nA
Overvoltage Fault Propagation
Delay
FB_ forced 2% above trip threshold 1.5 µs
Output Undervoltage Threshold
UVP = V CC , with respect to error-comparator
trip threshold
65 70 75 %
Output Undervoltage Protection
Blanking Time
From ON_ signal going high 10 30 ms
Current-Limit Threshold (Fixed) GND - V CS , ILIM_ = V CC 40 50 60 mV