Rainbow Electronics MAX1855 - Manual (Page 5)

MAX1716/MAX1854/MAX1855
High-Speed, Adjustable, Synchronous Step-Down
Controllers with Integrated Voltage Positioning
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ELECTRICAL CHARACTERISTICS
(Circuit of Figure 1, V+ = +15V, V CC = V DD = 5V, SKIP = V CC , VPS = PGND, T A = -40°C to +85°C, unless otherwise noted.) (Note 6)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
PWM CONTROLLER
Battery voltage, V+ 2 28
Input Voltage Range
V CC , V DD 4.5 5.5
V
DAC codes from
1.35V to 2.0V
-1.6 1.6
DC Output Voltage Accuracy
(Notes 2, 3) V+ = 4.5V to 28V,
VPS = PGND
DAC codes from
0.6V to 1.3V
-2 2
%
FB Input Bias Current I
FB
FB = 0.6V to 2.0V -0.2 0.2 µA
VPS Input Bias Current I VPS V VPS = ±40mV -1 1 µA
VPS Gain A VPS V VPS = 0 or -40mV, gain from VPS to FB 0.153 0.197 %/mV
CS Input Bias Current I CS 0 to 28V -1 1 µA
ILIM Input Leakage Current I ILIM V ILIM = 0 or 5.0V 100 nA
TON = GND 205 300
TON = REF 280 375
TON = open 425 520
On-Time (Note 4) t ON
V+ = 11.0V,
V
FB = 1.5V
TON = V CC 615 740
ns
Minimum Off-Time (Note 4) t OFF( M IN) 500 ns
BIAS AND REFERENCE
Quiescent Supply Current (V CC ) I CC
Measured at V CC , FB forced above the
regulation point
950 µA
Quiescent Supply Current (V DD ) I DD
Measured at V DD , FB forced above the
regulation point
5 µA
Quiescent Supply Current (V+) I+ 40 µA
Shutdown Supply Current (V CC ) SHDN = GND 5 µA
Shutdown Supply Current (V DD ) SHDN = GND 5 µA
Shutdown Supply Current (V+) S HDN = GN D , V + = 28V , V
C C = V D D = 0 or 5V 5 µA
Reference Voltage V REF V CC = 4.5V to 5.5V, no external REF load 1.98 2.02 V
Reference Load Regulation I REF = 0 to 50 µA 0.01 V
REF Sink Current I REF REF in regulation 10 µA
FAULT PROTECTION
MAX1716 1.8 2.0 V Output Overvoltage Fault
Threshold (Note 5)
Measured at FB
MAX1855 1.97 2.03
Output Undervoltage Fault
Threshold (Foldback)
35 45 %
Output Undervoltage Fault
Blanking Time (Foldback)
From SHDN signal going high 10 30 ms