User Manual

MAX1540/MAX1541
Dual Step-Down Controllers with Saturation
Protection, Dynamic Output, and Linear Regulator
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, V
CC
= V
DD
= ON1 = ON2 = 5V, SKIP = GND, T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
REFERENCE (REF)
T
A
= + 25° C to + 85° C 1.986 2.00 2.014
Reference Voltage V
REF
V
CC
= 4.5V to 5.5V,
I
REF
= 0V
T
A
= 0° C to +85°C 1.983 2.00 2.017
V
Reference Load Regulation ∆V
REF
I
REF
= -10µA to +50µA -0.01 +0.01 V
REF Lockout Voltage V
REF
(
UVLO
)
Rising edge, hysteresis = 350mV 1.95 V
REFIN1 (MAX1541)
Voltage Range
V
REFIN
0.7 V
REF
V
REFIN1 (MAX1541)
Input Bias Current
I
REFIN1
0.01 0.05 µA
FAULT DETECTION
Overvoltage Trip Threshold
With respect to error-comparator threshold,
OVP/UVP = V
CC
12 16 20 %
Overvoltage Fault-Propagation
Delay
t
OVP
FB forced 2% above trip threshold 10 µs
Output Undervoltage-Protection
Trip Threshold
With respect to error-comparator threshold,
OVP/UVP = V
CC
65 70 75 %
Output Undervoltage-Protection
Blanking Time
t
BLANK
From rising edge of ON_ 10 35 ms
Output Undervoltage Fault-
Propagation Delay
t
UVP
10 µs
PGOOD_ Lower Trip Threshold
With respect to error-comparator threshold,
hysteresis = 1%
-13 -10 -7 %
PGOOD_ Upper Trip Threshold
With respect to error-comparator threshold,
hysteresis = 1%
+7 +10 +13 %
PGOOD_ Propagation Delay t
PGOOD
_
FB forced 2% beyond P GOOD _ trip threshold
10 µs
PGOOD_ Output Low Voltage I
SINK
= 4mA 0.3 V
PGOOD_ Leakage Current I
PGOOD
_
FB = REF (PGOOD high impedance),
PGOOD forced to 5.5V
1µA
FBLANK = V
CC
120 220 320
FBLANK = open 80 140 205
Fault-Blanking Time
(MAX1541 Only)
t
FBLANK
FBLANK = REF 35 65 95
µs
LDOON = V
CC
+150
Thermal-Shutdown Threshold T
SHDN
Hysteresis = 10°C
LDOON = GND +160
°C
V
CC
Undervoltage-Lockout
Threshold
V
UVLO
(
VCC
)
Rising edge, PWM disabled below this
level, hysteresis = 20mV
4.1 4.25 4.4 V
CURRENT LIMIT
ILIM_ Adjustment Range 0.25 2 V
CSP_ 0 2.7
Current-Limit Input Range
CSN_ -0.3 +28
V
CSP_/CSN_ Input Current 0.5 µA