User Manual

MAX1540/MAX1541
Dual Step-Down Controllers with Saturation
Protection, Dynamic Output, and Linear Regulator
_______________________________________________________________________________________ 3
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
Standby Supply Current
(V
DD
, MAX1541 Only)
ON1 = ON2 = GND, V
LDOON
= V+ = 28V <1 5 µA
MAX1540: ON1 = ON2 = GND,
LDOON = V+ = 28V, V
CC
= 0 or 5V
105
Standby Supply Current (V+)
MAX1541: ON1 = ON2 = GND,
LDOON = V+ = 28V, V
CC
= V
DD
= 0 or 5V
<1 5
µA
Standby Supply Current
(LDOIN, MAX1541 Only)
ON1 = ON2 = GND, V
LDOON
= V+ = 28V 100 µA
Shutdown Supply Current (V
CC
) ON1 = ON2 = LDOON = GND <1 5 µA
Shutdown Supply Current
(V
DD
, MAX1541 Only)
ON1 = ON2 = LDOON = GND <1 5 µA
MAX1540: ON1 = ON2 = LDOON = GND,
V+ = 28V, V
CC
= 0 or 5V
415
Shutdown Supply Current (V+)
MAX1541: ON1 = ON2 = LDOON = GND,
V+ = 28V, V
CC
= V
DD
= 0 or 5V
<1 5
µA
Shutdown Supply Current
(LDOIN, MAX1541 Only)
LDOON = GND 4 10 µA
PWM CONTROLLERS
FB1 = GND 1.782 1.80 1.818
V
OUT1
Preset output,
V+ = 5.5V to 28V,
SKIP = V
CC
FB1 = V
CC
1.188 1.20 1.212
MAX1540 Main Output-Voltage
Accuracy (OUT1) (Note 2)
V
FB1
Adjustable output, V+ = 5.5V to 28V,
SKIP = V
CC
0.693 0.70 0.707
V
FB2 = GND 2.475 2.50 2.525
V
OUT2
Preset output,
V+ = 5.5V to 28V,
SKIP = V
CC
FB2 = V
CC
1.485 1.50 1.515
MAX1540 Secondary Output-
Voltage Accuracy (OUT2)
(Note 2)
V
FB2
Adjustable output, V+ = 5.5V to 28V,
SKIP = V
CC
0.693 0.70 0.707
V
MAX1541 Main Feedback-
Voltage Accuracy (FB1)
V
FB1
V+ = 4.5V to 28V,
SKIP = V
CC
REFIN1 = 0.35 x REF 0.693 0.70 0.707 V
FB2 = GND 2.475 2.50 2.525
V
OUT2
Preset output,
V+ = 4.5V to 28V,
SKIP = V
CC
FB2 = V
CC
1.782 1.80 1.818
MAX1541 Secondary Output-
Voltage Accuracy (OUT2)
(Note 2)
V
FB2
Adjustable output, V+ = 4.5V to 28V,
SKIP = V
CC
0.693 0.70 0.707
V
Load-Regulation Error I
LOAD
= 0 to 3A, SKIP = V
CC
0.1 %
Line-Regulation Error V
CC
= 4.5V to 5.5V, V+ = 4.5V to 28V 0.25 %
FB_ Input Bias Current I
FB
_ -0.1 +0.1 µA
Output Adjust Range 0.7 5.5 V