Datasheet

MAX1533A/MAX1537A
High-Efficiency, 5x Output, Main Power-Supply
Controllers for Notebook Computers
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(Circuit of Figure 1, V
IN
= 12V, both SMPS enabled, V
CC
= 5V, FSEL = REF, SKIP = GND, V
ILIM_
= V
LDO5
, V
INA
= 15V, V
LDOA
= 12V,
I
LDO5
= I
LDO3
= I
LDOA
= no load, 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
Line-Regulation Error Either SMPS, duty cycle = 10% to 90% 1 %
FSEL = GND
170 200
230
FSEL = REF
270 300
330
Operating Frequency (Note 1) f
OSC
FSEL = V
CC
425 500
575
kHz
FSEL = GND 91 93
FSEL = REF 91 93Maximum Duty Factor (Note 1) D
MAX
FSEL = V
CC
91 93
%
Minimum On-Time
t
ON
(
MIN
)
(Note 3) 200 ns
40 %
SMPS3 to SMPS5 Phase Shift SMPS5 starts after SMPS3
144
Deg
CURRENT LIMIT
ILIM_ Adjustment Range 0.5
V
REF
V
Current-Sense Input Range CSH_, CSL_ 0 5.5 V
Current-Sense Input Leakage
Current
CSH_, V
CSH
_ = 5.5V -1 +1 µA
Current-Limit Threshold (Fixed) V
LIMIT
_V
CSH
_ - V
CSL
_ , ILIM_ = V
CC
70 75 80 mV
V
ILIM
_ = 2.00V
170 200
230
V
ILIM
_ = 1.00V 91
100
109
Current-Limit Threshold
(Adjustable)
V
LIMIT
_
V
CSH
_ - V
CSL
_
V
ILIM
_ = 0.50V 42 50 58
mV
Current-Limit Threshold
(Negative)
V
NEG
V
CSH_
- V
CSL_
, SKIP = V
CC
, percent of
current limit
-120
%
Current-Limit Threshold (Zero
Crossing)
V
ZX
V
PGND
- V
LX
_, SKIP = GND, ILIM_ = V
CC
3mV
ILIM_ = V
CC
10 16 22 mV
Idle Mode™ Threshold V
IDLE
V
CSH
_ - V
CSL
_
With respect to current-
limit threshold (V
LIMIT
)
20 %
ILIM_ Leakage Current ILIM3 = ILIM5 = GND or V
CC
-0.1 +0.1
µA
Soft-Start Ramp Time t
SS
Measured from the rising edge of ON_ to
full scale
512/
f
OSC
s
INTERNAL FIXED LINEAR REGULATORS
LDO5 Output Voltage V
LDO5
ON3 = ON5 = GND, 6V < V
IN
< 26V,
0 < I
LDO5
< 100mA
4.80 4.95 5.10
V
LDO5 Undervoltage-Lockout Fault
Threshold
Rising edge, hysteresis = 1%
3.75
4.0
4.25
V
LDO5 Bootstrap Switch Threshold
Rising edge of CSL5, hysteresis = 1%
4.41 4.75
V
LDO5 Bootstrap Switch
Resistance
LDO5 to CSL5, V
CSL5
= 5V,
I
LDO5
= 50mA
0.75
3 Ω
Idle Mode is a trademark of Maxim Integrated Products, Inc.