Datasheet
MAX1533A/MAX1537A
High-Efficiency, 5x Output, Main Power-Supply
Controllers for Notebook Computers
4 _______________________________________________________________________________________
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
LDO3 Output Voltage V
LDO3
Standby mode, 6V < V
IN
< 26V,
0 < I
LOAD
< 100mA
3.20 3.35 3.42
V
LDO3 Bootstrap Switch Threshold
Rising edge of CSL3, hysteresis = 1%
2.83 3.10
V
LDO3 Bootstrap Switch
Resistance
LDO3 to CSL3, V
CSL3
= 3.2V,
I
LDO3
= 50mA
13Ω
Short-Circuit Current
LDO3 = LDO5 = GND,
CSL3 = CSL5 = GND
150
220 mA
Short-Circuit Current (Switched
Over to CSL_)
LDO3 = LDO5 = GND, V
CSL3
> 3.1V,
V
CSL5
> 4.7V
250
mA
AUXILIARY LINEAR REGULATOR (MAX1537A ONLY)
LDOA Voltage Range V
LDOA
523V
INA Voltage Range V
INA
624V
LDOA Regulation Threshold,
Internal Feedback
ADJA = GND, 0 < I
LDOA
< 120mA,
V
INA
> 13V
11.4 12.0 12.4
V
ADJA Regulation Threshold,
External Feedback
V
ADJA
0 < I
LDOA
< 120mA, V
LDOA
> 5.0V and
V
INA
> V
LDOA
+ 1V
1.94 2.00 2.06
V
ADJA Dual-Mode Threshold 0.1
0.15
0.2 V
ADJA Leakage Current V
ADJA
= 2.1V
-0.1 +0.1
µA
LDOA Current Limit
V
LDOA
forced to V
INA
- 1V, V
ADJA
= 1.9V,
V
INA
> 6V
150
mA
Secondary Feedback Regulation
Threshold
V
INA
- V
LDOA
0.65
0.8
0.95
V
DL Duty Factor
V
INA
- V
LDOA
< 0.7V, pulse width with
respect to switching period
33 %
INA Quiescent Current I
INA
V
INA
= 24V, I
LDOA
= no load 50 165 µA
INA Shunt Sink Current V
INA
= 28V 10 mA
INA Leakage Current
I
INA
(
SHDN
)
V
INA
= 5V, LDOA disabled 30 µA
REFERENCE (REF)
Reference Voltage V
REF
V
CC
= 4.5V to 5.5V, I
REF
= 0
1.985 2.00 2.015
V
Reference Load Regulation I
REF
= -10µA to +100µA
1.980 2.020
V
REF Lockout Voltage
V
REF
(
UVLO
)
Rising edge, hysteresis = 350mV
1.95
V
FAULT DETECTION
Output Overvoltage Trip
Threshold
OVP = GND, with respect to error-
comparator threshold
81115%
Output Overvoltage Fault-
Propagation Delay
t
OVP
50mV overdrive 10 µs