Datasheet

MAX8543/MAX8544
Step-Down Controllers with Prebias Startup,
Lossless Sensing, Synchronization, and OVP
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= 13.2V, V
BST
- V
LX
= 5V, T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
IN, EN, CS+, CS- to GND .......................................-0.3V to +14V
BST, DH to LX ..........................................................-0.3V to +6V
BST to GND ............................................................-0.3V to +20V
DL, COMP, ILIM2, SS, SYNCO,
FSYNC to GND .......................................-0.3V to (V
VL
+ 0.3V)
VL, FB, POK, ILIM1, ILIM, MODE to GND ................-0.3V to +6V
PGND to GND .......................................................-0.3V to +0.3V
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C) .......666.7mW
20-Pin QSOP (derate 9.1mW/°C above +70°C) .......727.3mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER CONDITIONS
MIN TYP MAX
UNITS
Operating Input Voltage Range VL connected to IN for V
IN
< 5.5V 3.0
13.2
V
Quiescent Supply Current V
FB
= 0.9V, no switching 2 3 mA
EN = GND, MODE = GND, IN not connected to VL
10
Shutdown Supply Current
EN = GND, VL = IN, MODE = GND 20
µA
VL Undervoltage-Lockout Trip Level V
VL
rising, typical hysteresis is 80mV
2.52
2.7
2.88
V
Output Voltage Adjust Range (V
OUT
) (Note 1) 0.8 V
VL Output Voltage 5.5V < V
IN
< 13.2V, 1mA < I
VL
< 75mA 4.5 5 5.5 V
VL Output Current 75 mA
VOLTAGE REFERENCE
SS Shutdown Resistance From SS to GND, V
EN
= 0V 20
100
Ω
SS Soft-Start Current V
REF
= 0.625V 14 24 34 µA
Soft-Start Ramp Time Output from 0% to 100%, C
REF
= 0.01µF to 1µF 33
ms/µF
ERROR AMPLIFIER
FB Regulation Voltage
0.792
0.8
0.808
V
Transconductance 70
110 160
µS
COMP Shutdown Resistance From COMP to GND, V
EN
= 0V 20
100
Ω
FB Input Leakage Current V
FB
= 0.9V 5
100
nA
FB Input Common-Mode Range
-0.1 +0.9
V
CURRENT-SENSE AMPLIFIER
V
ILIM1
= 0V 8.8 11
13.2
V
ILIM1
= (1/3)V
VL
4.8 6 7.2
V
ILIM1
= (2/3)V
VL
3.2 4 4.8
Voltage Gain V
OUT
= 0 to 13V
V
ILIM1
= V
VL
2.4 3 3.6
V / V
CURRENT LIMIT
ILIM2 Output Current (MAX8544 Only) R
ILIM2
= 50kΩ to 200kΩ 4.5 5 5.5 µA
ILIM1 Input Current V
ILIM1
= 0V or V
VL
-1 +1 µA