Datasheet

MAX1953/MAX1954/MAX1957
Low-Cost, High-Frequency, Current-Mode PWM
Buck Controller
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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, FB to GND...........................................................-0.3V to +6V
LX to BST..................................................................-6V to +0.3V
BST to GND ............................................................-0.3V to +20V
DH to LX....................................................-0.3V to (V
BST
+ 0.3V)
DL, COMP to GND.......................................-0.3V to (V
IN
+ 0.3V)
HSD, ILIM, REFIN to GND ........................................-0.3V to 14V
PGND to GND .......................................................-0.3V to +0.3V
I
DH
, I
DL
................................................................±100mA (RMS)
Continuous Power Dissipation (T
A
= +70°C)
(derate 5.6mW/°C above +70°C)..................................444mW
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
ELECTRICAL CHARACTERISTICS
(V
IN
= 5V, V
BST
- V
LX
= 5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Operating Input Voltage Range 3.0 5.5 V
HSD Voltage Range MAX1954 only (Note 2) 3.0 13.2 V
Quiescent Supply Current V
FB
= 1.5V, no switching 1 2 mA
Standby Supply Current (MAX1953/ MAX1957) V
IN
= V
BST
= 5.5V, COMP = GND 220 350 µA
Standby Supply Current (MAX1954)
V
IN
= V
BST
= 5.5V, V
HSD
= 13.2V,
COMP = GND
220 350 µA
Undervoltage Lockout Trip Level Rising and falling V
IN
, 3% hysteresis 2.50 2.78 2.95 V
Output Voltage Adjust Range (V
OUT
) 0.8
0.86 x
V
IN
V
ERROR AMPLIFIER
T
A
= 0°C to +85°C (MAX1953/MAX1954) 0.788 0.8 0.812
T
A
= -40°C to +85°C (MAX1953/MAX1954) 0.776 0.8 0.812
FB Regulation Voltage
MAX1957 only
V
REFIN
- 8mV
V
REFIN
V
REFIN
+ 8mV
V
Transconductance 70 110 160 µS
FB Input Leakage Current V
FB
= 0.9V 5 500 nA
REFIN Input Bias Current V
REFIN
= 0.8V, MAX1957 only 5 500 nA
FB Input Common-Mode Range -0.1 1.5 V
REFIN Input Common-Mode Range MAX1957 only -0.1 1.5 V
Current-Sense Amplifier Voltage Gain Low ILIM = GND (MAX1953 only) 5.67 6.3 6.93 V/V
V
ILIM
= V
IN
or ILIM = open (MAX1953 only)
Current-Sense Amplifier Voltage Gain
MAX1954/MAX1957
3.15 3.5 3.85 V/V