Low-Cost, High-Frequency, Current-Mode PWM
Buck Controller
MAX1953/MAX1954/MAX1957
ABSOLUTE MAXIMUM RATINGS
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
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.
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
Operating Input Voltage Range
HSD Voltage Range
Quiescent Supply Current
MAX1954 only (Note 2)
V
FB
= 1.5V, no switching
V
IN
= V
BST
= 5.5V, V
HSD
= 13.2V,
COMP = GND
Rising and falling V
IN
, 3% hysteresis
2.50
0.8
CONDITIONS
MIN
3.0
3.0
1
220
220
2.78
TYP
MAX
5.5
13.2
2
350
350
2.95
0.86 x
V
IN
0.8
0.8
V
REFIN
110
5
5
-0.1
MAX1957 only
ILIM = GND (MAX1953 only)
V
ILIM
= V
IN
or ILIM = open (MAX1953 only)
MAX1954/MAX1957
-0.1
5.67
3.15
6.3
3.5
0.812
0.812
V
REFIN
+ 8mV
160
500
500
1.5
1.5
6.93
3.85
µS
nA
nA
V
V
V/V
V/V
V
UNITS
V
V
mA
µA
µA
V
V
Standby Supply Current (MAX1953/ MAX1957) V
IN
= V
BST
= 5.5V, COMP = GND
Standby Supply Current (MAX1954)
Undervoltage Lockout Trip Level
Output Voltage Adjust Range (V
OUT
)
ERROR AMPLIFIER
T
A
= 0°C to +85°C
(MAX1953/MAX1954)
FB Regulation Voltage
T
A
= -40°C to +85°C
(MAX1953/MAX1954)
MAX1957 only
Transconductance
FB Input Leakage Current
REFIN Input Bias Current
FB Input Common-Mode Range
REFIN Input Common-Mode Range
Current-Sense Amplifier Voltage Gain Low
Current-Sense Amplifier Voltage Gain
V
FB
= 0.9V
V
REFIN
= 0.8V, MAX1957 only
0.788
0.776
V
REFIN
- 8mV
70
2
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
