Datasheet
MAX1973/MAX1974
Smallest 1A, 1.4MHz Step-Down Regulators
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, POK, CTL1, CTL2, FBSEL, ON to GND ..............-0.3V to +6V
COMP, FB, SS to GND ................................-0.3V to (V
IN
+ 0.3V)
PGND to GND .......................................................-0.3V to +0.3V
LX Current (Note 1) ...............................................-2.4A to +2.4A
Continuous Power Dissipation (T
A
= +70°C)
10-Pin µMAX (derate 5.6mW/°C above +70°C) .......... 444mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V
IN
= V
CTL_
= 3.3V, FB = OUT, T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER CONDITIONS
MIN TYP MAX UNITS
IN
IN Voltage Range 2.6 5.5 V
IN Undervoltage Lockout
Threshold
Rising and falling, hysteresis is 25mV (typ) 2.2
2.35
2.5 V
Supply Current Switching with no load 4.0 7.5 mA
Supply Current in Dropout V
OUT
set for 3.6V 3 5 mA
Shutdown Supply Current V
IN
= 5.5V 0.1 10 µA
FB
MAX1973
1.25
V
IN
Output Voltage Range
MAX1974
0.75
V
IN
V
FBSEL not connected
1.2375 1.25 1.2625
FBSEL = GND
1.7820
1.8
1.8180
MAX1973
FBSEL = IN
2.4750
2.5
2.5250
FBSEL not connected
0.7425 0.75 0.7575
FBSEL = GND
0.99 1.00 1.01
FB Regulation Voltage
MAX1974
FBSEL = IN
1.485 1.500 1.515
V
FB Regulation Voltage
Positive Voltage Margining
MAX1973, CTL1 = GND, CTL2 = IN +3 +4 +5 %
FB Regulation Voltage
Negative Voltage Margining
MAX1973, CTL1 = IN, CTL2 = GND -3 -4 -5 %
FB Input Resistance to GND in
Preset Output Modes
10 30 70 kΩ
FB Input Bias Current FBSEL not connected
-0.1 0.01 +0.1
µA
SS (REFERENCE OUTPUT)
MAX1974
0.75
SS Voltage
MAX1973
1.25
V
Note 1: LX has internal clamp diodes to IN and PGND. Applications that forward bias these diodes should take care not to exceed
the IC package power dissipation limit.