Datasheet

MAX1970/MAX1971/MAX1972
Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
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, EN, FBSEL1, FBSEL2, PFO, POR,
RSI, V
CC
to GND ...................................................-0.3V to +6V
COMP1, COMP2, FB1, FB2,
REF to GND.............................................-0.3V to (V
CC
+ 0.3V)
LX1, LX2 to PGND .......................................-0.3V to (V
IN
+ 0.3V)
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)...........667mW
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
CC
= V
EN
= 5V, R
POR
= 100kΩ to IN, R
PFO
= 100kΩ to IN, V
RSI
= 0, C
REF
= 0.1µF, FBSEL1 = unconnected, FBSEL2 =
unconnected, 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 AND V
CC
IN Voltage Range 2.6 5.5 V
MAX1971 5 10
IN Supply Current
Switching with no load
V
IN
= 3.3V
MAX1970/MAX1972 10 20
mA
MAX1970/MAX1972 1 100
IN Shutdown Current V
IN
= 5.5V, V
EN
= 0
MAX1971 1 60
µA
V
CC
rising 2.40 2.55
V
CC
Undervoltage
Lockout Threshold
V
CC
falling 2.20 2.35
V
REF
REF Voltage I
REF
= 0, V
IN
= 2.6V to 5.5V 1.188 1.200 1.212 V
REF Shutdown Resistance REF to GND, V
EN
= 0 10 25 Ω
REF Soft-Start Current V
REF
= 1V 20 25 30 µA
FB1 AND FB2
FB_ Regulation Voltage
FBSEL_ = unconnected, OUT1 = FB1, OUT2 = FB2,
V
COMP_
= 1.20V to 1.80V, V
IN
= 2.6V to 5.5V
1.188 1.200 1.212 V
OUT_ Voltage Range FBSEL_ = unconnected 1.2 V
IN
V
V
IN
= 2.6V to 5.5V V
COMP1
= 1.2V, FBSEL1= GND 1.782 1.800 1.818
OUT1 Regulation Voltage
V
IN
= 4.5V to 5.5V V
COMP1
= 1.2V, FBSEL1 = V
CC
3.2670 3.3 3.330
V
V
COMP2
= 1.2V, FBSEL2 = GND 1.485 1.5 1.150
OUT2 Regulation Voltage V
IN
= 2.6V to 5.5V
V
COMP2
= 1.2V, FBSEL2 = V
CC
2.475 2.5 2.525
V
Maximum Output Current Guaranteed by design (Note 1) 750 mA
FBSEL1 = GND 30 60 120
FB1 Input Resistance
Measured from FB1 to
GND
FBSEL1 = V
CC
30 60 120
kΩ
FBSEL2 = GND 22.5 45 90
FB2 Input Resistance
Measured from FB2 to
GND
FBSEL2 = V
CC
22.5 45 90
kΩ
FB_ Input Bias Current FB1 or FB2, FBSEL_ = unconnected, V
FB1
= V
FB2
= 1.15V 0.01 0.1 µA