Datasheet

MAX1970/MAX1971/MAX1972
Dual, 180° Out-of-Phase, 1.4MHz, 750mA Step-
Down Regulator with POR and RSI/PFO
10 ______________________________________________________________________________________
5ms/div
5V/div
MAX1970TOC17
SHUTDOWN RESPONSE
POR
EN
V
OUT1
V
OUT2
MAX1970
V
IN
= 5V
V
OUT1
= 3.3V, V
OUT2
= 2.5V
I
OUT1
= 375mA, I
OUT2
= 375mA
Typical Operating Characteristics (continued)
(T
A
= +25°C, unless otherwise noted.)
NAME
PIN
MAX1970/MAX1972 MAX1971
FUNCTION
1 LX1 LX1 Inductor Connection 1. Connect an inductor between LX1 and OUT1.
2V
CC
V
CC
Analog Supply Voltage. Bypass with 0.1µF to ground.
3 COMP1 COMP1
OUT1 Regulator Compensation. Connect series RC network from COMP1 to GND.
COMP1 is pulled to GND when the outputs are shut down. See the Compensation
Design section for component values.
4 FB1 FB1
OUT1 Feedback. Connected to OUT1 for internal mode (FBSEL1 = GND or V
CC
).
Use an external resistor-divider from OUT1 to GND to set the output voltage from
1.2V to V
IN
for external mode (FBSEL1 = unconnected). See the Output Voltage
Selection section for <1.2V output.
5 FB2 FB2
OUT2 Feedback. Connected to OUT2 for internal mode (FBSEL2 = GND or V
CC
).
Use an external resistor-divider from OUT2 to GND to set the output voltage from
1.2V to V
IN
for external mode (FBSEL2 = unconnected). See the Output Voltage
Selection section for <1.2V output.
6 COMP2 COMP2
OUT2 Regulator Compensation. Connect series RC network from COMP2 to GND.
COMP2 is pulled to GND when the outputs are shut down. See the Compensation
Design section for component values.
7 REF REF
Reference. Bypass with 0.01µF to 1.0µF capacitor. REF controls the soft-start
ramp and is pulled to GND when the outputs are shut down.
8 GND GND Ground
Pin Description