Datasheet

MAX1973/MAX1974
Smallest 1A, 1.4MHz Step-Down Regulators
_______________________________________________________________________________________ 5
ELECTRICAL CHARACTERISTICS
(V
IN
= V
CTL_
= 3.3V, FB = OUT, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER CONDITIONS
MIN
TYP
MAX
UNITS
SS to GND Resistance
in Shutdown
5 40 100 Ω
FBSEL
Low Input Threshold 0.3 V
High Input Threshold
V
IN
-
0.4
V
Input Bias Current FBSEL = GND or IN, V
IN
= 5.5V -20
+20
µA
COMP
Transconductance
from FB to COMP
40 80 µS
COMP to GND Resistance
in Shutdown
5 100 Ω
Clamp Voltage Low 0.6 1.2 V
Clamp Voltage High 1.3 2.2 V
LX
On-Resistance High V
IN
= 3.3V
0.46
Ω
On-Resistance Low V
IN
= 3.3V
0.32
Ω
Current-Sense Transresistance
0.275 0.425
V/A
Positive Current-Limit Threshold
1.10 1.85
A
Negative Current-Limit Threshold
-1.20 -0.35
A
V
LX
= V
IN
= 5.5V 20
LX Shutdown Leakage Current
LX = GND, V
IN
= 5.5V -20
µA
Switching Frequency 1.2 1.6
MHz
CTL1, CTL2 (MAX1973), ON (MAX1974)
Logic-Low Input Threshold 0.6 V
Logic-High Input Threshold 1.6 V
Logic Input Current -1 1 µA
POK (MAX1974 only)
Output Low Voltage POK sinking 1mA 100 mV
Rising 90 95
Output Valid Threshold
for POK
Percentage of nominal
regulation voltage
Falling 88 92
%
Note 2: Specifications to -40°C are guaranteed by design and not production tested.