
M
16μA I
Q
, 1.2A PWM DC-DC
Step-Down Converters
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
IN, INP, OUT, D2,
SHDN
to GND..........................-0.3V to +6.0V
SS, D1 to GND.............................................-0.3V to (V
IN
+ 0.3V)
PGND to GND .......................................................-0.3V to +0.3V
LX Current (Note 1)...........................................................±2.25A
Output Short-Circuit Duration.....................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
10-Pin TDFN (derate 24.4mW/°C above +70°C) .......1951mW
ELECTRICAL CHARACTERISTICS
(V
IN
= V
INP
= V
SHDN
= 3.6V, T
A
= - 40°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise noted.) (Note 1)
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.
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
PARAMETER
CONDITIONS
MIN
2.6
2.20
TYP
MAX
5.5
2.55
25
42
1
UNITS
V
V
Input Voltage
Undervoltage-Lockout Threshold
V
IN
rising and falling, 35mV hysteresis (typ)
No switching, D1 = D2 = GND
Dropout
2.35
16
27
0.1
0.1
Quiescent Supply Current
μA
T
A
= +25°C
T
A
= +85°C
Shutdown Supply Current
SHDN
= GND
μA
Output Voltage Range
0.75
-0.25
-0.75
-1.5
-2.75
-0.75
-1.5
-2.25
-4.0
1200
600
V
IN
+1.75
+0.75
0
-1.25
+2.25
+1.5
+0.50
-1.0
V
No load
300mA load
600mA load
1200mA load, MAX1556 only
No load
300mA load
600mA load
1200mA load, MAX1556 only
+0.75
0
-0.75
-2.25
T
A
= 0°C to +85°C
(Note 2)
Output Accuracy
T
A
= -40°C to +85°C
(Note 2)
%
MAX1556
MAX1557
Maximum Output Current
mA
T
A
= +25°C
T
A
= +85°C
0.01
0.01
3
+0.75
0
-0.75
-2.25
0.1
D1 = D2 = GND
OUT Bias Current
For preset output voltages
4.5
+1.75
+1.2
+0.25
-1.25
+2.25
+1.50
+0.25
-1.00
μA
No load
300mA load
600mA load
1200mA load, MAX1556 only
No load
300mA load
600mA load
1200mA load, MAX1556 only
-0.50
-1.2
-1.75
-3.25
-1.25
-1.75
-2.75
-4.25
D1 = D2 = GND,
V
OUT
= 0.75V at
300mA (typ),
T
A
= 0°C to +85°C
FB Threshold Accuracy
D1 = D2 = GND,
V
OUT
= 0.75V
at 300mA (typ),
T
A
= -40°C to +85°C
%
Note 1:
LX has internal clamp diodes to GND and IN. Applications that forward bias these diodes should take care not to exceed
the IC’s package power-dissipation limits.