Datasheet

MAX1556/MAX1556A/MAX1557
16µA I
Q
, 1.2A PWM DC-DC
Step-Down Converters
_______________________________________________________________________________________ 3
Note 2: All units are 100% production tested at T
A
= +25°C. Limits over the operating range are guaranteed by design.
Note 3: For the MAX1556, 3.3V output accuracy is specified with a 4.2V input.
ELECTRICAL CHARACTERISTICS (continued)
(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 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
= 2.6V to 3.6V -0.37
MAX1556,
D1 = IN, D2 = GND;
MAX1556A
D1 = D2 = IN
V
IN
= 3.6V to 5.5V 0.33
V
IN
= 2.6V to 3.6V -0.1
Line Regulation
MAX1557,
D1 = IN, D2 = GND
V
IN
= 3.6V to 5.5V 0.09
%
V
IN
= 3.6V 0.19 0.35
MAX1556/MAX1556A
V
IN
= 2.6V 0.23
V
IN
= 3.6V 0.35 0.7
p-Channel On-Resistance
MAX1557
V
IN
= 2.6V 0.42
Ω
V
IN
= 3.6V 0.27 0.48
n-Channel On-Resistance
V
IN
= 2.6V 0.33
Ω
MAX1556/MAX1556A 1.5 1.8 2.1
p-Channel Current-Limit
Threshold
MAX1557 0.8 1.0 1.2
A
n-Channel Zero Crossing
Threshold
20 35 45 mA
MAX1556/MAX1556A 1.8
RMS LX Output Current
MAX1557 1.0
A
RMS
T
A
= +25°C 0.1 10
LX Leakage Current
V
IN
= 5.5V, LX =
GND or IN
T
A
= +85°C 0.1
µA
Maximum Duty Cycle 100 %
Minimum Duty Cycle 0%
Internal Oscillator Frequency 0.9 1 1.1 MHz
SS Output Impedance ∆V
SS
/ I
SS
for I
SS
= 2µA 130 200 300 kΩ
SS Discharge Resistance SHDN = GND, 1mA sink current 90 200 Ω
Thermal-Shutdown Threshold +160 °C
Thermal-Shutdown Hysteresis 15 °C
LOGIC INPUTS (D1, D2, SHDN)
Input-Voltage High 2.6V ≤ V
IN
≤ 5.5V 1.4 V
Input-Voltage Low 0.4 V
T
A
= +25°C 0.1 1
Input Leakage
T
A
= +85°C 0.1
µA