2a pwm dc-dc step-down converters, Electrical characteristics (continued) – Rainbow Electronics MAX1557 User Manual
Page 3
MAX1556/MAX1557
16µA I
Q
, 1.2A PWM DC-DC
Step-Down Converters
_______________________________________________________________________________________
3
Note 1: All units are 100% production tested at T
A
= +25°C. Limits over the operating range are guaranteed by design.
Note 2: 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 1)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN
= 2.6V to 3.6V
-0.37
MAX1556,
D1 = IN, D2 = GND
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
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
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
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
k
Ω
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