Rainbow Electronics MAX1557 - Manual (Page 4)

MAX1556/MAX1557
16µA I Q , 1.2A PWM DC-DC
Step-Down Converters
4 _______________________________________________________________________________________
Typical Operating Characteristics
(V IN = V INP = 3.6V, D1 = D2 = SHDN = IN, Circuits of Figures 2 and 3, T A = +25°C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
WITH 3.3V OUTPUT
MAX1556/7 toc01
LOAD CURRENT (mA)
EFFICIENCY (%)
100 10 1
60
70
80
90
100
50
40
0.1 1000 10,000
V IN = 5V
V IN = 3.6V
V IN = 4.2V
EFFICIENCY vs. LOAD CURRENT
WITH 2.5V OUTPUT
MAX1556/7 toc02
LOAD CURRENT (mA)
EFFICIENCY (%)
100 10 1
60
70
80
90
100
50
40
0.1 1000 10,000
V
IN
= 3.6V
V IN = 3V
V IN = 2.6V
V IN = 5V
EFFICIENCY vs. LOAD CURRENT
WITH 1.8V OUTPUT
MAX1556/7 toc03
LOAD CURRENT (mA)
EFFICIENCY (%)
100 10 1
60
70
80
90
100
50
40
0.1 1000 10,000
V IN = 5V
V
IN
= 3.6V
V IN = 3V
V IN = 2.6V
EFFICIENCY vs. LOAD CURRENT
WITH 1.0V OUTPUT (MAX1557)
MAX1556/7 toc04
LOAD CURRENT (mA)
EFFICIENCY (%)
100 10 1
60
70
80
90
100
50
40
0.1 1000
V IN = 5V
V IN = 3.6V
V
IN
= 3V
V IN = 2.6V
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX1556/7 toc05
LOAD CURRENT (mA)
OUTPUT VOLTAGE (V)
1000 800 600 400 200
1.75
1.76
1.77
1.78
1.79
1.80
1.81
1.82
1.83
1.84
1.74
0 1200
T
A
= -45 °C
T A = +25 °C
T
A
= +85 °C
OUTPUT VOLTAGE vs. INPUT VOLTAGE
WITH 600mA LOAD
MAX1556/7 toc06
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
5.0 4.5 4.0 3.5 3.0
1.780
1.781
1.782
1.783
1.784
1.785
1.786
1.787
1.788
1.789
1.779
2.5 5.5
T
A
= -40 °C
T A = +25 °C
T A = +85 °C
OUTPUT VOLTAGE vs. INPUT VOLTAGE
WITH NO LOAD
MAX1556/7 toc07
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
5.0 4.5 4.0 3.5 3.0
1.804
1.805
1.806
1.807
1.808
1.809
1.810
1.811
1.812
1.803
2.5 5.5
T A = -40 °C
T A = +25 °C
T
A
= +85 °C
SUPPLY CURRENT vs. INPUT VOLTAGE
MAX1556/7 toc08
INPUT VOLTAGE (V)
SUPPLY CURRENT (
µ
A)
5 4 3 2
2
4
6
8
10
12
14
16
18
20
0
1 6
HEAVY-LOAD SWITCHING WAVEFORMS
MAX1556/7 toc09
V OUT
AC-COUPLED
10mV/div
V LX
I LX
2V/div
0
0
400ns
500mA/div
I LOAD = 750mA