3.3V/5V or Adjustable-Output,
Step-Up DC-DC Converters
ELECTRICAL CHARACTERISTICS (continued)
(Circuits of Figure 2, V
IN
= 2.5V, I
LOAD
= 0mA, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at T
A
= +25°C.)
–— – –
— —
–
SHDN , 3/ 5 Input Voltage Low
— —
— – –
–
SHDN , 3/ 5 Input Voltage High
— —
— – –
–
SHDN , 3/ 5, FB, LBI Input Current
FB Voltage
Output Voltage Range
0.4
1.6
–— –
— —
–
–
LBI = 1.5V, FB = 1.5V, SHDN = 0V or 3V, 3/ 5 = 0V or 3V
MAX857/MAX859
MAX857/MAX859, I
LOAD
= 0mA (Note 3)
1.22
2.7
1.25
±100
1.28
6.0
V
V
nA
V
V
MAX856–MAX859
Note 2:
Supply current from the 3.3V output is measured with an ammeter between the 3.3V output and OUT pin. This current
correlates directly with actual battery supply current, but is reduced in value according to the step-up ratio and efficiency.
V
OUT
= 3.47V to keep the internal switch open when measuring the current into the device.
Note 3:
Minimum value is production tested. Maximum value is guaranteed by design and is not production tested.
__________________________________________Typical Operating Characteristics
(Circuits of Figure 2, T
A
= +25°C, unless otherwise noted.)
MAX858/MAX859
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 3.3V
MAX856-01
MAX858/MAX859
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 5V
90
80
V
IN
= 3.3V
MAX856-02
100
90
80
EFFICIENCY (%)
V
IN
= 2.0V
V
IN
= 1.5V
V
IN
= 2.5V
100
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.001
0.01
70
60
50
40
30
20
10
0
V
IN
= 1.5V
V
IN
= 2.5V
1
0.1
100
10
LOAD CURRENT (mA)
1000
0.001
0.01
1
0.1
100
10
LOAD CURRENT (mA)
1000
MAX856/MAX857
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 5V
90
80
EFFICIENCY (%)
V
IN
= 2.0V
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0.001 0.01
100
1
0.1
10
LOAD CURRENT (mA)
1000
V
IN
= 1.5V
V
IN
= 3.3V
MAX856-03
MAX856/MAX857
EFFICIENCY vs. OUTPUT CURRENT
V
OUT
= 3.3V
90
80
70
60
50
40
30
20
10
0
0.001 0.01
100
1
0.1
10
LOAD CURRENT (mA)
1000
V
IN
= 1.5V
V
IN
= 2.0V
V
IN
= 2.5V
MAX856-04
100
100
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
