Rainbow Electronics MAX859 User Manual
Page 2
MAX856–MAX859
3.3V/5V or Adjustable-Output,
Step-Up DC-DC Converters
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(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.)
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.
Supply Voltage (OUT to GND) ...................................-0.3V, +7V
Switch Voltage (LX to GND) .......................................-0.3V, +7V
S
—
H
—
D
—
N
–
, LBO to GND ....................................................-0.3V, +7V
LBI, REF, 3/
–
5
–
, FB to GND .........................-0.3V, (V
OUT
+ 0.3V)
Reference Current (I
REF
) ..................................................2.5mA
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) .........................471mW
µMAX (derate 4.1mW/°C above +70°C) ......................330mW
CERDIP (derate 8.00mW/°C above +70°C) .................640mW
Reverse Battery Current (T
A
≤
+45°C, Note 1) .................750mA
Operating Temperature Ranges
MAX85_C_ _ ......................................................0°C to +70°C
MAX85_E_ _ ....................................................-40°C to +85°C
MAX85_MJA .................................................-55°C to +125°C
Junction Temperature .....................................................+150°C
Storage Temperature Range ............................-65°C to +160°C
Lead Temperature (soldering, 10sec) ............................+300°C
Note 1:
Reverse battery current is measured from the
Typical Operating Circuit’s
battery input terminal to GND when the battery is
connected backwards. A reverse current of 750mA will not exceed the SO or CERDIP package dissipation limits but, if left
for an extended time (more than ten minutes), may degrade performance.
LBO = 5V
I
SINK
= 2mA
With falling edge
3/
–
5
–
= 3V, -20µA
≤
REF load
≤
250µA, C
REF
= 0.22µF
No REF load
MAX858/MAX859
I
LOAD
= 0mA, 3/
–
5
–
= 3V, LBI = 1.5V, V
OUT
= 3.47V,
(FB = 1.5V, MAX857/MAX859 only)
MAX856/MAX857
S
—
H
—
D
—
N
–
= 0V, 3/
–
5
–
= 3V, LBI = 1.5V, V
OUT
= 3.47V,
(FB = 1.5V, MAX857/MAX859 only)
2V
≤
V
IN
≤
3V
I
LOAD
= 0mA
Output set for 3.3V, measured at V
IN
in Figure 2, R3 omitted.
CONDITIONS
µA
1
LBO Output Leakage Current
V
0.4
LBO Output Voltage Low
mV
25
LBI Input Hysteresis
V
1.22
1.25
1.28
LBI Input Threshold
%
0.8
2.0
Reference-Voltage Regulation
V
1.23
1.25
1.27
Reference Voltage
mA
125
500
µA
1
5
Shutdown Quiescent Current
(Note 2)
1
µA
60
No Load Battery Current
4.80
5.0
5.20
3.17
3.3
3.43
4.80
5.0
5.20
µA
25
60
Quiescent Supply Current in
3.3V Mode (Note 2)
V
0.8
Minimum Operating Voltage
4.80
5.0
5.20
3.17
3.3
3.43
V
4.80
5.0
5.20
Output Voltage
V
0.8
1.8
Minimum Start-Up
Supply Voltage
UNITS
MIN
TYP
MAX
PARAMETER
Peak Inductor Current Limit
MAX856, 3/
–
5
–
= 0V, 0mA
≤
I
LOAD
≤
100mA
MAX856, 3/
–
5
–
= 3V, 0mA
≤
I
LOAD
≤
150mA
MAX857, V
OUT
= 5V, 0mA
≤
I
LOAD
≤
100mA
MAX858, 3/
–
5
–
= 0V, 0mA
≤
I
LOAD
≤
25mA
MAX858, 3/
–
5
–
= 3V, 0mA
≤
I
LOAD
≤
35mA
MAX859, V
OUT
= 5V, 0mA
≤
I
LOAD
≤
25mA
MAX85_C
MAX85_E/M