MAX1678
1-Cell to 2-Cell, Low-Noise,
High-Efficiency, Step-Up DC-DC Converter
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
BATT
= V
SHDN
= 1.3V, I
LOAD
= 0, FB = GND, T
A
= 0°C to +85°C, 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.
Note 1: The reverse battery current is measured from the
Typical Operating Circuit’s
input terminal to GND when the battery is con-
nected backward. A reverse current of 220mA will not exceed package dissipation limits but, if left for an extended time
(more than 10 minutes), may degrade performance.
BATT, OUT,LX, SHDN to GND..............................-0.3V to +6.0V
OUT, LX Current.......................................................................1A
FB, PFI, PFO to GND................................-0.3V to (V
OUT
+ 0.3V)
Reverse Battery Current (T
A
= +25°C) (Note 1) ...............220mA
Continuous Power Dissipation (T
A
= +70°C)
µMAX (derate 4.1mW/°C above +70°C) .......................330mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +165°C
Lead Temperature (soldering, 10sec).............................+300°C
V
PFI
= 650mV, V
PFO
= 6V
R
L
= 3kΩ, T
A
= +25°C
V
PFI
= 0, V
OUT
= 3.3V, I
SINK
= 1mA
V
PFI
= 650mV
Falling PFI hysteresis 2%
V
FB
= 1.3V
I
LOAD
= 20mA, V
BATT
= 2.5V (Figure 7)
V
BATT
= 1V
I
DIODE
= 100mA, P-channel switch off
V
OUT
= 3.5V
V
OUT
= 3.3V
V
OUT
= 3.3V
V
FB
< 0.1V
External feedback
V
OUT
= 3.5V
External feedback
0.9V < V
BATT
< 3.3V (t
ON
= K / V
BATT
)
CONDITIONS
V0.8 x V
BATT
V
IH
SHDN Input High Voltage
V0.2 x V
BATT
V
IL
SHDN Input Low Voltage
µA0.01 1PFO Leakage Current
V0.04 0.4V
OL
PFO Low Output Voltage
nA0.1 10PFI Input Current
mV590 614 632V
IL,PFI
PFI Trip Voltage
nA0.1 10FB Input Current
%90
η
Efficiency
µA2 3.5I
SHDN,BATT
Shutdown Current into BATT
µA0.1 1I
SHDN,OUT
Shutdown Current into OUT
µA4 8I
Q,BATT
Quiescent Current into BATT
µA37 65I
Q,OUT
Quiescent Current into OUT
V-µs5.60 8 11.2KOn-Time Constant
V0.87Start-Up Voltage (Note 2)
V5.5V
BATT(MAX)
V0.7V
BATT(MIN)
Minimum Operating Input
Voltage
Maximum Operating Input
Voltage
mA550I
LX(MAX)
Maximum Peak LX Current
V0.8P-Channel Catch Diode Voltage
Ω1.5 2.2P-Channel On-Resistance
Ω1 1.5N-Channel On-Resistance
mV/°C-2Start-Up Voltage Tempco
V3.16 3.3 3.44V
OUT
Output Voltage (Fixed Mode)
V2.0 5.5
Output Voltage Range
(Adjustable Mode)
V1.19 1.23 1.26V
FB
FB Set Voltage
UNITSMIN TYP MAXSYMBOLPARAMETER
SHDN = GND or BATT
nA0.1 10
SHDN Input Current
