Owner's manual

MAX1947
Low Input/Output Voltage
Step-Up DC-DC Converter with
RESET
_______________________________________________________________________________________ 3
Note 2: Limits are 100% production tested at T
A
= +25°C. Limits over the operating temperature range are guaranteed by design.
Note 3: When BATT is greater than the output-voltage set point, the part is in track mode (see the Track Mode section).
ELECTRICAL CHARACTERISTICS (continued)
(V
BATT
= 1.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Startup to Normal-Mode Output
Transition Voltage
50mV hysteresis, rising edge 1.40 1.62 1.73 V
T
A
= 0°C to +85°C 600 800 1000
NFET Current Limit
T
A
= -40°C to +85°C 580 800 1000
mA
T
A
= 0°C to +85°C 15 75 150
PFET Turn-Off Current
T
A
= -40°C to +85°C 10 75 150
mA
MAX1947ETA18 0.3 0.6
MAX1947ETA25 0.22 0.44
MAX1947ETA30 0.17 0.34
Internal NFET
On-Resistance
I
LX
= 100mA
MAX1947ETA33 0.15 0.3
Ω
MAX1947ETA18 0.5 1.0
MAX1947ETA25 0.35 0.7
MAX1947ETA30 0.28 0.56
Internal PFET
On-Resistance
I
LX
= 100mA
MAX1947ETA33 0.25 0.5
Ω
T
A
= +25°C 0.1 1
LX Leakage Current
SHDN = GND, V
OUT
= 0V,
V
LX
= 3.6V
T
A
= +85°C 1
µA
SHUTDOWN MODE
Shutdown Supply Current SHDN = GND 2 4 µA
V
IH
0.8 x
V
BATT
SHDN Input Voltage
V
IL
0.18 x
V
BATT
V
SHDN = OUT or GND, T
A
= +25°C1100
SHDN Input Bias Current
SHDN = OUT or GND, T
A
= +85°C5
nA
OUT Discharge Resistance in
Shutdown
SHDN = GND 500 1000 Ω
RESET OUTPUT
Reset OUT Voltage Trip Level V
OUT
falling, 1% hysteresis 87 90 93 %
Minimum V
OUT
for Valid Reset 0.9 V
Reset Timeout 65 140 235 ms
I
SINK
= 200µA 0.3
RESET Output Voltage
I
SOURCE
= 200µA 0.8 x V
OUT
V