Rainbow Electronics MAX1623 User Manual
Page 2
MAX1623
3A, Low-Voltage, Step-Down Regulator with
Synchronous Rectification and Internal Switches
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= V
CC
= 5V, FBSEL unconnected, R
TOFF
= 110k
Ω, 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.
IN to PGND .....................................................................0V to 6V
V
CC
to GND ................................................................-0.3V to 6V
PGND to GND.....................................................................±0.5V
IN to V
CC
.............................................................................±0.5V
LX Current (Note 1).............................................................±5.5A
SHDN to GND .............................................................-0.3V to 6V
REF, FBSEL, COMP, FB, TOFF to GND .....-0.3V to (V
CC
+ 0.3V)
REF Short to GND ......................................................Continuous
Continuous Power Dissipation (T
A
= +70°C) (with part mounted
on 1 sq. inch of one ounce copper)
20-Pin SSOP (derate 22mW/°C above +70°C) ................1.3W
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
SHDN = GND or V
CC
FBSEL = REF
FBSEL = GND
V
IN
= 4.5V to 5.5V,
I
LOAD
= 0 to 3A
(Note 2)
FBSEL = GND, adjustable output mode, V
FB
= 1.2V
V
CC
falling, 100mV hysteresis
I
LOAD
≥ 1.5A (Note 2)
V
IN
= 4.5V
SHDN = GND
V
IN
= 4.5V
FBSEL = GND or REF (Note 2)
I
REF
= 0
Does not include switching losses
I
REF
= -1µA to 10µA
CONDITIONS
V
0.8
SHDN Input Low Voltage
µA
-1
0.03
1
SHDN Input Current
2
%
1
AC Output Load Regulation
µs
0.85
1.00
1.15
Off-Time Default Period
µs
0.5
4
Off-Time Adjustment Range
kHz
500
Error-Amplifier Gain Bandwidth
nA
-25
25
FB Input Bias Current
V
4.1
4.2
4.3
Undervoltage Lockout Threshold
°C
145
Thermal Shutdown Threshold
µA
0.5
10
Shutdown Supply Current
µA
400
525
No-Load Supply Current
A
1
1.25
1.5
Idle Mode Threshold (Note 3)
2.49
2.525
2.550
V
3.296
3.330
3.366
V
4.5
5.5
Input Voltage Range
Output Voltage
kHz
350
Maximum Switching Frequency
m
Ω
60
100
NMOS Switch On-Resistance
m
Ω
55
100
PMOS Switch On-Resistance
A
3.65
4.65
Current-Limit Threshold
1.089
1.100
1.110
V
V
REF
3.80
Output Adjustment Range
V
1.089
1.100
1.110
Reference Output Voltage
mV
1
Reference Load Regulation
UNITS
MIN
TYP
MAX
PARAMETER
FBSEL = unconnected
FBSEL = V
CC
FBSEL = GND or REF
V
2
SHDN Input High Voltage
V
IN
= 5.5V, V
LX
= 5.5V or 0
µA
±20
LX Leakage Current
A
3.65
RMS LX Output Current
Note 1: LX has internal clamp diodes to PGND and IN. Applications that forward bias these diodes should take care not to exceed
the IC’s package power dissipation limits.