Rainbow Electronics MAX1847 User Manual
Page 4
MAX1846/MAX1847
High-Efficiency, Current-Mode,
Inverting PWM Controller
4
_______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS
(V
SHDN
= V
IN
= +12V, SYNC = GND, PGND = GND, R
FREQ
= 147k
Ω ±1%, C
VL
= 0.47µF, C
REF
= 0.1µF, T
A
= -40°C to +85°C,
unless otherwise noted.) (Note 3)
PARAMETER
CONDITIONS
MIN
MAX
UNITS
PWM CONTROLLER
Operating Input Voltage Range
3.0
16.5
V
V
IN
rising
2.95
UVLO Threshold
V
IN
falling
2.6
V
FB Threshold
No load
-20
20
mV
FB Input Current
V
FB
= -0.1V
-50
50
nA
Load Regulation
C
COMP
= 0.068µF, V
OUT
= -48V,
I
OUT
= 20mA to 200mA (Note 1)
-2
0
%
Current Limit Threshold
85
115
mV
CS Input Current
CS = GND
20
µA
Supply Current
V
FB
= -0.1V, V
IN
= +3.0V to +16.5V
1.2
mA
Shutdown Supply Current
SHDN = GND, V
IN
= +3.0V to +16.5V
25
µA
REFERENCE AND VL REGULATOR
REF Output Voltage
I
REF
= 50µA
1.225
1.275
V
REF Load Regulation
I
REF
= 0 to 500µA
-15
mV
VL Output Voltage
I
VL
= 100µA
3.85
4.65
V
VL Load Regulation
I
VL
= 0.1mA to 2.0mA
-60
mV
OSCILLATOR
R
FREQ
= 500k
Ω ±1%
84
116
Oscillator Frequency
R
FREQ
= 147k
Ω ±1%
255
345
kHz
R
FREQ
= 500k
Ω ±1%
93
98
Maximum Duty Cycle
R
FREQ
= 147k
Ω ±1%
84
93
%
SYNC Input Signal Duty-Cycle
Range
7
93
%
Minimum SYNC Input Logic Low
Pulse Width
200
ns
SYNC Input Rise/Fall Time
(Note 2)
200
ns
SYNC Input Frequency Range
100
550
kHz
DIGITAL INPUTS
POL, SYNC, SHDN Input High
Voltage
2.0
V
POL, SYNC, SHDN Input Low
Voltage
0.45
V