Datasheet

MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup Circuit
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 13V, a 10µF capacitor connects V
CC
to GND, V
CS
= 0, V+ = 48V, 0.1µF capacitor connected from SS_SHDN to GND, NDRV
= open circuit, V
FB
= 3V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SLOPE COMPENSATION
Slope Compensation
(MAX5019 only)
V
SCOMP
26 mV/µs
THERMAL SHUTDOWN
Thermal Shutdown Temperature 150 °C
Thermal Hysteresis 25 °C
CURRENT LIMIT
CS Threshold Voltage V
ILIM
FB = GND 419 465 510 mV
CS Input Bias Current 0 ≤ V
CS
≤ 2V, FB = GND -1 1 µA
Current Limit Comparator
Propagation Delay
50mV overdrive on CS, FB = GND 180 ns
CS Blanking Time FB = GND, only PWM comparator is blanked 70 ns
OSCILLATOR
Clock Frequency Range FB = GND 247 275 302 kHz
MAX5019, FB = GND 75 85
Max Duty Cycle
MAX5020, FB = GND 44 50
%
SOFT-START
SS Source Current I
SSO
V
SS_SHDN
= 0 2.0 4.5 6.5 µA
SS Sink Current 1.0 mA
Steady State Reference Voltage
at SS_SHDN
V
SS
_SHDN No external load 2.331 2.420 2.500 V
V
SS_SHDN
falling 0.25 0.37 0.41
Shutdown Threshold
V
SS_SHDN
rising 0.53 0.59 0.65
V
Typical Operating Characteristics
(V+ = 48V, V
DD
= 13V, CS = GND, NRDV is open circuit, T
A
= +25°C, unless otherwise noted.)
0.999
1.000
1.001
1.002
1.003
-40 0-20 20 40 60 80
V
SS_SHDN
vs. TEMPERATURE
(AT THE END OF SOFT-START)
MAX5019 toc01
TEMPERATURE (°C)
V
FB
= 4V
V
SS_SHDN
(V) (NORMALIZED TO V
REF
= 2.4V)
273
274
276
275
277
278
-40 0-20 20 40 60 80
NDRV FREQUENCY
vs. TEMPERATURE
MAX5019 toc02
TEMPERATURE (°C)
NDRV FREQUENCY (kHz)
FB = GND
80.4
80.6
80.5
80.8
80.7
80.9
81.0
-40 20 40-20 0 60 80
MAX5019
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
MAX5019 toc03
TEMPERATURE (°C)
MAXIMUM DUTY CYCLE (%)
FB = GND