Datasheet

4 Maxim Integrated
Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers
MAX5974A/MAX5974B/MAX5974C/MAX5974D
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= 12V (for MAX5974A/MAX5974C, bring V
IN
up to 17V for startup), V
CS
= V
CSSC
= V
DITHER/SYNC
= V
FB
= V
FFB
= V
DCLMP
=
V
GND
, V
EN
= +2V, NDRV = AUXDRV = SS = COMP = unconnected, R
RT
= 34.8kI, R
DT
= 25kI, C
IN
= 1FF, T
A
= -40NC to +85NC,
unless otherwise noted. Typical values are at T
A
= +25NC.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SOFT-START AND RESTART (SS)
Charging Current I
SS-CH
-40°C to +85°C 9.5 10 10.5
FA
-40°C to +125°C 9 10 11
Discharging Current
I
SS-D
V
SS
= 2V, normal shutdown 0.65 1.34 2 mA
I
SS-DH
(V
EN
< V
ENF
or V
IN
< V
INUVF
),
V
SS
= 2V, hiccup mode discharge for
t
RSTRT
(Note 3)
1.6 2 2.4 FA
Discharge Threshold to Disable
Hiccup and Restart
V
SS-DTH
0.15
V
Minimum Restart Time During
Hiccup Mode
t
RSTRT-MIN
1024
Clock
Cycles
Normal Operating High Voltage V
SS-HI
5 V
Duty-Cycle Control Range V
SS-DMAX
D
MAX
(typ) = (V
SS-DMAX
/2.43V) 0 2 V
DUTY-CYCLE CLAMP (DCLMP)
DCLMP Input Current I
DCLMP
V
DCLMP
= 0 to 5V -100 0 +100 nA
Duty-Cycle Control Range V
DCLMP-R
V
DCLMP
= 0.5V 73 75.4 77.5
%
D
MAX
(typ) =
1 - (V
DCLMP
/2.43V)
V
DCLMP
= 1V 54 56 58
V
DCLMP
= 2V 14.7 16.5 18.3
NDRV DRIVER
Pulldown Impedance R
NDRV-N
I
NDRV
(sinking) =
100mA
-40°C to +85°C 1.9 3.4
I
-40°C to +125°C 1.9 3.5
Pullup Impedance R
NDRV-P
I
NDRV
(sourcing) = 50mA 4.7 8.3
I
Peak Sink Current 1 A
Peak Source Current 0.65 A
Fall Time t
NDRV-F
C
NDRV
= 1nF 14 ns
Rise Time t
NDRV-R
C
NDRV
= 1nF 27 ns
AUXDRV DRIVER
Pulldown Impedance R
AUX-N
I
AUXDRV
(sinking)
= 50mA
-40°C to +85°C 4.3 7.7
I
-40°C to +125°C 4.3 7.95
Pullup Impedance R
AUX-P
I
AUXDRV
(sourcing) = 25mA 10.6 18.9
I
Peak Sink Current 0.5 A
Peak Source Current 0.3 A
Fall Time t
AUX-F
C
AUXDRV
= 1nF 24 ns
Rise Time t
AUX-R
C
AUXDRV
= 1nF 45 ns