Datasheet

6 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)
Note 2: All devices are 100% production tested at T
A
= +25NC. Limits over temperature are guaranteed by design.
Note 3: See the Output Short-Circuit Protection with Hiccup Mode section.
Note 4: The parameter is measured at the trip point of latch with V
FB
= 0V. Gain is defined as DV
COMP
/DV
CSSC
for 0.15V <
DV
CSSC
< 0.25V.
Note 5: Operates over the -40NC to +125NC operating temperature range.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
ERROR AMPLIFIER
FB Reference Voltage V
REF
V
FB
when I
COMP
=
0, V
COMP
= 2.5V
MAX5974A/B 1.5 1.52 1.54
V
MAX5974C/D 1.202 1.215 1.227
MAX5974DATE
(Note 5)
1.202 1.215 1.230
FB Input Bias Current I
FB
V
FB
= 0 to 1.75V
MAX5974A/B -250 +250
nA
MAX5974C/D -500 +100
MAX5974DATE
(Note 5)
-1000 +100
Voltage Gain A
EAMP
80 dB
Transconductance g
M
MAX5974A/B 1.8 2.55 3.2
mS
MAX5974C/D 1.8 2.66 3.5
Transconductance Bandwidth BW
Open loop (typical
gain = 1) -3dB
frequency
MAX5974A/B 2
MHz
MAX5974C/D 30
Source Current V
FB
= 1V, V
COMP
= 2.5V 300 375 455 FA
Sink Current V
FB
= 1.75V, V
COMP
= 1V 300 375 455 FA
FREQUENCY FOLDBACK (FFB)
V
CSAVG
-to-FFB Comparator
Gain
10 V/V
FFB Bias Current I
FFB
V
FFB
= 0V,
V
CS
= 0V (not in
FFB mode)
-40°C to +85°C 26 30 33
FA
-40°C to +125°C 26 30 33.5
NDRV Switching Frequency
During Foldback
f
SW-FB
f
SW
/2 kHz