Rainbow Electronics MAX5974D - Manual (Page 7)

MAX5974A/MAX5974B/MAX5974C/MAX5974D
Active-Clamped, Spread-Spectrum,
Current-Mode PWM Controllers
7
Typical Operating Characteristics (continued)
(V IN = 12V (for MAX5974A/MAX5974C, bring V IN up to 21V 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, unless otherwise noted.)
SOFT-START CHARGING CURRENT
vs. TEMPERATURE
MAX5974A/B/C/D toc10
TEMPERATURE (°C)
SOFT-START CHARGING CURRENT (µA)
60 35 10 -15
9.98
9.99
10.00
10.01
10.02
10.03
10.04
10.05
10.06
9.97
-40 85
SWITCHING FREQUENCY
vs. R RT VALUE
MAX5974A/B/C/D toc11
R RT VALUE (k Ω)
SWITCHING FREQUENCY (kHz)
100
1000
10
100 10
SWITCHING FREQUENCY
vs. TEMPERATURE
MAX5974A/B/C/D toc12
TEMPERATURE (°C)
SWITCHING FREQUENCY (kHz)
60 35 -15 10
245
246
247
248
250
249
251
252
244
-40 85
FREQUENCY DITHERING
vs. R DITHER
MAX5974A/B/C/D toc13
R DITHER (k Ω)
FREQUENCY DITHERING (%)
900 800 700 600 500 400
2
4
6
8
10
12
14
0
300 1000
MAXIMUM DUTY CYCLE
vs. SWITCHING FREQUENCY
MAX5974A/B/C/D toc14
SWITCHING FREQUENCY (kHz)
MAXIMUM DUTY CYCLE (%)
700 600 100 200 300 400 500
76
77
78
79
80
81
82
83
75
0 800
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
MAX5974A/B/C/D toc15
TEMPERATURE (°C)
MAXIMUM DUTY CYCLE (%)
60 35 -15 10
80.3
80.4
80.5
80.6
80.8
80.7
80.9
81.0
80.2
-40 85
MAXIMUM DUTY CYCLE
vs. SYNC FREQUENCY
MAX5974A/B/C/D toc16
SYNC FREQUENCY (kHz)
MAXIMUM DUTY CYCLE (%)
450 400 350 300
5
10
15
20
25
30
35
40
45
0
250 500
V SS = 0.5V
MAXIMUM DUTY CYCLE
vs. V SS
MAX5974A/B/C/D toc17
V SS (V)
MAXIMUM DUTY CYCLE (%)
2.0 1.5 1.0 0.5
10
20
30
40
50
60
70
80
90
100
0
0 2.5
MAXIMUM DUTY CYCLE
vs. V DCLMP
MAX5974A/B/C/D toc18
V DCLMP (V)
MAXIMUM DUTY CYCLE (%)
2.0 1.5 1.0 0.5
10
20
30
40
50
60
70
80
90
100
0
0 2.5