Datasheet

MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
_______________________________________________________________________________________ 9
Typical Operating Characteristics (continued)
(V
CC
= 15V, T
A
= +25°C, unless otherwise noted.)
Pin Descriptions
PIN NAME FUNCTION
1 COMP Error-Amplifier Output. COMP can be used for soft-start.
2 FB Error-Amplifier Inverting Input
3CS
PWM Comparator and Overcurrent Protection Comparator Input. The current-sense signal is
compared to a signal proportional to the error-amplifier output voltage.
4R
T
/C
T
Timing Resistor/Capacitor Connection. A resistor R
T
from R
T
/C
T
to REF and capacitor C
T
from R
T
/C
T
to GND set the oscillator frequency.
5 GND
Power-Supply Ground. Place the V
CC
and REF bypass capacitors close to the IC to minimize ground
loops.
6 OUT MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.
7V
CC
Power-Supply Input. Bypass V
CC
to GND with a 0.1µF ceramic capacitor or a parallel combination of
a 0.1µF and a higher value ceramic capacitor.
8 REF
5V Reference Output. Bypass REF to GND with a 0.1µF ceramic capacitor or a parallel combination
of a 0.1µF and a higher value ceramic capacitor no larger then 4.7µF.
MAX5094_
t = 400ns/div
OUT SOURCE AND SINK CURRENTS
I
OUT
4A/div
V
OUT
10V/div
MAX5094/95 toc20
V
CC
= 15V
C
OUT
= 10nF
2.0
3.0
2.5
4.0
3.5
5.0
4.5
5.5
6.5
6.0
7.0
20 220 320 420120 520 620 720 920820 1020
SUPPLY CURRENT
vs. OSCILLATOR FREQUENCY
MAX5094/95 toc21
FREQUENCY (kHz)
I
CC
(mA)
T
A
= +125°C
MAX5095C
C
T
= 100pF
T
A
= -40°C
MAXIMUM DUTY CYCLE
vs. R
T
MAX5094A/MAX5095A
MAX5094/95 toc22
R
T
(
Ω
)
DUTY CYCLE (%)
10,0001000
30
40
50
60
70
80
90
100
20
100 100,000
C
T
= 100nF
C
T
= 560pF
C
T
= 220pF
C
T
= 1000pF